Update version

Add VCC-GND YD-RP2040 board (#1120 )
Fixes #1109
2023-01-14 14:34:45 -08:00 · 2023-01-14 14:33:52 -08:00 · 2023-01-14 13:35:33 -08:00 · 2023-01-14 12:19:27 -08:00 · 2023-01-13 13:04:24 -08:00 · 2023-01-09 09:55:27 -08:00
155 changed files with 25461 additions and 14404 deletions
@@ -6,6 +6,10 @@ name: Arduino-Pico CI
 on:
  pull_request:

+env:
+  TRAVIS_BUILD_DIR: ${{ github.workspace }}
+  TRAVIS_TAG: ${{ github.ref }}
+

 jobs:

@@ -20,7 +24,7 @@ jobs:
    - name: Run codespell
      uses: codespell-project/actions-codespell@master
      with:
-        skip: ./ArduinoCore-API,./libraries/ESP8266SdFat,./libraries/Adafruit_TinyUSB_Arduino,./libraries/LittleFS/lib,./tools/pyserial,./pico-sdk,./.github,./docs/i2s.rst,./cores/rp2040/api,./libraries/FreeRTOS,./tools/libbearssl/bearssl,./include,./libraries/WiFi/examples/BearSSL_Server,./ota/uzlib,./libraries/http-parser/lib,./libraries/WebServer/examples/HelloServerBearSSL/HelloServerBearSSL.ino,./libraries/HTTPUpdateServer/examples/SecureBearSSLUpdater/SecureBearSSLUpdater.ino
+        skip: ./ArduinoCore-API,./libraries/ESP8266SdFat,./libraries/Adafruit_TinyUSB_Arduino,./libraries/LittleFS/lib,./tools/pyserial,./pico-sdk,./.github,./docs/i2s.rst,./cores/rp2040/api,./libraries/FreeRTOS,./tools/libbearssl/bearssl,./include,./libraries/WiFi/examples/BearSSL_Server,./ota/uzlib,./libraries/http-parser/lib,./libraries/WebServer/examples/HelloServerBearSSL/HelloServerBearSSL.ino,./libraries/HTTPUpdateServer/examples/SecureBearSSLUpdater/SecureBearSSLUpdater.ino,./.git
        ignore_words_list: ser,dout

 # Consistent style
@@ -46,10 +50,6 @@ jobs:
        ./tests/restyle.sh
        # If anything changed, GIT should return an error and fail the test
        git diff --exit-code
-#    - name: Check Arduino API copy is clean
-#      run: |
-#        git submodule update --init ./ArduinoCore-API
-#        diff -r ./cores/rp2040/api ./ArduinoCore-API/api

 # Build all examples on linux (core and Arduino IDE)
  build-linux:
@@ -62,19 +62,17 @@ jobs:
    - uses: actions/checkout@v3
      with:
        submodules: true
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Cache Linux toolchain
      id: cache-linux
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ./tools/dist
        key: ${{ runner.os }}-${{ hashFiles('package/package_pico_index.template.json', 'tests/common.sh') }}
    - name: Build Sketches
      env:
-        TRAVIS_BUILD_DIR: ${{ github.workspace }}
-        TRAVIS_TAG: ${{ github.ref }}
        BUILD_PARITY: custom
        mod: 6
        rem: ${{ matrix.chunk }}
@@ -92,19 +90,17 @@ jobs:
    - uses: actions/checkout@v3
      with:
        submodules: true
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Cache Linux toolchain
      id: cache-linux
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ./tools/dist
        key: ${{ runner.os }}-${{ hashFiles('package/package_pico_index.template.json', 'tests/common.sh') }}
    - name: Build Sketches
      env:
-        TRAVIS_BUILD_DIR: ${{ github.workspace }}
-        TRAVIS_TAG: ${{ github.ref }}
        BUILD_PARITY: custom
      run: |
        cd pico-sdk
@@ -120,19 +116,17 @@ jobs:
    - uses: actions/checkout@v3
      with:
        submodules: true
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Cache Windows toolchain
      id: cache-windows
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ./tools/dist
        key: ${{ runner.os }}-${{ hashFiles('package/package_pico_index.template.json', 'tests/common.sh') }}
    - name: Build Sketch
      env:
-        TRAVIS_BUILD_DIR: ${{ github.workspace }}
-        TRAVIS_TAG: ${{ github.ref }}
        WINDOWS: 1
        BUILD_PARITY: custom
        mod: 500
@@ -150,24 +144,22 @@ jobs:
 # Single build under macOS to ensure the Mac toolchain is good.
  build-mac:
    name: Mac
-    runs-on: macOS-latest
+    runs-on: macOS-12
    steps:
    - uses: actions/checkout@v3
      with:
        submodules: true
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Cache Mac toolchain
      id: cache-mac
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ./tools/dist
        key: ${{ runner.os }}-${{ hashFiles('package/package_pico_index.template.json', 'tests/common.sh') }}
    - name: Build Sketch
      env:
-        TRAVIS_BUILD_DIR: ${{ github.workspace }}
-        TRAVIS_TAG: ${{ github.ref }}
        MACOSX: 1
        BUILD_PARITY: custom
        mod: 500
@@ -194,19 +186,21 @@ jobs:
        git submodule update --init
        cd ../..
    - name: Cache pip
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.cache/pip
        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
        restore-keys: |
          ${{ runner.os }}-pip-
    - name: Cache PlatformIO
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.platformio
        key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
    - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
+      with:
+        python-version: '3.x'
    - name: Install PlatformIO
      run: |
        python -m pip install --upgrade pip
@@ -9,22 +9,22 @@ jobs:
    name: Update master JSON file
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
      with:
        submodules: true
    - name: Cache pip
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.cache/pip
        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
        restore-keys: |
          ${{ runner.os }}-pip-
    - name: Cache PlatformIO
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.platformio
        key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Install PlatformIO
@@ -15,11 +15,11 @@ jobs:
    name: Package
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
      with:
        submodules: true
        fetch-depth: 0
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v4
      with:
        python-version: '3.x'
    - name: Build package JSON
@@ -12,7 +12,9 @@ See https://arduino-pico.readthedocs.io/en/latest/ along with the examples for m
 # Supported Boards
 * Raspberry Pi Pico
 * Raspberry Pi Pico W
+* 0xCB Helios
 * Adafruit Feather RP2040
+* Adafruit Feather RP2040 SCORPIO
 * Adafruit ItsyBitsy RP2040
 * Adafruit KB2040
 * Adafruit Macropad RP2040
@@ -20,8 +22,10 @@ See https://arduino-pico.readthedocs.io/en/latest/ along with the examples for m
 * Adafruit STEMMA Friend RP2040
 * Adafruit Trinkey RP2040 QT
 * Arduino Nano RP2040 Connect
+* BridgeTek IDM2040-7A
 * Cytron Maker Pi RP2040
 * Cytron Maker Nano RP2040
+* DatanoiseTV PicoADK+
 * DeRuiLab FlyBoard2040 Core
 * DFRobot Beetle RP2040
 * ElectronicCats Hunter Cat NFC
@@ -34,12 +38,22 @@ See https://arduino-pico.readthedocs.io/en/latest/ along with the examples for m
 * Invector Labs Challenger RP2040 SubGHz
 * Invector Labs Challenger RP2040 SD/RTC
 * Invector Labs RPICO32
+* Melopero Cookie RP2040
 * Melopero Shake RP2040
+* nullbits Bit-C PRO
+* Pimoroni PGA2040
 * Seeed XIAO RP2040
 * Solder Party RP2040 Stamp
 * SparkFun ProMicro RP2040
 * SparkFun Thing Plus RP2040
 * uPesy RP2040 DevKit
+* VCC-GND YD-RP2040
+* Viyalab Mizu RP2040
+* Waveshare RP2040 Zero
+* Waveshare RP2040 One
+* Waveshare RP2040 Plus
+* Waveshare RP2040 LCD 0.96
+* Waveshare RP2040 LCD 1.28
 * WIZnet W5100S-EVB-Pico
 * WIZnet W5500-EVB-Pico
 * WIZnet WizFi360-EVB-Pico
@@ -156,6 +170,9 @@ The installed tools include a version of OpenOCD (in the pqt-openocd directory)
 * FreeRTOS SMP support
 * Overclocking and underclocking from the menus
 * digitalWrite/Read, shiftIn/Out, tone, analogWrite(PWM)/Read, temperature
+* Analog stereo audio in using DMA and the built-in ADC
+* Analog stereo audio out using PWM hardware
+* USB drive mode for data loggers (SingleFileDrive)
 * Peripherals:  SPI master, Wire(I2C) master/slave, dual UART, emulated EEPROM, I2S audio input, I2S audio output, Servo
 * printf (i.e. debug) output over USB serial

@@ -0,0 +1,23 @@
+// Padded and checksummed version of: generated\Winbond\W25Q16JVxQ\boot2.bin
+
+.cpu cortex-m0plus
+.thumb
+
+.section .boot2, "ax"
+
+.byte 0xf7, 0xb5, 0x73, 0x46, 0x21, 0x22, 0x02, 0x26, 0x01, 0x93, 0x29, 0x4b, 0xc0, 0x24, 0x5a, 0x60
+.byte 0x9a, 0x68, 0x00, 0x27, 0xb2, 0x43, 0xda, 0x60, 0x9a, 0x60, 0x1a, 0x61, 0x5a, 0x61, 0x04, 0x23
+.byte 0x01, 0x25, 0x64, 0x05, 0xa7, 0x60, 0x63, 0x61, 0x22, 0x4b, 0x30, 0x00, 0x1d, 0x60, 0xe0, 0x23
+.byte 0xdb, 0x02, 0x23, 0x60, 0x35, 0x23, 0xa5, 0x60, 0x23, 0x66, 0x23, 0x66, 0x00, 0xf0, 0x4a, 0xf8
+.byte 0xc0, 0xb2, 0xb0, 0x42, 0x12, 0xd0, 0x06, 0x23, 0x28, 0x00, 0x23, 0x66, 0x00, 0xf0, 0x42, 0xf8
+.byte 0x25, 0x66, 0x03, 0x20, 0x27, 0x66, 0x26, 0x66, 0x00, 0xf0, 0x3c, 0xf8, 0x03, 0x36, 0x26, 0x66
+.byte 0x02, 0x20, 0x26, 0x66, 0x00, 0xf0, 0x36, 0xf8, 0x28, 0x42, 0xf8, 0xd1, 0x00, 0x25, 0x12, 0x4b
+.byte 0xa5, 0x60, 0x12, 0x4f, 0x23, 0x60, 0x12, 0x4b, 0x65, 0x60, 0x01, 0x26, 0x3b, 0x60, 0xeb, 0x23
+.byte 0xa6, 0x60, 0x23, 0x66, 0x4b, 0x3b, 0x23, 0x66, 0x02, 0x20, 0x00, 0xf0, 0x23, 0xf8, 0x0d, 0x4b
+.byte 0xa5, 0x60, 0x3b, 0x60, 0xa6, 0x60, 0x01, 0x9b, 0xab, 0x42, 0x08, 0xd1, 0x0a, 0x4b, 0x0b, 0x4a
+.byte 0x13, 0x60, 0x1b, 0x68, 0x83, 0xf3, 0x08, 0x88, 0x09, 0x4b, 0x1b, 0x68, 0x18, 0x47, 0xf7, 0xbd
+.byte 0x00, 0x00, 0x02, 0x40, 0xf0, 0x00, 0x00, 0x18, 0x00, 0x03, 0x5f, 0x00, 0xf4, 0x00, 0x00, 0x18
+.byte 0x21, 0x22, 0x00, 0x00, 0x22, 0x20, 0x00, 0xa0, 0x00, 0x01, 0x00, 0x10, 0x08, 0xed, 0x00, 0xe0
+.byte 0x04, 0x01, 0x00, 0x10, 0xc0, 0x22, 0x03, 0x00, 0x04, 0x21, 0x52, 0x05, 0x90, 0x6a, 0x08, 0x42
+.byte 0xfc, 0xd0, 0x01, 0x21, 0x90, 0x6a, 0x08, 0x42, 0xfc, 0xd1, 0x01, 0x3b, 0xdb, 0xb2, 0x10, 0x6e
+.byte 0x00, 0x2b, 0xfa, 0xd1, 0x70, 0x47, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xaa, 0xa0, 0xf0, 0x2f
@@ -0,0 +1,23 @@
+// Padded and checksummed version of: boot2_w25q64jv.4.bin
+
+.cpu cortex-m0plus
+.thumb
+
+.section .boot2, "ax"
+
+.byte 0xf7, 0xb5, 0x73, 0x46, 0x21, 0x22, 0x02, 0x25, 0x01, 0x93, 0x29, 0x4b, 0xc0, 0x24, 0x5a, 0x60
+.byte 0x9a, 0x68, 0x01, 0x26, 0xaa, 0x43, 0xda, 0x60, 0x9a, 0x60, 0x1a, 0x61, 0x5a, 0x61, 0x00, 0x23
+.byte 0x64, 0x05, 0xa3, 0x60, 0x04, 0x33, 0x63, 0x61, 0x22, 0x4b, 0x28, 0x00, 0x1e, 0x60, 0xe0, 0x23
+.byte 0xdb, 0x02, 0x23, 0x60, 0x35, 0x23, 0xa6, 0x60, 0x23, 0x66, 0x23, 0x66, 0x00, 0xf0, 0x4a, 0xf8
+.byte 0xc0, 0xb2, 0xa8, 0x42, 0x12, 0xd0, 0x06, 0x23, 0x30, 0x00, 0x23, 0x66, 0x00, 0xf0, 0x42, 0xf8
+.byte 0x31, 0x23, 0x28, 0x00, 0x23, 0x66, 0x25, 0x66, 0x00, 0xf0, 0x3c, 0xf8, 0x03, 0x35, 0x25, 0x66
+.byte 0x02, 0x20, 0x25, 0x66, 0x00, 0xf0, 0x36, 0xf8, 0x30, 0x42, 0xf8, 0xd1, 0x00, 0x25, 0x12, 0x4b
+.byte 0xa5, 0x60, 0x12, 0x4f, 0x23, 0x60, 0x12, 0x4b, 0x65, 0x60, 0x01, 0x26, 0x3b, 0x60, 0xeb, 0x23
+.byte 0xa6, 0x60, 0x23, 0x66, 0x4b, 0x3b, 0x23, 0x66, 0x02, 0x20, 0x00, 0xf0, 0x23, 0xf8, 0x0d, 0x4b
+.byte 0xa5, 0x60, 0x3b, 0x60, 0xa6, 0x60, 0x01, 0x9b, 0xab, 0x42, 0x08, 0xd1, 0x0a, 0x4b, 0x0b, 0x4a
+.byte 0x13, 0x60, 0x1b, 0x68, 0x83, 0xf3, 0x08, 0x88, 0x09, 0x4b, 0x1b, 0x68, 0x18, 0x47, 0xf7, 0xbd
+.byte 0x00, 0x00, 0x02, 0x40, 0xf0, 0x00, 0x00, 0x18, 0x00, 0x03, 0x5f, 0x00, 0xf4, 0x00, 0x00, 0x18
+.byte 0x21, 0x22, 0x00, 0x00, 0x22, 0x20, 0x00, 0xa0, 0x00, 0x01, 0x00, 0x10, 0x08, 0xed, 0x00, 0xe0
+.byte 0x04, 0x01, 0x00, 0x10, 0xc0, 0x23, 0x02, 0x00, 0x04, 0x21, 0x5b, 0x05, 0x98, 0x6a, 0x08, 0x42
+.byte 0xfc, 0xd0, 0x01, 0x21, 0x98, 0x6a, 0x08, 0x42, 0xfc, 0xd1, 0x18, 0x6e, 0x01, 0x2a, 0x00, 0xd0
+.byte 0x18, 0x6e, 0x70, 0x47, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x66, 0x2d, 0x68, 0xca
@@ -68,10 +68,16 @@ void noInterrupts();
 #define portOutputRegister(port)    ((volatile uint32_t*) sio_hw->gpio_out)
 #define portInputRegister(port)     ((volatile uint32_t*) sio_hw->gpio_in)
 #define portModeRegister(port)      ((volatile uint32_t*) sio_hw->gpio_oe)
+#define digitalWriteFast(pin, val)  (val ? sio_hw->gpio_set = (1 << pin) : sio_hw->gpio_clr = (1 << pin))
+#define digitalReadFast(pin)        ((1 << pin) & sio_hw->gpio_in)
+#define sei() interrupts()
+#define cli() noInterrupts()

 // ADC RP2040-specific calls
 void analogReadResolution(int bits);
-float analogReadTemp();  // Returns core temp in Centigrade
+#ifdef __cplusplus
+float analogReadTemp(float vref = 3.3);  // Returns core temp in Centigrade
+#endif

 // PWM RP2040-specific calls
 void analogWriteFreq(uint32_t freq);
@@ -0,0 +1,66 @@
+/*
+    CoreMutex for the Raspberry Pi Pico RP2040
+
+    Implements a deadlock-safe multicore mutex for sharing things like the
+    USB or UARTs.
+
+    Copyright (c) 2021 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "Arduino.h"
+#include "CoreMutex.h"
+
+CoreMutex::CoreMutex(mutex_t *mutex, uint8_t option) {
+    _mutex = mutex;
+    _acquired = false;
+    _option = option;
+    if (__isFreeRTOS) {
+        auto m = __get_freertos_mutex_for_ptr(mutex);
+        if (_option & FromISR) {
+            __freertos_mutex_take_from_isr(m);
+        } else {
+            __freertos_mutex_take(m);
+        }
+    } else {
+        uint32_t owner;
+        if (!mutex_try_enter(_mutex, &owner)) {
+            if (owner == get_core_num()) { // Deadlock!
+                if (_option & DebugEnable) {
+                    DEBUGCORE("CoreMutex - Deadlock detected!\n");
+                }
+                return;
+            }
+            mutex_enter_blocking(_mutex);
+        }
+    }
+    _acquired = true;
+}
+
+CoreMutex::~CoreMutex() {
+    if (_acquired) {
+        if (__isFreeRTOS) {
+            auto m = __get_freertos_mutex_for_ptr(_mutex);
+            if (_option & FromISR) {
+                __freertos_mutex_give_from_isr(m);
+            } else {
+                __freertos_mutex_give(m);
+            }
+        } else {
+            mutex_exit(_mutex);
+        }
+    }
+}
@@ -26,39 +26,15 @@
 #include "pico/mutex.h"
 #include "_freertos.h"

+enum {
+    DebugEnable = 1,
+    FromISR = 1 << 1,
+};
+
 class CoreMutex {
 public:
-    CoreMutex(mutex_t *mutex, bool debugEnable = true) {
-        _mutex = mutex;
-        _acquired = false;
-        if (__isFreeRTOS) {
-            auto m = __get_freertos_mutex_for_ptr(mutex);
-            __freertos_mutex_take(m);
-        } else {
-            uint32_t owner;
-            if (!mutex_try_enter(_mutex, &owner)) {
-                if (owner == get_core_num()) { // Deadlock!
-                    if (debugEnable) {
-                        DEBUGCORE("CoreMutex - Deadlock detected!\n");
-                    }
-                    return;
-                }
-                mutex_enter_blocking(_mutex);
-            }
-        }
-        _acquired = true;
-    }
-
-    ~CoreMutex() {
-        if (_acquired) {
-            if (__isFreeRTOS) {
-                auto m = __get_freertos_mutex_for_ptr(_mutex);
-                __freertos_mutex_give(m);
-            } else {
-                mutex_exit(_mutex);
-            }
-        }
-    }
+    CoreMutex(mutex_t *mutex, uint8_t option = DebugEnable);
+    ~CoreMutex();

    operator bool() {
        return _acquired;
@@ -67,4 +43,5 @@ public:
 private:
    mutex_t *_mutex;
    bool _acquired;
+    u_int8_t _option;
 };
@@ -192,13 +192,12 @@ File File::openNextFile() {
 String File::readString() {
    String ret;
    ret.reserve(size() - position());
-    char temp[256 + 1];
-    int countRead = readBytes(temp, sizeof(temp) - 1);
-    while (countRead > 0) {
-        temp[countRead] = 0;
-        ret += temp;
-        countRead = readBytes(temp, sizeof(temp) - 1);
-    }
+    uint8_t temp[256];
+    int countRead;
+    do {
+        countRead = read(temp, sizeof(temp));
+        ret.concat(temp, countRead);
+    } while (countRead > 0);
    return ret;
 }

@@ -1,10 +1,7 @@
 /*
-    WiFiMutex.h - Ensure the timer-driven sys_check_timeouts doesn't
-                  get executed while we're in the user-level TCP stack.
-    Copyright (c) 2022 Earle F. Philhower, III.  All rights reserved.
+    RP2040 utility class

-    Implements the API defined by the Arduino WiFiNINA library,
-    copyright (c) 2018 Arduino SA. All rights reserved.
+    Copyright (c) 2021 Earle F. Philhower, III <earlephilhower@yahoo.com>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -21,21 +18,16 @@
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

-#pragma once
+#include <Arduino.h>
+#include <hardware/structs/psm.h>

-extern "C" volatile bool __inLWIP;
+extern "C" void boot_double_tap_check();

-class LWIPMutex {
-public:
-    LWIPMutex() {
-        __inLWIP = true;
-        _ref++;
+// The following check will never actually execute, but it will cause the boot reset
+// checker to be linked in as part of the constructors.
+
+void RP2040::enableDoubleResetBootloader() {
+    if (psm_hw->done == 0) {
+        boot_double_tap_check();
    }
-    ~LWIPMutex() {
-        if (0 == --_ref) {
-            __inLWIP = false;
-        }
-    }
-private:
-    static int _ref;
-};
+}
@@ -314,6 +314,8 @@ public:
        reboot();
    }

+    static void enableDoubleResetBootloader();
+
    void wdt_begin(uint32_t delay_ms) {
        watchdog_enable(delay_ms, 1);
    }
@@ -323,7 +325,7 @@ public:
    }

    const char *getChipID() {
-        static char id[PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1] = { 0 };
+        static char id[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1] = { 0 };
        if (!id[0]) {
            pico_get_unique_board_id_string(id, sizeof(id));
        }
@@ -33,6 +33,10 @@
 #include "hardware/irq.h"
 #include "pico/mutex.h"
 #include "pico/unique_id.h"
+#include "pico/usb_reset_interface.h"
+#include "hardware/watchdog.h"
+#include "pico/bootrom.h"
+#include <device/usbd_pvt.h>

 // Big, global USB mutex, shared with all USB devices to make sure we don't
 // have multiple cores updating the TUSB state in parallel
@@ -67,10 +71,18 @@ static int __usb_task_irq;
 #define USBD_STR_PRODUCT (0x02)
 #define USBD_STR_SERIAL (0x03)
 #define USBD_STR_CDC (0x04)
-
+#define USBD_STR_RPI_RESET (0x05)

 #define EPNUM_HID   0x83

+#define USBD_MSC_EPOUT 0x03
+#define USBD_MSC_EPIN 0x84
+#define USBD_MSC_EPSIZE 64
+
+#define TUD_RPI_RESET_DESCRIPTOR(_itfnum, _stridx) \
+  /* Interface */\
+  9, TUSB_DESC_INTERFACE, _itfnum, 0, 0, TUSB_CLASS_VENDOR_SPECIFIC, RESET_INTERFACE_SUBCLASS, RESET_INTERFACE_PROTOCOL, _stridx,
+

 const uint8_t *tud_descriptor_device_cb(void) {
    static tusb_desc_device_t usbd_desc_device = {
@@ -89,7 +101,7 @@ const uint8_t *tud_descriptor_device_cb(void) {
        .iSerialNumber = USBD_STR_SERIAL,
        .bNumConfigurations = 1
    };
-    if (__USBInstallSerial && !__USBInstallKeyboard && !__USBInstallMouse && !__USBInstallJoystick) {
+    if (__USBInstallSerial && !__USBInstallKeyboard && !__USBInstallMouse && !__USBInstallJoystick && !__USBInstallMassStorage) {
        // Can use as-is, this is the default USB case
        return (const uint8_t *)&usbd_desc_device;
    }
@@ -103,6 +115,9 @@ const uint8_t *tud_descriptor_device_cb(void) {
    if (__USBInstallJoystick) {
        usbd_desc_device.idProduct |= 0x0100;
    }
+    if (__USBInstallMassStorage) {
+        usbd_desc_device.idProduct ^= 0x2000;
+    }
    // Set the device class to 0 to indicate multiple device classes
    usbd_desc_device.bDeviceClass = 0;
    usbd_desc_device.bDeviceSubClass = 0;
@@ -223,7 +238,7 @@ void __SetupUSBDescriptor() {
    if (!usbd_desc_cfg) {
        bool hasHID = __USBInstallKeyboard || __USBInstallMouse || __USBInstallJoystick;

-        uint8_t interface_count = (__USBInstallSerial ? 2 : 0) + (hasHID ? 1 : 0);
+        uint8_t interface_count = (__USBInstallSerial ? 2 : 0) + (hasHID ? 1 : 0) + (__USBInstallMassStorage ? 1 : 0);

        uint8_t cdc_desc[TUD_CDC_DESC_LEN] = {
            // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
@@ -238,7 +253,20 @@ void __SetupUSBDescriptor() {
            TUD_HID_DESCRIPTOR(hid_itf, 0, HID_ITF_PROTOCOL_NONE, hid_report_len, EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 10)
        };

-        int usbd_desc_len = TUD_CONFIG_DESC_LEN + (__USBInstallSerial ? sizeof(cdc_desc) : 0) + (hasHID ? sizeof(hid_desc) : 0);
+        uint8_t msd_itf = interface_count - 1;
+        uint8_t msd_desc[TUD_MSC_DESC_LEN] = {
+            TUD_MSC_DESCRIPTOR(msd_itf, 0, USBD_MSC_EPOUT, USBD_MSC_EPIN, USBD_MSC_EPSIZE)
+        };
+
+        int usbd_desc_len = TUD_CONFIG_DESC_LEN + (__USBInstallSerial ? sizeof(cdc_desc) : 0) + (hasHID ? sizeof(hid_desc) : 0) + (__USBInstallMassStorage ? sizeof(msd_desc) : 0);
+
+#ifdef ENABLE_PICOTOOL_USB
+        uint8_t picotool_itf = interface_count++;
+        uint8_t picotool_desc[] = {
+            TUD_RPI_RESET_DESCRIPTOR(picotool_itf, USBD_STR_RPI_RESET)
+        };
+        usbd_desc_len += sizeof(picotool_desc);
+#endif

        uint8_t tud_cfg_desc[TUD_CONFIG_DESC_LEN] = {
            // Config number, interface count, string index, total length, attribute, power in mA
@@ -260,6 +288,14 @@ void __SetupUSBDescriptor() {
                memcpy(ptr, hid_desc, sizeof(hid_desc));
                ptr += sizeof(hid_desc);
            }
+            if (__USBInstallMassStorage) {
+                memcpy(ptr, msd_desc, sizeof(msd_desc));
+                ptr += sizeof(msd_desc);
+            }
+#ifdef ENABLE_PICOTOOL_USB
+            memcpy(ptr, picotool_desc, sizeof(picotool_desc));
+            ptr += sizeof(picotool_desc);
+#endif
        }
    }
 }
@@ -277,6 +313,9 @@ const uint16_t *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
        [USBD_STR_PRODUCT] = "PicoArduino",
        [USBD_STR_SERIAL] = idString,
        [USBD_STR_CDC] = "Board CDC",
+#ifdef ENABLE_PICOTOOL_USB
+        [USBD_STR_RPI_RESET] = "Reset",
+#endif
    };

    if (!idString[0]) {
@@ -367,4 +406,135 @@ extern "C" void tud_hid_set_report_cb(uint8_t instance, uint8_t report_id, hid_r
    (void) bufsize;
 }

+extern "C" int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize) __attribute__((weak));
+extern "C" int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize) {
+    (void) lun;
+    (void) lba;
+    (void) offset;
+    (void) buffer;
+    (void) bufsize;
+    return -1;
+}
+
+extern "C" bool tud_msc_test_unit_ready_cb(uint8_t lun) __attribute__((weak));
+extern "C" bool tud_msc_test_unit_ready_cb(uint8_t lun) {
+    (void) lun;
+    return false;
+}
+
+extern "C" int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize) __attribute__((weak));
+extern "C" int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize) {
+    (void) lun;
+    (void) lba;
+    (void) offset;
+    (void) buffer;
+    (void) bufsize;
+    return -1;
+}
+
+extern "C" int32_t tud_msc_scsi_cb(uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize) __attribute__((weak));
+extern "C" int32_t tud_msc_scsi_cb(uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize) {
+    (void) lun;
+    (void) scsi_cmd;
+    (void) buffer;
+    (void) bufsize;
+    return 0;
+}
+
+extern "C" void tud_msc_capacity_cb(uint8_t lun, uint32_t* block_count, uint16_t* block_size) __attribute__((weak));
+extern "C" void tud_msc_capacity_cb(uint8_t lun, uint32_t* block_count, uint16_t* block_size) {
+    (void) lun;
+    *block_count = 0;
+    *block_size = 0;
+}
+
+extern "C" void tud_msc_inquiry_cb(uint8_t lun, uint8_t vendor_id[8], uint8_t product_id[16], uint8_t product_rev[4]) __attribute__((weak));
+extern "C" void tud_msc_inquiry_cb(uint8_t lun, uint8_t vendor_id[8], uint8_t product_id[16], uint8_t product_rev[4]) {
+    (void) lun;
+    vendor_id[0] = 0;
+    product_id[0] = 0;
+    product_rev[0] = 0;
+}
+
+
+
+#ifdef ENABLE_PICOTOOL_USB
+
+static uint8_t _picotool_itf_num;
+
+static void resetd_init() {
+}
+
+static void resetd_reset(uint8_t rhport) {
+    (void) rhport;
+    _picotool_itf_num = 0;
+}
+
+static uint16_t resetd_open(uint8_t rhport,
+                            tusb_desc_interface_t const *itf_desc, uint16_t max_len) {
+    (void) rhport;
+    TU_VERIFY(TUSB_CLASS_VENDOR_SPECIFIC == itf_desc->bInterfaceClass &&
+              RESET_INTERFACE_SUBCLASS == itf_desc->bInterfaceSubClass &&
+              RESET_INTERFACE_PROTOCOL == itf_desc->bInterfaceProtocol, 0);
+
+    uint16_t const drv_len = sizeof(tusb_desc_interface_t);
+    TU_VERIFY(max_len >= drv_len, 0);
+
+    _picotool_itf_num = itf_desc->bInterfaceNumber;
+    return drv_len;
+}
+
+// Support for parameterized reset via vendor interface control request
+static bool resetd_control_xfer_cb(uint8_t rhport, uint8_t stage,
+                                   tusb_control_request_t const *request) {
+    (void) rhport;
+    // nothing to do with DATA & ACK stage
+    if (stage != CONTROL_STAGE_SETUP) {
+        return true;
+    }
+
+    if (request->wIndex == _picotool_itf_num) {
+        if (request->bRequest == RESET_REQUEST_BOOTSEL) {
+            reset_usb_boot(0, (request->wValue & 0x7f));
+            // does not return, otherwise we'd return true
+        }
+
+        if (request->bRequest == RESET_REQUEST_FLASH) {
+            watchdog_reboot(0, 0, 100);
+            return true;
+        }
+
+    }
+    return false;
+}
+
+static bool resetd_xfer_cb(uint8_t rhport, uint8_t ep_addr,
+                           xfer_result_t result, uint32_t xferred_bytes) {
+    (void) rhport;
+    (void) ep_addr;
+    (void) result;
+    (void) xferred_bytes;
+    return true;
+}
+
+static usbd_class_driver_t const _resetd_driver = {
+#if CFG_TUSB_DEBUG >= 2
+    .name = "RESET",
+#endif
+    .init             = resetd_init,
+    .reset            = resetd_reset,
+    .open             = resetd_open,
+    .control_xfer_cb  = resetd_control_xfer_cb,
+    .xfer_cb          = resetd_xfer_cb,
+    .sof              = NULL
+};
+
+// Implement callback to add our custom driver
+usbd_class_driver_t const *usbd_app_driver_get_cb(uint8_t *driver_count) {
+    *driver_count = 1;
+    return &_resetd_driver;
+}
+#endif
+
+
 #endif
@@ -26,6 +26,7 @@ extern void __USBInstallSerial() __attribute__((weak));
 extern void __USBInstallKeyboard() __attribute__((weak));
 extern void __USBInstallJoystick() __attribute__((weak));
 extern void __USBInstallMouse() __attribute__((weak));
+extern void __USBInstallMassStorage() __attribute__((weak));

 // Big, global USB mutex, shared with all USB devices to make sure we don't
 // have multiple cores updating the TUSB state in parallel
@@ -1,5 +1,5 @@
 #pragma once
 #define ARDUINO_PICO_MAJOR 2
-#define ARDUINO_PICO_MINOR 5
-#define ARDUINO_PICO_REVISION 3
-#define ARDUINO_PICO_VERSION_STR "2.5.3"
+#define ARDUINO_PICO_MINOR 7
+#define ARDUINO_PICO_REVISION 1
+#define ARDUINO_PICO_VERSION_STR "2.7.1"
@@ -230,7 +230,7 @@ void SerialPIO::begin(unsigned long baud, uint16_t config) {
        pio_sm_clear_fifos(_rxPIO, _rxSM); // Remove any existing data

        // Put phase divider into OSR w/o using add'l program memory
-        pio_sm_put_blocking(_rxPIO, _rxSM, clock_get_hz(clk_sys) / (_baud * 2) - 5 /* insns in PIO halfbit loop */);
+        pio_sm_put_blocking(_rxPIO, _rxSM, clock_get_hz(clk_sys) / (_baud * 2) - 7 /* insns in PIO halfbit loop */);
        pio_sm_exec(_rxPIO, _rxSM, pio_encode_pull(false, false));

        // Join the TX FIFO to the RX one now that we don't need it
@@ -259,9 +259,11 @@ void SerialPIO::end() {
    }
    if (_tx != NOPIN) {
        pio_sm_set_enabled(_txPIO, _txSM, false);
+        pio_sm_unclaim(_txPIO, _txSM);
    }
    if (_rx != NOPIN) {
        pio_sm_set_enabled(_rxPIO, _rxSM, false);
+        pio_sm_unclaim(_rxPIO, _rxSM);
        _pioSP[pio_get_index(_rxPIO)][_rxSM] = nullptr;
        // If no more active, disable the IRQ
        auto pioNum = pio_get_index(_rxPIO);
@@ -69,7 +69,7 @@ bool SerialUART::setRTS(pin_size_t pin) {
    constexpr uint32_t valid[2] = { __bitset({3, 15, 19}) /* UART0 */,
                                    __bitset({7, 11, 23, 27})  /* UART1 */
                                  };
-    if ((!_running) && ((1 << pin) & valid[uart_get_index(_uart)])) {
+    if ((!_running) && ((pin == UART_PIN_NOT_DEFINED) || ((1 << pin) & valid[uart_get_index(_uart)]))) {
        _rts = pin;
        return true;
    }
@@ -86,7 +86,7 @@ bool SerialUART::setCTS(pin_size_t pin) {
    constexpr uint32_t valid[2] = { __bitset({2, 14, 18}) /* UART0 */,
                                    __bitset({6, 10, 22, 26})  /* UART1 */
                                  };
-    if ((!_running) && ((1 << pin) & valid[uart_get_index(_uart)])) {
+    if ((!_running) && ((pin == UART_PIN_NOT_DEFINED) || ((1 << pin) & valid[uart_get_index(_uart)]))) {
        _cts = pin;
        return true;
    }
@@ -390,7 +390,12 @@ void __not_in_flash_func(SerialUART::_handleIRQ)(bool inIRQ) {
    // ICR is write-to-clear
    uart_get_hw(_uart)->icr = UART_UARTICR_RTIC_BITS | UART_UARTICR_RXIC_BITS;
    while (uart_is_readable(_uart)) {
-        auto val = uart_getc(_uart);
+        uint32_t raw = uart_get_hw(_uart)->dr;
+        if (raw & 0x700) {
+            // Framing, Parity, or Break.  Ignore this bad char
+            continue;
+        }
+        uint8_t val = raw & 0xff;
        auto next_writer = _writer + 1;
        if (next_writer == _fifoSize) {
            next_writer = 0;
@@ -28,6 +28,7 @@ typedef struct {
    pin_size_t pin;
    PIO pio;
    int sm;
+    int off;
    alarm_id_t alarm;
 } Tone;

@@ -38,10 +39,18 @@ auto_init_mutex(_toneMutex);
 static PIOProgram _tone2Pgm(&tone2_program);
 static std::map<pin_size_t, Tone *> _toneMap;

+static inline bool pio_sm_get_enabled(PIO pio, uint sm) {
+    check_pio_param(pio);
+    check_sm_param(sm);
+    return (pio->ctrl & ~(1u << sm)) & (1 << sm);
+}
+
 int64_t _stopTonePIO(alarm_id_t id, void *user_data) {
    (void) id;
    Tone *tone = (Tone *)user_data;
    tone->alarm = 0;
+    digitalWrite(tone->pin, LOW);
+    pinMode(tone->pin, OUTPUT);
    pio_sm_set_enabled(tone->pio, tone->sm, false);
    return 0;
 }
@@ -72,14 +81,12 @@ void tone(uint8_t pin, unsigned int frequency, unsigned long duration) {
        newTone = new Tone();
        newTone->pin = pin;
        pinMode(pin, OUTPUT);
-        int off;
-        if (!_tone2Pgm.prepare(&newTone->pio, &newTone->sm, &off)) {
+        if (!_tone2Pgm.prepare(&newTone->pio, &newTone->sm, &newTone->off)) {
            DEBUGCORE("ERROR: tone unable to start, out of PIO resources\n");
            // ERROR, no free slots
            delete newTone;
            return;
        }
-        tone2_program_init(newTone->pio, newTone->sm, off, pin);
        newTone->alarm = 0;
    } else {
        newTone = entry->second;
@@ -88,6 +95,9 @@ void tone(uint8_t pin, unsigned int frequency, unsigned long duration) {
            newTone->alarm = 0;
        }
    }
+    if (!pio_sm_get_enabled(newTone->pio, newTone->sm)) {
+        tone2_program_init(newTone->pio, newTone->sm, newTone->off, pin);
+    }
    pio_sm_clear_fifos(newTone->pio, newTone->sm); // Remove any old updates that haven't yet taken effect
    pio_sm_put_blocking(newTone->pio, newTone->sm, RP2040::usToPIOCycles(us));
    pio_sm_set_enabled(newTone->pio, newTone->sm, true);
@@ -99,7 +109,7 @@ void tone(uint8_t pin, unsigned int frequency, unsigned long duration) {
        if (ret > 0) {
            newTone->alarm = ret;
        } else {
-            DEBUGCORE("ERROR: Unable to allocate timer for tone(%d, %d, %d)\n",
+            DEBUGCORE("ERROR: Unable to allocate timer for tone(%d, %d, %lu)\n",
                      pin, frequency, duration);
        }
    }
@@ -0,0 +1 @@
+#include "api/String.h"
@@ -38,10 +38,15 @@ extern "C" SemaphoreHandle_t __get_freertos_mutex_for_ptr(mutex_t *m) {
            return _map[i].dst;
        }
    }
-    // Make a new mutex
-    auto fm = __freertos_mutex_create();
+
    for (int i = 0; i < 16; i++) {
        if (_map[i].src == nullptr) {
+            // Make a new mutex
+            SemaphoreHandle_t fm = __freertos_mutex_create();
+            if (fm == nullptr) {
+                return nullptr;
+            }
+
            _map[i].src = m;
            _map[i].dst = fm;
            return fm;
@@ -41,8 +41,10 @@ extern "C" {
    extern SemaphoreHandle_t _freertos_recursive_mutex_create() __attribute__((weak));

    extern void __freertos_mutex_take(SemaphoreHandle_t mtx) __attribute__((weak));
+    extern void __freertos_mutex_take_from_isr(SemaphoreHandle_t mtx) __attribute__((weak));
    extern int __freertos_mutex_try_take(SemaphoreHandle_t mtx) __attribute__((weak));
    extern void __freertos_mutex_give(SemaphoreHandle_t mtx) __attribute__((weak));
+    extern void __freertos_mutex_give_from_isr(SemaphoreHandle_t mtx) __attribute__((weak));

    extern void __freertos_recursive_mutex_take(SemaphoreHandle_t mtx) __attribute__((weak));
    extern int __freertos_recursive_mutex_try_take(SemaphoreHandle_t mtx) __attribute__((weak));
@@ -0,0 +1,326 @@
+/*
+    LWIP wrappers to protect against timer-based re-entrancy
+
+    Copyright (c) 202s Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "pico/mutex.h"
+#include "lwip/pbuf.h"
+#include "lwip/udp.h"
+#include "lwip/tcp.h"
+#include "lwip/dns.h"
+#include "lwip/raw.h"
+#include "lwip/timeouts.h"
+
+// Global indicator that we're inside an LWIP block
+extern "C" {
+    volatile bool __inLWIP = false;
+}
+
+auto_init_recursive_mutex(__mtxLWIP);
+
+class LWIPMutex {
+public:
+    LWIPMutex() {
+        noInterrupts();
+        recursive_mutex_enter_blocking(&__mtxLWIP);
+        __inLWIP = true;
+        _ref++;
+        interrupts();
+    }
+
+    ~LWIPMutex() {
+        noInterrupts();
+        if (0 == --_ref) {
+            __inLWIP = false;
+        }
+        recursive_mutex_exit(&__mtxLWIP);
+        interrupts();
+    }
+
+private:
+    static int _ref;
+};
+int LWIPMutex::_ref = 0;
+
+
+extern "C" {
+
+    extern u8_t __real_pbuf_header(struct pbuf *p, s16_t header_size);
+    u8_t __wrap_pbuf_header(struct pbuf *p, s16_t header_size) {
+        LWIPMutex m;
+        return __real_pbuf_header(p, header_size);
+    }
+
+    extern u8_t __real_pbuf_free(struct pbuf *p);
+    u8_t __wrap_pbuf_free(struct pbuf *p) {
+        LWIPMutex m;
+        return __real_pbuf_free(p);
+    }
+
+    extern struct pbuf *__real_pbuf_alloc(pbuf_layer l, u16_t length, pbuf_type type);
+    struct pbuf *__wrap_pbuf_alloc(pbuf_layer l, u16_t length, pbuf_type type) {
+        LWIPMutex m;
+        return __real_pbuf_alloc(l, length, type);
+    }
+
+    extern err_t __real_pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
+    err_t __wrap_pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len) {
+        LWIPMutex m;
+        return __real_pbuf_take(buf, dataptr, len);
+    }
+
+    extern u16_t __real_pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
+    u16_t __wrap_pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset) {
+        LWIPMutex m;
+        return __real_pbuf_copy_partial(p, dataptr, len, offset);
+    }
+
+    extern void __real_pbuf_ref(struct pbuf *p);
+    void __wrap_pbuf_ref(struct pbuf *p) {
+        LWIPMutex m;
+        __real_pbuf_ref(p);
+    }
+
+    extern u8_t __real_pbuf_get_at(const struct pbuf* p, u16_t offset);
+    u8_t __wrap_pbuf_get_at(const struct pbuf* p, u16_t offset) {
+        LWIPMutex m;
+        return __real_pbuf_get_at(p, offset);
+    }
+
+    extern void *__real_pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset);
+    void *__wrap_pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset) {
+        LWIPMutex m;
+        return __real_pbuf_get_contiguous(p, buffer, bufsize, len, offset);
+    }
+
+    extern void __real_pbuf_cat(struct pbuf *head, struct pbuf *tail);
+    void __wrap_pbuf_cat(struct pbuf *head, struct pbuf *tail) {
+        LWIPMutex m;
+        __real_pbuf_cat(head, tail);
+    }
+
+    extern void __real_tcp_arg(struct tcp_pcb *pcb, void *arg);
+    void __wrap_tcp_arg(struct tcp_pcb *pcb, void *arg) {
+        LWIPMutex m;
+        __real_tcp_arg(pcb, arg);
+    }
+
+    extern struct tcp_pcb *__real_tcp_new(void);
+    struct tcp_pcb *__wrap_tcp_new(void) {
+        LWIPMutex m;
+        return __real_tcp_new();
+    }
+
+    extern err_t __real_tcp_bind(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port);
+    err_t __wrap_tcp_bind(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port) {
+        LWIPMutex m;
+        return __real_tcp_bind(pcb, ipaddr, port);
+    }
+
+    extern struct tcp_pcb *__real_tcp_listen(struct tcp_pcb *pcb);
+    struct tcp_pcb *__wrap_tcp_listen(struct tcp_pcb *pcb) {
+        LWIPMutex m;
+        return __real_tcp_listen(pcb);
+    }
+
+    extern struct tcp_pcb *__real_tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
+    struct tcp_pcb *__wrap_tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog) {
+        LWIPMutex m;
+        return __real_tcp_listen_with_backlog(pcb, backlog);
+    }
+
+    extern void __real_tcp_accept(struct tcp_pcb *pcb, err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err));
+    void __wrap_tcp_accept(struct tcp_pcb *pcb, err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err)) {
+        LWIPMutex m;
+        __real_tcp_accept(pcb, accept);
+    }
+
+    extern err_t __real_tcp_connect(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port, err_t (* connected)(void *arg, struct tcp_pcb *tpcb, err_t err));
+    err_t __wrap_tcp_connect(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port, err_t (* connected)(void *arg, struct tcp_pcb *tpcb, err_t err)) {
+        LWIPMutex m;
+        return __real_tcp_connect(pcb, ipaddr, port, connected);
+    }
+
+    extern err_t __real_tcp_write(struct tcp_pcb *pcb, const void *dataptr, u16_t len, u8_t apiflags);
+    err_t __wrap_tcp_write(struct tcp_pcb *pcb, const void *dataptr, u16_t len, u8_t apiflags) {
+        LWIPMutex m;
+        return __real_tcp_write(pcb, dataptr, len, apiflags);
+    }
+
+    extern void __real_tcp_sent(struct tcp_pcb *pcb, err_t (* sent)(void *arg, struct tcp_pcb *tpcb, u16_t len));
+    void __wrap_tcp_sent(struct tcp_pcb *pcb, err_t (* sent)(void *arg, struct tcp_pcb *tpcb, u16_t len)) {
+        LWIPMutex m;
+        __real_tcp_sent(pcb, sent);
+    }
+
+    extern void __real_tcp_recv(struct tcp_pcb *pcb, err_t (* recv)(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err));
+    void __wrap_tcp_recv(struct tcp_pcb *pcb, err_t (* recv)(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)) {
+        LWIPMutex m;
+        __real_tcp_recv(pcb, recv);
+    }
+
+    extern void __real_tcp_recved(struct tcp_pcb *pcb, u16_t len);
+    void __wrap_tcp_recved(struct tcp_pcb *pcb, u16_t len) {
+        LWIPMutex m;
+        __real_tcp_recved(pcb, len);
+    }
+
+    extern void __real_tcp_poll(struct tcp_pcb *pcb, err_t (* poll)(void *arg, struct tcp_pcb *tpcb), u8_t interval);
+    void __wrap_tcp_poll(struct tcp_pcb *pcb, err_t (* poll)(void *arg, struct tcp_pcb *tpcb), u8_t interval) {
+        LWIPMutex m;
+        __real_tcp_poll(pcb, poll, interval);
+    }
+
+    extern err_t __real_tcp_close(struct tcp_pcb *pcb);
+    err_t __wrap_tcp_close(struct tcp_pcb *pcb) {
+        LWIPMutex m;
+        return __real_tcp_close(pcb);
+    }
+
+    extern void __real_tcp_abort(struct tcp_pcb *pcb);
+    void __wrap_tcp_abort(struct tcp_pcb *pcb) {
+        LWIPMutex m;
+        __real_tcp_abort(pcb);
+    }
+
+    extern void __real_tcp_err(struct tcp_pcb *pcb, void (* err)(void *arg, err_t err));
+    void __wrap_tcp_err(struct tcp_pcb *pcb, void (* err)(void *arg, err_t err)) {
+        LWIPMutex m;
+        __real_tcp_err(pcb, err);
+    }
+
+    extern err_t __real_tcp_output(struct tcp_pcb *pcb);
+    err_t __wrap_tcp_output(struct tcp_pcb *pcb) {
+        LWIPMutex m;
+        return __real_tcp_output(pcb);
+    }
+
+    extern void __real_tcp_setprio(struct tcp_pcb *pcb, u8_t prio);
+    void __wrap_tcp_setprio(struct tcp_pcb *pcb, u8_t prio) {
+        LWIPMutex m;
+        return __real_tcp_setprio(pcb, prio);
+    }
+
+    extern void __real_tcp_backlog_delayed(struct tcp_pcb* pcb);
+    void __wrap_tcp_backlog_delayed(struct tcp_pcb* pcb) {
+        LWIPMutex m;
+        return __real_tcp_backlog_delayed(pcb);
+    }
+
+    extern void __real_tcp_backlog_accepted(struct tcp_pcb* pcb);
+    void __wrap_tcp_backlog_accepted(struct tcp_pcb* pcb) {
+        LWIPMutex m;
+        return __real_tcp_backlog_accepted(pcb);
+    }
+    extern struct udp_pcb *__real_udp_new(void);
+    struct udp_pcb *__wrap_udp_new(void) {
+        LWIPMutex m;
+        return __real_udp_new();
+    }
+
+    extern void __real_udp_remove(struct udp_pcb *pcb);
+    void __wrap_udp_remove(struct udp_pcb *pcb) {
+        LWIPMutex m;
+        __real_udp_remove(pcb);
+    }
+
+    extern err_t __real_udp_bind(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port);
+    err_t __wrap_udp_bind(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port) {
+        LWIPMutex m;
+        return __real_udp_bind(pcb, ipaddr, port);
+    }
+
+    extern err_t __real_udp_connect(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port);
+    err_t __wrap_udp_connect(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port) {
+        LWIPMutex m;
+        return __real_udp_connect(pcb, ipaddr, port);
+    }
+
+    extern err_t __real_udp_disconnect(struct udp_pcb *pcb);
+    err_t __wrap_udp_disconnect(struct udp_pcb *pcb) {
+        LWIPMutex m;
+        return __real_udp_disconnect(pcb);
+    }
+
+    extern err_t __real_udp_send(struct udp_pcb *pcb, struct pbuf *p);
+    err_t __wrap_udp_send(struct udp_pcb *pcb, struct pbuf *p) {
+        LWIPMutex m;
+        return __real_udp_send(pcb, p);
+    }
+
+    extern void __real_udp_recv(struct udp_pcb *pcb, void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p, ip_addr_t *addr, u16_t port), void *recv_arg);
+    void __wrap_udp_recv(struct udp_pcb *pcb, void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p, ip_addr_t *addr, u16_t port), void *recv_arg) {
+        LWIPMutex m;
+        __real_udp_recv(pcb, recv, recv_arg);
+    }
+
+    extern err_t __real_udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif);
+    err_t __wrap_udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif) {
+        LWIPMutex m;
+        return __real_udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
+    }
+
+    extern void __real_sys_check_timeouts(void);
+    void __wrap_sys_check_timeouts(void) {
+        LWIPMutex m;
+        __real_sys_check_timeouts();
+    }
+
+    extern err_t __real_dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found, void *callback_arg);
+    err_t __wrap_dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback found, void *callback_arg) {
+        LWIPMutex m;
+        return __real_dns_gethostbyname(hostname, addr, found, callback_arg);
+    }
+
+    extern err_t __real_dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *addr, dns_found_callback found, void *callback_arg, u8_t dns_addrtype);
+    err_t __wrap_dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *addr, dns_found_callback found, void *callback_arg, u8_t dns_addrtype) {
+        LWIPMutex m;
+        return __real_dns_gethostbyname_addrtype(hostname, addr, found, callback_arg, dns_addrtype);
+    }
+
+    extern struct raw_pcb *__real_raw_new(u8_t proto);
+    struct raw_pcb *__wrap_raw_new(u8_t proto) {
+        LWIPMutex m;
+        return __real_raw_new(proto);
+    }
+
+    extern void __real_raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg);
+    void __wrap_raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg) {
+        LWIPMutex m;
+        __real_raw_recv(pcb, recv, recv_arg);
+    }
+
+    extern err_t __real_raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr);
+    err_t __wrap_raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr) {
+        LWIPMutex m;
+        return __real_raw_bind(pcb, ipaddr);
+    }
+
+    extern err_t __real_raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr);
+    err_t __wrap_raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr) {
+        LWIPMutex m;
+        return __real_raw_sendto(pcb, p, ipaddr);
+    }
+
+    extern void __real_raw_remove(struct raw_pcb *pcb);
+    void __wrap_raw_remove(struct raw_pcb *pcb) {
+        LWIPMutex m;
+        __real_raw_remove(pcb);
+    }
+
+}; // extern "C"
@@ -22,7 +22,6 @@
 #include "RP2040USB.h"
 #include <pico/stdlib.h>
 #include <pico/multicore.h>
-#include "LWIPMutex.h"
 #include <reent.h>

 RP2040 rp2040;
@@ -33,8 +32,6 @@ extern "C" {

 mutex_t _pioMutex;

-int LWIPMutex::_ref = 0;
-
 extern void setup();
 extern void loop();

@@ -128,7 +125,6 @@ extern "C" int main() {
    }
 #endif

-#ifndef NO_USB
    if (!__isFreeRTOS) {
        if (setup1 || loop1) {
            rp2040.fifo.begin(2);
@@ -137,7 +133,6 @@ extern "C" int main() {
        }
        rp2040.fifo.registerCore();
    }
-#endif

    if (!__isFreeRTOS) {
        if (setup1 || loop1) {
@@ -0,0 +1,53 @@
+/*
+    Malloc/etc. interrupt locking wrappers
+
+    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <Arduino.h>
+
+extern "C" void *__real_malloc(size_t size);
+extern "C" void *__real_calloc(size_t count, size_t size);
+extern "C" void *__real_realloc(void *mem, size_t size);
+extern "C" void __real_free(void *mem);
+
+extern "C" void *__wrap_malloc(size_t size) {
+    noInterrupts();
+    void *rc = __real_malloc(size);
+    interrupts();
+    return rc;
+}
+
+extern "C" void *__wrap_calloc(size_t count, size_t size) {
+    noInterrupts();
+    void *rc = __real_calloc(count, size);
+    interrupts();
+    return rc;
+}
+
+extern "C" void *__wrap_realloc(void *mem, size_t size) {
+    noInterrupts();
+    void *rc = __real_realloc(mem, size);
+    interrupts();
+    return rc;
+}
+
+extern "C" void __wrap_free(void *mem) {
+    noInterrupts();
+    __real_free(mem);
+    interrupts();
+}
@@ -6,7 +6,7 @@

 // Taken from the Pico-SDK v1.4.0 and hacked by EFP3 to allow overriding the LWIP setup

-#include <stdio.h>
+//#include <stdio.h>

 #include "pico/cyw43_arch.h"
 #include "pico/mutex.h"
@@ -36,7 +36,7 @@
 #define CYW43_WL_GPIO_LED_PIN 0
 #endif

-volatile bool __inLWIP = false;
+extern volatile bool __inLWIP;

 // note same code
 #if PICO_CYW43_ARCH_THREADSAFE_BACKGROUND
@@ -145,7 +145,7 @@ static void gpio_irq_handler(void) {
 static void low_priority_irq_handler(void) {
    assert(cyw43_core_num == get_core_num());
    if (recursive_mutex_try_enter(&cyw43_mutex, NULL)) {
-        if (recursive_mutex_enter_count(&cyw43_mutex) != 1) {
+        if (__inLWIP || (recursive_mutex_enter_count(&cyw43_mutex) != 1)) {
            low_priority_irq_missed = true;
            CYW43_STAT_INC(PENDSV_DISABLED_COUNT);
        } else {
@@ -0,0 +1,90 @@
+/*
+    Copyright (c) 2021 Raspberry Pi (Trading) Ltd.
+
+    Hacked by EFP3 to allow disabling unless requested
+
+    SPDX-License-Identifier: BSD-3-Clause
+*/
+
+#include "pico.h"
+#include "pico/time.h"
+#include "pico/bootrom.h"
+#include "pico/binary_info.h"
+
+// PICO_CONFIG: PICO_BOOTSEL_VIA_DOUBLE_RESET_TIMEOUT_MS, Window of opportunity for a second press of a reset button to enter BOOTSEL mode (milliseconds), type=int, default=200, group=pico_bootsel_via_double_reset
+#ifndef PICO_BOOTSEL_VIA_DOUBLE_RESET_TIMEOUT_MS
+#define PICO_BOOTSEL_VIA_DOUBLE_RESET_TIMEOUT_MS 350
+#endif
+
+// PICO_CONFIG: PICO_BOOTSEL_VIA_DOUBLE_RESET_ACTIVITY_LED, Optionally define a pin to use as bootloader activity LED when BOOTSEL mode is entered via reset double tap, type=int, min=0, max=29, group=pico_bootsel_via_double_reset
+
+// PICO_CONFIG: PICO_BOOTSEL_VIA_DOUBLE_RESET_INTERFACE_DISABLE_MASK, Optionally disable either the mass storage interface (bit 0) or the PICOBOOT interface (bit 1) when entering BOOTSEL mode via double reset, type=int, min=0, max=3, default=0, group=pico_bootsel_via_double_reset
+#ifndef PICO_BOOTSEL_VIA_DOUBLE_RESET_INTERFACE_DISABLE_MASK
+#define PICO_BOOTSEL_VIA_DOUBLE_RESET_INTERFACE_DISABLE_MASK 0u
+#endif
+
+/** \defgroup pico_bootsel_via_double_reset pico_bootsel_via_double_reset
+
+    When the 'pico_bootsel_via_double_reset' library is linked, a function is
+    injected before main() which will detect when the system has been reset
+    twice in quick succession, and enter the USB ROM bootloader (BOOTSEL mode)
+    when this happens. This allows a double tap of a reset button on a
+    development board to be used to enter the ROM bootloader, provided this
+    library is always linked.
+*/
+
+#if !PICO_NO_BI_BOOTSEL_VIA_DOUBLE_RESET
+bi_decl(bi_program_feature("double reset -> BOOTSEL"));
+#endif
+
+// Doesn't make any sense for a RAM only binary
+#if !PICO_NO_FLASH
+static const uint32_t magic_token[] = {
+    0xf01681de, 0xbd729b29, 0xd359be7a,
+};
+
+// Place our marker on the 2nd core's stack...which will not have been touched when this code is executing
+static uint32_t *magic_location = (uint32_t*)0x20040000;
+//static uint32_t __uninitialized_ram(magic_location)[count_of(magic_token)];
+
+/*  Check for double reset and enter BOOTSEL mode if detected
+
+    This function is registered to run automatically before main(). The
+    algorithm is:
+
+     1. Check for magic token in memory; enter BOOTSEL mode if found.
+     2. Initialise that memory with that magic token.
+     3. Do nothing for a short while (few hundred ms).
+     4. Clear the magic token.
+     5. Continue with normal boot.
+
+    Resetting the device twice quickly will interrupt step 3, leaving the token
+    in place so that the second boot will go to the bootloader.
+*/
+
+/*static*/ void __attribute__((constructor)) boot_double_tap_check(void) {
+    for (uint i = 0; i < count_of(magic_token); i++) {
+        if (magic_location[i] != magic_token[i]) {
+            // Arm, wait, then disarm and continue booting
+            for (i = 0; i < count_of(magic_token); i++) {
+                magic_location[i] = magic_token[i];
+            }
+            busy_wait_us(PICO_BOOTSEL_VIA_DOUBLE_RESET_TIMEOUT_MS * 1000);
+            magic_location[0] = 0;
+            return;
+        }
+    }
+    // Detected a double reset, so enter USB bootloader
+    magic_location[0] = 0;
+#ifdef PICO_BOOTSEL_VIA_DOUBLE_RESET_ACTIVITY_LED
+    const uint32_t led_mask = 1u << PICO_BOOTSEL_VIA_DOUBLE_RESET_ACTIVITY_LED;
+#else
+    const uint32_t led_mask = 0u;
+#endif
+    reset_usb_boot(
+        led_mask,
+        PICO_BOOTSEL_VIA_DOUBLE_RESET_INTERFACE_DISABLE_MASK
+    );
+}
+
+#endif
@@ -26,9 +26,12 @@
 #include <hardware/pll.h>
 #include <hardware/adc.h>

+void __clearADCPin(pin_size_t p);
+
 static uint32_t analogScale = 255;
 static uint32_t analogFreq = 1000;
-static bool pwmInitted = false;
+static uint32_t pwmInitted = 0;
+static bool scaleInitted = false;
 static bool adcInitted = false;
 static uint16_t analogWritePseudoScale = 1;
 static uint16_t analogWriteSlowScale = 1;
@@ -40,31 +43,33 @@ extern "C" void analogWriteFreq(uint32_t freq) {
        return;
    }
    if (freq < 100) {
-        DEBUGCORE("ERROR: analogWriteFreq too low (%d)\n", freq);
+        DEBUGCORE("ERROR: analogWriteFreq too low (%lu)\n", freq);
        analogFreq = 100;
-    } else if (freq > 1'000'000) {
-        DEBUGCORE("ERROR: analogWriteFreq too high (%d)\n", freq);
-        analogFreq = 1'000'000;
+    } else if (freq > 10'000'000) {
+        DEBUGCORE("ERROR: analogWriteFreq too high (%lu)\n", freq);
+        analogFreq = 10'000'000;
    } else {
        analogFreq = freq;
    }
-    pwmInitted = false;
+    pwmInitted = 0;
+    scaleInitted = false;
 }

 extern "C" void analogWriteRange(uint32_t range) {
    if (range == analogScale) {
        return;
    }
-    if ((range >= 15) && (range <= 65535)) {
+    if ((range >= 3) && (range <= 65535)) {
        analogScale = range;
-        pwmInitted = false;
+        pwmInitted = 0;
+        scaleInitted = false;
    } else {
-        DEBUGCORE("ERROR: analogWriteRange out of range (%d)\n", range);
+        DEBUGCORE("ERROR: analogWriteRange out of range (%lu)\n", range);
    }
 }

 extern "C" void analogWriteResolution(int res) {
-    if ((res >= 4) && (res <= 16)) {
+    if ((res >= 2) && (res <= 16)) {
        analogWriteRange((1 << res) - 1);
    } else {
        DEBUGCORE("ERROR: analogWriteResolution out of range (%d)\n", res);
@@ -78,29 +83,30 @@ extern "C" void analogWrite(pin_size_t pin, int val) {
        DEBUGCORE("ERROR: Illegal analogWrite pin (%d)\n", pin);
        return;
    }
-    if (!pwmInitted) {
+    __clearADCPin(pin);
+    if (!scaleInitted) {
        // For low frequencies, we need to scale the output max value up to achieve lower periods
        analogWritePseudoScale = 1;
-        while (((clock_get_hz(clk_sys) / (float)(analogScale * analogFreq)) > 255.0) && (analogScale < 32678)) {
+        while (((clock_get_hz(clk_sys) / ((float)analogScale * analogFreq)) > 255.0) && (analogScale < 32678)) {
            analogWritePseudoScale++;
            analogScale *= 2;
-            DEBUGCORE("Adjusting analogWrite values PS=%d, scale=%d\n", analogWritePseudoScale, analogScale);
+            DEBUGCORE("Adjusting analogWrite values PS=%d, scale=%lu\n", analogWritePseudoScale, analogScale);
        }
        // For high frequencies, we need to scale the output max value down to actually hit the frequency target
        analogWriteSlowScale = 1;
-        while (((clock_get_hz(clk_sys) / (float)(analogScale * analogFreq)) < 2.0) && (analogScale > 32)) {
+        while (((clock_get_hz(clk_sys) / ((float)analogScale * analogFreq)) < 1.0) && (analogScale >= 6)) {
            analogWriteSlowScale++;
            analogScale /= 2;
-            DEBUGCORE("Adjusting analogWrite values SS=%d, scale=%d\n", analogWriteSlowScale, analogScale);
+            DEBUGCORE("Adjusting analogWrite values SS=%d, scale=%lu\n", analogWriteSlowScale, analogScale);
        }
-
+        scaleInitted = true;
+    }
+    if (!(pwmInitted & (1 << pwm_gpio_to_slice_num(pin)))) {
        pwm_config c = pwm_get_default_config();
-        pwm_config_set_clkdiv(&c, clock_get_hz(clk_sys) / (float)(analogScale * analogFreq));
-        pwm_config_set_wrap(&c, analogScale);
-        for (int i = 0; i < 30; i++) {
-            pwm_init(pwm_gpio_to_slice_num(i), &c, true);
-        }
-        pwmInitted = true;
+        pwm_config_set_clkdiv(&c, clock_get_hz(clk_sys) / ((float)analogScale * analogFreq));
+        pwm_config_set_wrap(&c, analogScale - 1);
+        pwm_init(pwm_gpio_to_slice_num(pin), &c, true);
+        pwmInitted |= 1 << pwm_gpio_to_slice_num(pin);
    }

    val <<= analogWritePseudoScale;
@@ -117,7 +123,13 @@ extern "C" void analogWrite(pin_size_t pin, int val) {
 }

 auto_init_mutex(_adcMutex);
-static int _readBits = 10;
+static uint8_t _readBits = 10;
+static uint8_t _lastADCMux = 0;
+static uint32_t _adcGPIOInit = 0;
+
+void __clearADCPin(pin_size_t p) {
+    _adcGPIOInit &= ~(1 << p);
+}

 extern "C" int analogRead(pin_size_t pin) {
    CoreMutex m(&_adcMutex);
@@ -133,12 +145,18 @@ extern "C" int analogRead(pin_size_t pin) {
        adc_init();
        adcInitted = true;
    }
-    adc_gpio_init(pin);
-    adc_select_input(pin - minPin);
+    if (!(_adcGPIOInit & (1 << pin))) {
+        adc_gpio_init(pin);
+        _adcGPIOInit |= 1 << pin;
+    }
+    if (_lastADCMux != pin) {
+        adc_select_input(pin - minPin);
+        _lastADCMux = pin;
+    }
    return (_readBits < 12) ? adc_read() >> (12 - _readBits) : adc_read() << (_readBits - 12);
 }

-extern "C" float analogReadTemp() {
+extern "C" float analogReadTemp(float vref) {
    CoreMutex m(&_adcMutex);

    if (!m) {
@@ -148,12 +166,13 @@ extern "C" float analogReadTemp() {
        adc_init();
        adcInitted = true;
    }
+    _lastADCMux = 0;
    adc_set_temp_sensor_enabled(true);
    delay(1); // Allow things to settle.  Without this, readings can be erratic
    adc_select_input(4); // Temperature sensor
    int v = adc_read();
    adc_set_temp_sensor_enabled(false);
-    float t = 27.0f - ((v * 3.3f / 4096.0f) - 0.706f) / 0.001721f; // From the datasheet
+    float t = 27.0f - ((v * vref / 4096.0f) - 0.706f) / 0.001721f; // From the datasheet
    return t;
 }

@@ -21,6 +21,8 @@
 #include "Arduino.h"
 #include <hardware/gpio.h>

+extern void __clearADCPin(pin_size_t p);
+
 static PinMode _pm[30];

 extern "C" void pinMode(pin_size_t ulPin, PinMode ulMode) __attribute__((weak, alias("__pinMode")));
@@ -75,6 +77,10 @@ extern "C" void __pinMode(pin_size_t ulPin, PinMode ulMode) {
        return;
    }
    _pm[ulPin] = ulMode;
+
+    if ((ulPin >= std::min(A0, A3)) && (ulPin <= std::max(A0, A3))) {
+        __clearADCPin(ulPin);
+    }
 }

 extern "C" void digitalWrite(pin_size_t ulPin, PinStatus ulVal) __attribute__((weak, alias("__digitalWrite")));
@@ -22,24 +22,30 @@
 #include <CoreMutex.h>
 #include <hardware/gpio.h>
 #include <hardware/sync.h>
-#include <stack>
 #include <map>

 // Support nested IRQ disable/re-enable
-static std::stack<uint32_t> _irqStack[2];
+#define maxIRQs 15
+static uint32_t _irqStackTop[2] = { 0, 0 };
+static uint32_t _irqStack[2][maxIRQs];

 extern "C" void interrupts() {
-    if (_irqStack[get_core_num()].empty()) {
+    auto core = get_core_num();
+    if (!_irqStackTop[core]) {
        // ERROR
        return;
    }
-    auto oldIrqs = _irqStack[get_core_num()].top();
-    _irqStack[get_core_num()].pop();
-    restore_interrupts(oldIrqs);
+    restore_interrupts(_irqStack[core][--_irqStackTop[core]]);
 }

 extern "C" void noInterrupts() {
-    _irqStack[get_core_num()].push(save_and_disable_interrupts());
+    auto core = get_core_num();
+    if (_irqStackTop[core] == maxIRQs) {
+        // ERROR
+        panic("IRQ stack overflow");
+    }
+
+    _irqStack[core][_irqStackTop[core]++] = save_and_disable_interrupts();
 }

 // Only 1 GPIO IRQ callback for all pins, so we need to look at the pin it's for and
@@ -71,7 +77,7 @@ static std::map<pin_size_t, CBInfo> _map;
 void _gpioInterruptDispatcher(uint gpio, uint32_t events) {
    (void) events;
    // Only need to lock around the std::map check, not the whole IRQ callback
-    CoreMutex m(&_irqMutex);
+    CoreMutex m(&_irqMutex, (FromISR | DebugEnable));
    if (m) {
        auto irq = _map.find(gpio);
        if (irq != _map.end()) {
@@ -81,6 +87,15 @@ void _gpioInterruptDispatcher(uint gpio, uint32_t events) {
    }
 }

+// To be called when appropriately protected w/IRQ and mutex protects
+static void _detachInterruptInternal(pin_size_t pin) {
+    auto irq = _map.find(pin);
+    if (irq != _map.end()) {
+        gpio_set_irq_enabled(pin, 0x0f /* all */, false);
+        _map.erase(pin);
+    }
+}
+
 extern "C" void attachInterrupt(pin_size_t pin, voidFuncPtr callback, PinStatus mode) {
    CoreMutex m(&_irqMutex);
    if (!m) {
@@ -97,7 +112,7 @@ extern "C" void attachInterrupt(pin_size_t pin, voidFuncPtr callback, PinStatus
    default:      return;  // ERROR
    }
    noInterrupts();
-    detachInterrupt(pin);
+    _detachInterruptInternal(pin);
    CBInfo cb(callback);
    _map.insert({pin, cb});
    gpio_set_irq_enabled_with_callback(pin, events, true, _gpioInterruptDispatcher);
@@ -120,7 +135,7 @@ void attachInterruptParam(pin_size_t pin, voidFuncPtrParam callback, PinStatus m
    default:      return;  // ERROR
    }
    noInterrupts();
-    detachInterrupt(pin);
+    _detachInterruptInternal(pin);
    CBInfo cb(callback, param);
    _map.insert({pin, cb});
    gpio_set_irq_enabled_with_callback(pin, events, true, _gpioInterruptDispatcher);
@@ -134,10 +149,6 @@ extern "C" void detachInterrupt(pin_size_t pin) {
    }

    noInterrupts();
-    auto irq = _map.find(pin);
-    if (irq != _map.end()) {
-        gpio_set_irq_enabled(pin, 0x0f /* all */, false);
-        _map.erase(pin);
-    }
+    _detachInterruptInternal(pin);
    interrupts();
 }
@@ -0,0 +1,87 @@
+ADC Input Library
+=================
+
+The ADC pins can be sampled and recorded by an application using the same
+interface as the I2S or PWM Audio libraries.  This allows analog devices which
+need to be periodically sampled to be read by applications, easily, such as:
+
+* Analog electret microphones
+
+* Potentiometers
+
+* Light dependent resistors (LDR), etc.
+
+
+Up to 4 analog samples can be recorded by the hardware (``A0`` ... ``A4``), and all
+recording is done at 16-bit levels (but be aware that the ADC in the Pico will only
+ever return values between 0...4095).
+
+The interface for the ``ADCInput`` device is very similar to the ``I2S`` input
+device, and most code can be ported simply by instantiating a ``ADCInput``
+object in lieu of an ``I2S`` input object and choosing the pins to record.
+
+Since this uses the ADC hardware, no ``analogRead`` or ``analogReadTemp`` calls are
+allowed while in use.
+
+ADC Input API
+-------------
+
+ADCInput(pin0 [, pin1, pin2, pin3])
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Creates an ADC input object which will record the pins specified in the code.
+Only pins ``A0`` ... ``A4`` can be used, and they must be specified in increasing
+order (i.e. ``ADCInput(A0, A1);`` is valid, but ``ADCInput(A1, A0)`` is not.
+
+bool setBuffers(size_t buffers, size_t bufferWords)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Set the number of DMA buffers and their size in 32-bit words.  Call before
+``ADCInput::begin()``.
+
+When running at high sample rates, it is recommended to increase the
+``bufferWords`` to 32 or higher (i.e. ``adcinput.setBuffers(4, 32);`` ).
+
+bool setPins(pin_size_t pin [, pin1, pin2, pin3])
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adjusts the pin to record.  Only legal before ``ADCInput::begin()``.
+
+bool setFrequency(long sampleRate)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Sets the ADC sampling frequency, but does not start recording (however if the
+device was already running, it will wontinue to run at the new frequency).  Note
+that every pin requested will be sampled at this frequency, one after the other.
+That is, if you have code like this:
+
+.. code:: cpp
+
+    ADCInput adc(A0, A1);
+    adc.setFrequency(1000);
+
+``A0`` will be sampled at 0ms, 1ms, 2ms, etc. and ``A1`` will be sampled at 0.5ms
+1.5ms, 2.5ms, etc.  Each input is sampled at the proper frequency but offset in time
+since there is only one active ADC at a time.
+
+bool begin()/begin(long sampleRate)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Start the ADC input up with the given sample rate, or with the value set
+using the prior ``setFrequency`` call.
+
+void end()
+~~~~~~~~~~
+Stops the ADC Input device.
+
+int read()
+~~~~~~~~~~
+Reads a single sample of recorded ADC data, as a 16-bit value.  When multiple pins are
+recorded the first read will be pin 0, the second will be pin 1, etc.  Applications need
+to keep track of which pin is being returned (normally by always reading out all pins
+at once).  Will not return until data is available.
+
+int available()
+~~~~~~~~~~~~~~~
+Returns the number of samples that can be read without potentially blocking.
+
+void onReceive(void (\*fn)(void))
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Sets a callback to be called when a ADC input DMA buffer is fully filled.
+Will be in an interrupt context so the specified function must operate
+quickly and not use blocking calls like delay().
@@ -18,9 +18,10 @@ void analogReadResolution(int bits)
 Determines the resolution (in bits) of the value returned by the analogRead() function.
 Default resolution is 10bit.

-float analogReadTemp()
+float analogReadTemp(float vref = 3.3f)
 ~~~~~~~~~~~~~~~~~~~~~~
 Returns the temperature, in Celsius, of the onboard thermal sensor.
+If you have a custom Vref for the ADC on your RP2040 board, you can pass it in as a parameter.  Calling with no parameters assumes the normal, 3.3V Vref.
 This reading is not exceedingly accurate and of relatively low
 resolution, so it is not a replacement for an external temperature
 sensor in many cases.
@@ -54,9 +54,9 @@ author = u'Earle F. Philhower, III'
 # built documents.
 #
 # The short X.Y version.
-version = u'2.5.3'
+version = u'2.7.1'
 # The full version, including alpha/beta/rc tags.
-release = u'2.5.3'
+release = u'2.7.1'

 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -27,12 +27,12 @@ WiFiClientSecure documentation for more details.

    // Error checking is left as an exercise for the reader...
    HTTPClient https;
-    https.setInsecure(); // Use certs, but do not check their authenticity
+    https.setInsecure();  // Use certs, but do not check their authenticity
    if (https.begin("https://my.secure.server/url")) {
-        if (http.GET() > 0) {
-            String data = http.getString();
+        if (https.GET() > 0) {
+            String data = https.getString();
        }
-        http.end();
+        https.end();
    }

 Unlike the ESP8266 and ESP32 ``HTTPClient`` implementations it is not necessary
@@ -58,6 +58,12 @@ Sets the word clock frequency, but does not start the I2S device if not
 already running.  May be called after ``I2S::begin()`` to change the
 sample rate on-the-fly.

+bool setLSBJFormat()
+~~~~~~~~~~~~~~~~~~~~
+Enables LSB-J format for I2S output.  In this mode the MSB comes out at the
+same time as the LRCLK changes, and not the normal 1-cycle delay.  Useful for
+DAC chips like the PT8211.
+
 bool begin()/begin(long sampleRate)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Start the I2S device up with the given sample rate, or with the value set
@@ -30,6 +30,8 @@ For the latest version, always check https://github.com/earlephilhower/arduino-p
   Digital I/O <digital>
   EEPROM <eeprom>
   I2S Audio <i2s>
+   PWM Audio <pwm>
+   Microphone (and Analog Sensor) Input <adc>
   Serial USB and UARTs <serial>
   "Software Serial" PIO UART <piouart>
   Servo <servo>
@@ -39,6 +41,8 @@ For the latest version, always check https://github.com/earlephilhower/arduino-p
   USB (Arduino and Adafruit_TinyUSB) <usb>
   Multicore Processing <multicore>

+   Single File USB Drive <singlefile>
+
   FreeRTOS SMP (multicore) <freertos>

   WiFi (Pico-W Support) <wifi>
@@ -9,14 +9,6 @@ installation.

 Installing via Arduino Boards Manager
 -------------------------------------
-**Note for Windows Users**: Please do not use the Windows Store version of
-the actual Arduino application because it has issues detecting attached Pico
-boards.  Use the "Windows ZIP" or plain "Windows" executable (EXE) download
-direct from https://arduino.cc. and allow it to install any device drivers
-it suggests.  Otherwise the Pico board may not be detected.  Also, if trying
-out the 2.0 beta Arduino please install the release 1.8 version beforehand
-to ensure needed device drivers are present.
-
 1. Open up the Arduino IDE and go to File->Preferences.
 2. In the dialog that pops up, enter the following URL in the "Additional Boards Manager URLs" field:  https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json

@@ -28,6 +20,24 @@ to ensure needed device drivers are present.

   .. image:: images/install2.png

+Arduino IDE Installation Warning
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Note for Windows Users**: Please do not use the Windows Store version of
+the actual Arduino application because it has issues detecting attached Pico
+boards.  Use the "Windows ZIP" or plain "Windows" executable (EXE) download
+direct from https://arduino.cc. and allow it to install any device drivers
+it suggests.  Otherwise the Pico board may not be detected.  Also, if trying
+out the 2.0 beta Arduino please install the release 1.8 version beforehand
+to ensure needed device drivers are present.
+
+**Note for Linux Users**: If you installed the Arduino IDE using Flatpak, which 
+is common in Pop!_OS, Fedora, and Mint, among others, you may need to configure 
+Flatpak to allow the IDE access to files outside your home folder. The RP2040 
+device is sometimes mounted as a folder in /opt or /media, which Flatpak will 
+prevent the Arduino IDE from accessing. For Arduino IDE V2, override the filesystem
+restriction using ``flatpak override --user --filesystem=host cc.arduino.IDE2`` . For 
+For Arduino IDE < V2, use ``flatpak override --user --filesystem=host cc.arduino.arduinoide``.
+
 Installing via GIT
 ------------------
 To install via GIT (for latest and greatest versions):
@@ -65,25 +75,14 @@ Them hit the upload button and your sketch should upload and run.
 In some cases the Pico will encounter a hard hang and its USB port will not respond to the auto-reset request.  Should this happen, just
 follow the initial procedure of holding the BOOTSEL button down while plugging in the Pico to enter the ROM bootloader.

-Unable to Upload First Sketch
-----------------------------
-If the Arduino IDE has never seen a serial port from a working device (Pico, AVR, or any other serial port), you
-may not be able to install using the prior directions because the ``Tools->Port`` menu will be grayed out and
-empty.  In this case, a special workaround identified by @fjansson in `this issue report <https://github.com/earlephilhower/arduino-pico/issues/688>`_ .
-
-To allow subsequent uploads to automatically work, you will need to manually install a UF2 binary onto the Raspberry Pi Pico one time to
-allow it to present a Serial port for the Arduino IDE to detect and save. 
-
-Perform the following steps to program a dummy sketch:
-
-1. Open a new, empty sketch (doesn't work with a read-only example sketch).
-2. Compile it by pressing the "Verify" checkmark button.
-3. Select the ``Sketch -> Export Compiled Binary`` menu. Select a location e.g. the desktop. A folder is created there, containing a file ending in .uf2
-4. Copy this file to the Pico's drive, by drag and drop in the Explorer.
-
-The Pico restarts and now now has a serial port. Now the Port menu in Arduino is not gray anymore, select the port there.
-After this, normal uploading from the Arduino editor should work.
+Uploading the First Sketch
+--------------------------
+The first time you upload a sketch to a board, you'll need to use the built-in ROM bootloader to handle the upload and not a serial port.

+1. Hold the BOOTSEL button while plugging in the board.
+2. Select ``Tools->Port->UF2 Board`` from the menu.
+3. Upload as normal.
+4. After the board boots up, select the new serial port from the ``Tools->Port`` menu.

 Windows 7 Driver Notes
 ----------------------
@@ -136,6 +135,22 @@ For detailed usage information, please check the repo documentation available at

 * https://arduino-pico.readthedocs.io/en/latest/fs.html

+Uploading Sketches with Picotool
+--------------------------------
+Because the Picotool uses a custom device driver in the Pico to handle upload, when using the ``Upload Method->Picotool`` mode custom code needs to be run on the Pico which is not included by default for compatibility and code savings.
+
+So for the first sketch you will need to rebuild (with the ``Upload Method->Picotool`` selected in them menus) and then manually hold down BOOTSEL and insert the Pico USB cable to enter the ROM bootloader.
+
+After the initial upload, as long as the running binary was built using the ``Picotool`` upload method, then the normal upload process should work.
+
+Note that for Ubuntu and other Linux operating systems you may need to add the following lines to a new `udev` config file(``99-picotool.rules``) to allow normal users to access the special USB device the Pico exports:
+
+.. code::
+
+        echo 'SUBSYSTEM=="usb", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0003", MODE="660", GROUP="plugdev"' | sudo tee -a /etc/udev/rules.d/98-Picotool.rules
+        echo 'SUBSYSTEM=="usb", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="000a", MODE="660", GROUP="plugdev"' | sudo tee -a /etc/udev/rules.d/98-Picotool.rules
+        sudo udevadm control --reload
+
 Uploading Sketches with Picoprobe
 ---------------------------------
 If you have built a Raspberry Pi Picoprobe, you can use OpenOCD to handle your sketch uploads and for debugging with GDB.
@@ -0,0 +1,97 @@
+PWM Audio Library
+=================
+
+Relatively good quality analog audio out can be generated by using the
+RP2040 onboard PWM hardware.  It can drive an amplifier for speaker output,
+or be decoupled using a capacitor to drive a headphone-level signal.  Mono
+and stereo signals can be generated.
+
+All samples are sent to the ``PWMAudio`` library as **signed 16 bits per sample**.
+Due to frequency limitations of the PWM hardware, at higher bit rates
+these 16-bits will automatically be reduced to the maximum the hardware
+can handle.
+
+Multiple ``PWMAudio`` devices are supported, depending on availability of
+DMA channels.
+
+The interface for the ``PWMAudio`` device is very similar to the ``I2S``
+device, and most code can be ported simply by instantiating a ``PWMAudio``
+object in lieu of an ``I2S`` object.
+
+PWM Class API
+-------------
+
+PWMAudio(pin)
+~~~~~~~~~~~~~
+Creates a mono PWM output port.  Any pin can be used, but no ``analogWrite``
+calls are allowed to any other pins using that pin's PWM slice hardware.
+See the RP2040 datasheet for more details about PWM slices.
+
+PWMAudio(pin, true)
+~~~~~~~~~~~~~~~~~~~
+Creates a stereo PWM output port.  Only even pins (left signal) can be used, the next odd
+pin will automatically be assigned to the right channel (i.e. ``PWMAudio pwm(0, true);``
+will make GP0 as the left channel, GP1 as the right channel).  The same restriction as
+in mono mode applies.
+
+bool setBuffers(size_t buffers, size_t bufferWords)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Set the number of DMA buffers and their size in 32-bit words.
+Call before ``PWMAudio::begin()``.
+
+When running at high sample rates, it is recommended to increase the
+``bufferWords`` to 32 or higher (i.e. ``pwm.setBuffers(4, 32);`` ).
+
+bool setPin(pin_size_t pin)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adjusts the pin to connect to the PWM audio output.  Only legal before
+``PWMAudio::begin()``.
+
+bool setStereo(bool stereo)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adjusts the mono/stereo setting of the PWM audio output.  Only legal before
+``PWMAudio::begin()``.
+
+bool setFrequency(long sampleRate)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Sets the sample frequency, but does not start the PWM device (however if the
+device was already running, it will wontinue to run at the new frequency).
+
+bool begin()/begin(long sampleRate)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Start the PWM Audio device up with the given sample rate, or with the value set
+using the prior ``setFrequency`` call.
+
+void end()
+~~~~~~~~~~
+Stops the PWMAudio device.
+
+void flush()
+~~~~~~~~~~~~
+Waits until all the PWM Audio buffers have been output.
+
+size_t write(int16_t sample, bool sync = true)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Writes a single 16-bit sample to the buffer.  It is up to the user to keep track
+of left/right channels when in stereo mode.  In mono mode, one sample is written
+per timestep while in stereo mode two ``write()`` calls are required.
+
+This call will block (wait) until space is available to actually write
+the data if ``sync`` is not specified or set to ``true``.
+
+size_t write(const uint8_t \*buffer, size_t size)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Transfers number of bytes from an application buffer to the PWM Audio output buffer.
+Be aware that ``size`` is in *bytes** and not samples.  Size must be a multiple
+of **4 bytes**.  Will not block, so check the return value to find out how
+many bytes were actually written.
+
+int availableForWrite()
+~~~~~~~~~~~~~~~~~~~~~~~
+Returns the number of samples that can be written without potentially blocking.
+
+void onTransmit(void (\*fn)(void))
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Sets a callback to be called when a PWM Audio DMA buffer is fully transmitted.
+Will be in an interrupt context so the specified function must operate
+quickly and not use blocking calls like delay() or write to the PWM Audio.
@@ -38,12 +38,12 @@ void rp2040.reboot()
 Forces a hardware reboot of the Pico.

 Hardware Watchdog
-_________________
+-----------------

 void rp2040.wdt_begin(uint32_t delay_ms)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Enables the hardware watchdog timer with a delay value of delay_ms
-microseconds. Note that on the RP2040, once this function has called, the
+milliseconds. Note that on the RP2040, once this function has called, the
 hardware watchdog can _not_ be disabled.

 void rp2040.wdt_reset()
@@ -70,3 +70,12 @@ int rp2040.getTotalHeap()
 Returns the total heap that was available to this program at compile time (i.e.
 the Pico RAM size minus things like the ``.data`` and ``.bss`` sections and other
 overhead).
+
+Bootloader
+----------
+
+void rp2040.enableDoubleResetBootloader()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Add a call anywhere in the sketch to ``rp2040.enableDoubleResetBootloader()`` and
+the core will check for a double-tap on reset, and if found will start the USB
+bootloader.
@@ -0,0 +1,82 @@
+SingleFileDrive
+===============
+
+USB drive mode is supported through the ``SingleFileDrive`` class which
+allows the Pico to emulate a FAT-formatted USB stick while preserving the
+onboard LittleFS filesystem.  A single file can be exported this way without
+needing to use FAT as the onboard filesystem (FAT is not appropriate for
+flash-based devices without complicated wear leveling because of the update
+frequency of the FAT tables).
+
+This emulation is very simple and only allows for the reading of the single
+file, and deleting it.
+
+Callbacks, Interrupt Safety, and File Operations
+------------------------------------------------
+
+The ``SingleFileDrive`` library allows your application to get a callback
+when a PC attempts to mount or unmount the Pico as a drive.  Your app can
+also get a callback if the user attempts to delete the file (but your
+sketch does not actually need to delete the file, it's up to you).
+
+Note that when the USB drive is mounted by a PC it is not safe for your
+main sketch to make changes to the LittleFS filesystem or the file being
+exported.  So, normally, your ``onPlug`` callback will set a flag letting
+your application know not to touch the filesystem, with the ``onUnplug``
+callback clearing this flag.
+
+Also, because the USB port can be connected at any time, it is important
+to disable interrupts using ``noInterrupts()`` before writing to a file
+you will be exporting (and restoring them with ``interrupts()`` afterwards).
+It is also important to ``close()`` the file after each update, or the
+on-flash version the ``SingleFileDrive`` will attempt to export may not be
+up to date causing issues later on.
+
+See the included ``DataLoggerUSB`` sketch for an example of working with
+these limitations.
+
+Using SingleFileDrive
+---------------------
+
+Implementing the drive requires including the header file, starting LittleFS,
+defining your callbacks, and telling the library what file to export.  No
+polling or other calls are required outside of your ``setup()``.  (Note that
+the callback routines allow for a parameter to be passed to them, but in most
+cases this can be safely ignored.)
+
+.. code:: cpp
+
+        #include <LittleFS.h>
+        #include <SingleFileDrive.h>
+
+        void myPlugCB(uint32_t data) {
+            // Tell my app not to write to flash, we're connected
+        }
+
+        void myUnplugCB(uint32_t data) {
+            // I can start writing to flash again
+        }
+
+        void myDeleteDB(uint32_t data) {
+            // Maybe LittleFS.remove("myfile.txt")?  or do nothing
+        }
+
+        void setup() {
+            LittleFS.begin();
+            singleFileDrive.onPlug(myPlugCB);
+            singleFileDrive.onUnplug(myUnplugCB);
+            singleFileDrive.onDelete(myDeleteCB);
+            singleFileDrive.begin("littlefsfile.csv", "Data Recorder.csv");
+            // ... rest of setup ...
+        }
+
+        void loop() {
+            // Take some measurements, delay, etc.
+            if (okay-to-write) {
+                noInterrupts();
+                File f = LittleFS.open("littlefsfile.csv", "a");
+                f.printf("%d,%d,%d\n", data1, data2, data3);
+                f.close();
+                interrupts();
+            }
+        }
@@ -40,8 +40,6 @@ Please note that WiFi on the Pico W is a work-in-progress and there are some imp

  * Combined STA/AP mode is not supported

-  * Certain WiFi status values (RSSI, BSSID, etc.) are not available.
-
 * Multicore is supported, but only one core may run ``WiFi`` code.

  * FreeRTOS is not yet supported due to the requirement for a very different LWIP implementation.  PRs always appreciated!
@@ -72,15 +72,14 @@
 //------------- CLASS -------------//
 #define CFG_TUD_HID              (2)
 #define CFG_TUD_CDC              (1)
-#define CFG_TUD_MSC              (0)
+#define CFG_TUD_MSC              (1)
 #define CFG_TUD_MIDI             (0)
 #define CFG_TUD_VENDOR           (0)

 #define CFG_TUD_CDC_RX_BUFSIZE  (256)
 #define CFG_TUD_CDC_TX_BUFSIZE  (256)

-#define CFG_TUD_MIDI_RX_BUFSIZE (64)
-#define CFG_TUD_MIDI_TX_BUFSIZE (64)
+#define CFG_TUD_MSC_EP_BUFSIZE  (64)

 // HID buffer size Should be sufficient to hold ID (if any) + Data
 #define CFG_TUD_HID_EP_BUFSIZE  (64)
@@ -54,6 +54,11 @@ SerialPIO	KEYWORD2
 setFIFOSize	KEYWORD2
 setPollingMode	KEYWORD2

+digitalWriteFast	KEYWORD2
+digitalReadFast	KEYWORD2
+
+enableDoubleResetBootloader	KEYWORD2
+
 OUTPUT_2MA	LITERAL1
 OUTPUT_4MA	LITERAL1
 OUTPUT_8MA	LITERAL1
@@ -0,0 +1 @@
+source [find board/pico-debug.cfg]
@@ -0,0 +1,2 @@
+source [find interface/picoprobe.cfg]
+source [find target/rp2040.cfg]
@@ -9,6 +9,7 @@
 -iwithprefixbefore/pico-sdk/src/common/pico_stdlib/include
 -iwithprefixbefore/pico-sdk/src/common/pico_sync/include
 -iwithprefixbefore/pico-sdk/src/common/pico_time/include
+-iwithprefixbefore/pico-sdk/src/common/pico_usb_reset_interface/include
 -iwithprefixbefore/pico-sdk/src/common/pico_util/include
 -iwithprefixbefore/pico-sdk/src/rp2040/hardware_regs/include
 -iwithprefixbefore/pico-sdk/src/rp2040/hardware_structs/include
@@ -144,4 +144,59 @@
 -Wl,--wrap=tanhf
 -Wl,--wrap=trunc
 -Wl,--wrap=truncf
+
 -Wl,--wrap=__getreent
+
+-Wl,--wrap=malloc
+-Wl,--wrap=calloc
+-Wl,--wrap=realloc
+-Wl,--wrap=free
+
+-Wl,--wrap=pbuf_header
+-Wl,--wrap=pbuf_free
+-Wl,--wrap=pbuf_alloc
+-Wl,--wrap=pbuf_take
+-Wl,--wrap=pbuf_copy_partial
+-Wl,--wrap=pbuf_ref
+-Wl,--wrap=pbuf_get_at
+-Wl,--wrap=pbuf_get_contiguous
+-Wl,--wrap=pbuf_cat
+
+-Wl,--wrap=tcp_arg
+-Wl,--wrap=tcp_new
+-Wl,--wrap=tcp_listen
+-Wl,--wrap=tcp_listen_with_backlog
+-Wl,--wrap=tcp_accept
+-Wl,--wrap=tcp_connect
+-Wl,--wrap=tcp_write
+-Wl,--wrap=tcp_sent
+-Wl,--wrap=tcp_recv
+-Wl,--wrap=tcp_recved
+-Wl,--wrap=tcp_poll
+-Wl,--wrap=tcp_close
+-Wl,--wrap=tcp_abort
+-Wl,--wrap=tcp_err
+-Wl,--wrap=tcp_output
+-Wl,--wrap=tcp_setprio
+-Wl,--wrap=tcp_backlog_delayed
+-Wl,--wrap=tcp_backlog_accepted
+
+-Wl,--wrap=udp_new
+-Wl,--wrap=udp_remove
+-Wl,--wrap=udp_bind
+-Wl,--wrap=udp_connect
+-Wl,--wrap=udp_disconnect
+-Wl,--wrap=udp_send
+-Wl,--wrap=udp_recv
+-Wl,--wrap=udp_sendto_if
+
+-Wl,--wrap=sys_check_timeouts
+
+-Wl,--wrap=dns_gethostbyname
+-Wl,--wrap=dns_gethostbyname_addrtype
+
+-Wl,--wrap=raw_new
+-Wl,--wrap=raw_recv
+-Wl,--wrap=raw_bind
+-Wl,--wrap=raw_sendto
+-Wl,--wrap=raw_remove
@@ -0,0 +1,30 @@
+/*
+   Mono analog microphone example using electret mike on A0
+   Run using the Arduino Serial Plotter to see waveform.
+   Released to the Public Domain by Earle F. Philhower, III
+
+   Wire the mike's VCC to 3.3V on the Pico, connect the mike's
+   GND to a convenient Pico GND, and then connect mike OUT to A0
+*/
+
+#include <ADCInput.h>
+
+ADCInput mike(A0);
+// For stereo/dual mikes, could use this line instead
+//   ADCInput(A0, A1);
+
+void setup() {
+  Serial.begin(115200);
+
+  mike.begin(8000);
+
+  while (1) {
+    Serial.printf("%d\n", mike.read());
+    // For stereo/dual mikes, use this line instead
+    //   Serial.printf("%d %d\n", mike.read(), mike.read());
+  }
+}
+
+void loop() {
+  /* Nothing here */
+}
@@ -0,0 +1,25 @@
+#######################################
+# Syntax Coloring Map
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+ADCInput	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+begin	KEYWORD2
+end	KEYWORD2
+
+setPins	KEYWORD2
+setFrequency	KEYWORD2
+setBuffers	KEYWORD2
+
+onReceive	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################
@@ -0,0 +1,10 @@
+name=ADCInput
+version=1.0
+author=Earle F. Philhower, III <earlephilhower@yahoo.com>
+maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
+sentence=Records ADC values (i.e. microphone, sensors) and presents an I2S-like callback/immediate read interface
+paragraph=Records ADC values (i.e. microphone, sensors) and presents an I2S-like callback/immediate read interface
+category=Communication
+url=http://github.com/earlephilhower/arduino-pico
+architectures=rp2040
+dot_a_linkage=true
@@ -0,0 +1,172 @@
+/*
+    ADCInput
+    Records ADC values (i.e. microphone, sensors) and presents an I2S-like
+    callback/immediate read interface
+
+    Copyright (c) 2023 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <Arduino.h>
+#include "ADCInput.h"
+#include <hardware/adc.h>
+
+ADCInput::ADCInput(pin_size_t p0, pin_size_t p1, pin_size_t p2, pin_size_t p3) {
+    _running = false;
+    setPins(p0, p1, p2, p3);
+    _freq = 48000;
+    _arb = nullptr;
+    _cb = nullptr;
+    _buffers = 8;
+    _bufferWords = 0;
+}
+
+ADCInput::~ADCInput() {
+    end();
+}
+
+bool ADCInput::setBuffers(size_t buffers, size_t bufferWords) {
+    if (_running || (buffers < 3) || (bufferWords < 8)) {
+        return false;
+    }
+    _buffers = buffers;
+    _bufferWords = bufferWords;
+    return true;
+}
+
+int ADCInput::_mask(pin_size_t p) {
+    switch (p) {
+    case 26: return 1;
+    case 27: return 2;
+    case 28: return 4;
+    case 29: return 8;
+    default: return 0;
+    }
+}
+
+bool ADCInput::setPins(pin_size_t pin0, pin_size_t pin1, pin_size_t pin2, pin_size_t pin3) {
+    if (_running) {
+        return false;
+    }
+    _pinMask = _mask(pin0) | _mask(pin1) | _mask(pin2) | _mask(pin3);
+    return true;
+}
+
+bool ADCInput::setFrequency(int newFreq) {
+    _freq = newFreq * __builtin_popcount(_pinMask); // Want to sample all channels at given frequency
+    adc_set_clkdiv(48000000.0f / _freq - 1.0f);
+    return true;
+}
+
+void ADCInput::onReceive(void(*fn)(void)) {
+    _cb = fn;
+    if (_running) {
+        _arb->setCallback(_cb);
+    }
+}
+
+bool ADCInput::begin() {
+    _running = true;
+
+    _isHolding = 0;
+
+    if (!_bufferWords) {
+        _bufferWords = 16;
+    }
+
+    // Set up the GPIOs to go to ADC
+    adc_init();
+    int cnt = 0;
+    for (int mask = 1, pin = 26; pin <= 29; mask <<= 1, pin++) {
+        if (_pinMask & mask) {
+            if (!cnt) {
+                adc_select_input(pin - 26);
+            }
+            cnt++;
+            adc_gpio_init(pin);
+        }
+    }
+    adc_set_round_robin(_pinMask);
+    adc_fifo_setup(true, true, 1, false, false);
+
+    setFrequency(_freq);
+
+    _arb = new AudioBufferManager(_buffers, _bufferWords, 0, INPUT, DMA_SIZE_16);
+    _arb->begin(DREQ_ADC, (volatile void*)&adc_hw->fifo);
+    _arb->setCallback(_cb);
+
+    adc_fifo_drain();
+
+    adc_run(true);
+
+    return true;
+}
+
+void ADCInput::end() {
+    if (_running) {
+        _running = false;
+        delete _arb;
+        _arb = nullptr;
+    }
+    adc_run(false);
+    adc_fifo_drain();
+}
+
+int ADCInput::available() {
+    if (!_running) {
+        return 0;
+    } else {
+        return _arb->available();
+    }
+}
+
+int ADCInput::read() {
+    if (!_running) {
+        return -1;
+    }
+
+    if (_hasPeeked) {
+        _hasPeeked = false;
+        return _peekSaved;
+    }
+
+    if (_isHolding <= 0) {
+        _arb->read(&_holdWord, true);
+        _isHolding = 32;
+    }
+
+    int ret = _holdWord & 0x0fff;
+    _holdWord >>= 16;
+    _isHolding -= 16;
+    return ret;
+}
+
+int ADCInput::peek() {
+    if (!_running) {
+        return -1;
+    }
+    if (!_hasPeeked) {
+        _peekSaved = read();
+        _hasPeeked = true;
+    }
+    return _peekSaved;
+}
+
+void ADCInput::flush() {
+    if (_running) {
+        _arb->flush();
+    }
+}
@@ -0,0 +1,87 @@
+/*
+    ADCInput
+    Records ADC values (i.e. microphone, sensors) and presents an I2S-like
+    callback/immediate read interface
+
+    Copyright (c) 2023 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+#include <Arduino.h>
+#include "AudioBufferManager.h"
+
+class ADCInput : public Stream {
+public:
+    ADCInput(pin_size_t pin0, pin_size_t pin1 = 255, pin_size_t pin2 = 255, pin_size_t pin3 = 255);
+    virtual ~ADCInput();
+
+    bool setBuffers(size_t buffers, size_t bufferWords);
+    bool setFrequency(int newFreq);
+    bool setPins(pin_size_t pin0, pin_size_t pin1 = 255, pin_size_t pin2 = 255, pin_size_t pin3 = 255);
+
+    bool begin(long sampleRate) {
+        setFrequency(sampleRate);
+        return begin();
+    }
+
+    bool begin();
+    void end();
+
+    // from Stream
+    virtual int available() override;
+    virtual int read() override;
+    virtual int peek() override;
+    virtual void flush() override;
+
+    // from Print, not supported
+    virtual size_t write(const uint8_t *buffer, size_t size) override {
+        (void) buffer;
+        (void) size;
+        return -1;
+    }
+    virtual size_t write(uint8_t x) override {
+        (void) x;
+        return -1;
+    }
+    virtual int availableForWrite() override {
+        return 0;
+    }
+
+    // Note that these callback are called from **INTERRUPT CONTEXT** and hence
+    // should be in RAM, not FLASH, and should be quick to execute.
+    void onReceive(void(*)(void));
+
+private:
+    uint32_t _pinMask;
+
+    int _freq;
+
+    size_t _buffers;
+    size_t _bufferWords;
+
+    bool _running;
+    void (*_cb)();
+
+    bool _hasPeeked;
+    uint32_t _peekSaved;
+    uint32_t _holdWord = 0;
+    int _isHolding = 0;
+
+    int _mask(pin_size_t pin);
+
+    AudioBufferManager *_arb;
+};
@@ -110,7 +110,7 @@ void ArduinoOTAClass::begin(bool useMDNS) {
    _useMDNS = useMDNS;

    if (!_hostname.length()) {
-        char tmp[15];
+        char tmp[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 6];
        sprintf(tmp, "pico-%s", rp2040.getChipID());
        _hostname = tmp;
    }
@@ -0,0 +1,10 @@
+name=AudioBufferManager
+version=1.0.0
+author=Earle F. Philhower, III <earlephilhower@yahoo.com>
+maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
+sentence=Manages DMA buffers for audio output
+paragraph=Manages DMA buffers for audio output
+category=Device Control
+url=https://github.com/earlephilhower/arduino-pico
+architectures=rp2040
+dot_a_linkage=true
@@ -0,0 +1,281 @@
+/*
+    AudioBufferManager for Raspnerry Pi Pico RP2040
+    Implements a DMA controlled linked-list series of buffers
+
+    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <Arduino.h>
+#include "hardware/dma.h"
+#include "hardware/irq.h"
+#include "AudioBufferManager.h"
+
+static int                 __channelCount = 0;    // # of channels left.  When we hit 0, then remove our handler
+static AudioBufferManager* __channelMap[12];      // Lets the IRQ handler figure out where to dispatch to
+
+AudioBufferManager::AudioBufferManager(size_t bufferCount, size_t bufferWords, int32_t silenceSample, PinMode direction, enum dma_channel_transfer_size dmaSize) {
+    _running = false;
+
+    // Need at least 2 DMA buffers and 1 user or this isn't going to work at all
+    if (bufferCount < 3) {
+        bufferCount = 3;
+    }
+
+    _bufferCount = bufferCount;
+    _wordsPerBuffer = bufferWords;
+    _isOutput = direction == OUTPUT;
+    _dmaSize = dmaSize;
+    _overunderflow = false;
+    _callback = nullptr;
+    _userOff = 0;
+
+    // Create the silence buffer, fill with appropriate value
+    _silence = new AudioBuffer;
+    _silence->next = nullptr;
+    _silence->buff = new uint32_t[_wordsPerBuffer];
+    for (uint32_t x = 0; x < _wordsPerBuffer; x++) {
+        _silence->buff[x] = silenceSample;
+    }
+
+    // No filled buffers yet
+    _filled = nullptr;
+
+    // Create all buffers on the empty chain
+    _empty = nullptr;
+    for (size_t i = 0; i < bufferCount; i++) {
+        auto ab = new AudioBuffer;
+        ab->buff = new uint32_t[_wordsPerBuffer];
+        bzero(ab->buff, _wordsPerBuffer * 4);
+        ab->next = nullptr;
+        _addToList(&_empty, ab);
+    }
+
+    _active[0] = _silence;
+    _active[1] = _silence;
+}
+
+AudioBufferManager::~AudioBufferManager() {
+    if (_running) {
+        _running = false;
+        for (auto i = 0; i < 2; i++) {
+            dma_channel_set_irq0_enabled(_channelDMA[i], false);
+            __channelMap[_channelDMA[i]] = nullptr;
+            dma_channel_abort(_channelDMA[i]);
+            dma_channel_unclaim(_channelDMA[i]);
+        }
+        __channelCount--;
+        if (!__channelCount) {
+            irq_set_enabled(DMA_IRQ_0, false);
+            // TODO - how can we know if there are no other parts of the core using DMA0 IRQ??
+            irq_remove_handler(DMA_IRQ_0, _irq);
+        }
+    }
+    for (int i = 0; i < 2; i++) {
+        if (_active[i] != _silence) {
+            _deleteAudioBuffer(_active[i]);
+        }
+    }
+    while (_filled) {
+        auto x = _filled->next;
+        _deleteAudioBuffer(_filled);
+        _filled = x;
+    }
+    while (_empty) {
+        auto x = _empty->next;
+        _deleteAudioBuffer(_empty);
+        _empty = x;
+    }
+    _deleteAudioBuffer(_silence);
+}
+
+void AudioBufferManager::setCallback(void (*fn)()) {
+    _callback = fn;
+}
+
+bool AudioBufferManager::begin(int dreq, volatile void *pioFIFOAddr) {
+    _running = true;
+
+    // Get ping and pong DMA channels
+    for (auto i = 0; i < 2; i++) {
+        _channelDMA[i] = dma_claim_unused_channel(true);
+        if (_channelDMA[i] == -1) {
+            if (i == 1) {
+                dma_channel_unclaim(_channelDMA[0]);
+            }
+            return false;
+        }
+    }
+    bool needSetIRQ = __channelCount == 0;
+    // Need to know both channels to set up ping-pong, so do in 2 stages
+    for (auto i = 0; i < 2; i++) {
+        dma_channel_config c = dma_channel_get_default_config(_channelDMA[i]);
+        channel_config_set_transfer_data_size(&c, _dmaSize); // 16b/32b transfers into PIO FIFO
+        if (_isOutput) {
+            channel_config_set_read_increment(&c, true); // Reading incrementing addresses
+            channel_config_set_write_increment(&c, false); // Writing to the same FIFO address
+        } else {
+            channel_config_set_read_increment(&c, false); // Reading same FIFO address
+            channel_config_set_write_increment(&c, true); // Writing to incrememting buffers
+        }
+        channel_config_set_dreq(&c, dreq); // Wait for the PIO TX FIFO specified
+        channel_config_set_chain_to(&c, _channelDMA[i ^ 1]); // Start other channel when done
+        channel_config_set_irq_quiet(&c, false); // Need IRQs
+
+        if (_isOutput) {
+            dma_channel_configure(_channelDMA[i], &c, pioFIFOAddr, _silence->buff, _wordsPerBuffer * (_dmaSize == DMA_SIZE_16 ? 2 : 1), false);
+        } else {
+            _active[i] = _takeFromList(&_empty);
+            dma_channel_configure(_channelDMA[i], &c, _active[i]->buff, pioFIFOAddr, _wordsPerBuffer * (_dmaSize == DMA_SIZE_16 ? 2 : 1), false);
+        }
+        dma_channel_set_irq0_enabled(_channelDMA[i], true);
+        __channelMap[_channelDMA[i]] = this;
+        __channelCount++;
+    }
+    if (needSetIRQ) {
+        irq_add_shared_handler(DMA_IRQ_0, _irq, PICO_SHARED_IRQ_HANDLER_DEFAULT_ORDER_PRIORITY);
+        irq_set_enabled(DMA_IRQ_0, true);
+    }
+
+    dma_channel_start(_channelDMA[0]);
+    return true;
+}
+
+// Following 2 routines use volatile because the IRQ may update the "this"
+// pointer and change the list head while we are waiting.  Volatile will
+// cause GCC to keep re-reading from memory and not use cached value read
+// on the first pass.
+
+bool AudioBufferManager::write(uint32_t v, bool sync) {
+    if (!_running || !_isOutput) {
+        return false;
+    }
+    AudioBuffer ** volatile p = (AudioBuffer ** volatile)&_empty;
+    if (!*p) {
+        if (!sync) {
+            return false;
+        } else {
+            while (!*p) {
+                /* noop busy wait */
+            }
+        }
+    }
+    (*p)->buff[_userOff++] = v;
+    if (_userOff == _wordsPerBuffer) {
+        _addToList(&_filled, _takeFromList(p));
+        _userOff = 0;
+    }
+    return true;
+}
+
+bool AudioBufferManager::read(uint32_t *v, bool sync) {
+    if (!_running || _isOutput) {
+        return false;
+    }
+
+    AudioBuffer ** volatile p = (AudioBuffer ** volatile)&_filled;
+    if (!*p) {
+        if (!sync) {
+            return false;
+        } else {
+            while (!*p) {
+                /* noop busy wait */
+            }
+        }
+    }
+    auto ret = (*p)->buff[_userOff++];
+    if (_userOff == _wordsPerBuffer) {
+        _addToList(&_empty, _takeFromList(p));
+        _userOff = 0;
+    }
+    *v = ret;
+    return true;
+}
+
+bool AudioBufferManager::getOverUnderflow() {
+    bool hold = _overunderflow;
+    _overunderflow = false;
+    return hold;
+}
+
+int AudioBufferManager::available() {
+    AudioBuffer *p = _isOutput ? _empty : _filled;
+
+    if (!_running || !p) {
+        // No buffers available...
+        return 0;
+    }
+
+    int avail = _wordsPerBuffer - _userOff; // Currently available in this buffer
+
+    // Each add'l buffer has wpb spaces...
+    auto x = p->next;
+    while (x) {
+        avail += _wordsPerBuffer;
+        x = x->next;
+    }
+    return avail;
+}
+
+void AudioBufferManager::flush() {
+    AudioBuffer ** volatile a = (AudioBuffer ** volatile)&_active[0];
+    AudioBuffer ** volatile b = (AudioBuffer ** volatile)&_active[1];
+    AudioBuffer ** volatile c = (AudioBuffer ** volatile)&_filled;
+    while (*c && (*b != (AudioBuffer * volatile)_silence) && (*a != (AudioBuffer * volatile)_silence)) {
+        // busy wait until all user written data enroute
+    }
+}
+
+void __not_in_flash_func(AudioBufferManager::_dmaIRQ)(int channel) {
+    if (!_running) {
+        return;
+    }
+    if (_isOutput) {
+        if (_active[0] != _silence) {
+            _addToList(&_empty, _active[0]);
+        }
+        _active[0] = _active[1];
+        if (!_filled) {
+            _active[1] = _silence;
+        } else {
+            _active[1] = _takeFromList(&_filled);
+        }
+        _overunderflow = _overunderflow | (_active[1] == _silence);
+        dma_channel_set_read_addr(channel, _active[0]->buff, false);
+    } else {
+        if (_empty) {
+            _addToList(&_filled, _active[0]);
+            _active[0] = _active[1];
+            _active[1] = _takeFromList(&_empty);
+        } else {
+            _overunderflow = true;
+        }
+        dma_channel_set_write_addr(channel, _active[0]->buff, false);
+    }
+    dma_channel_set_trans_count(channel, _wordsPerBuffer * (_dmaSize == DMA_SIZE_16 ? 2 : 1), false);
+    dma_channel_acknowledge_irq0(channel);
+    if (_callback) {
+        _callback();
+    }
+}
+
+void __not_in_flash_func(AudioBufferManager::_irq)() {
+    for (size_t i = 0; i < sizeof(__channelMap); i++) {
+        if (dma_channel_get_irq0_status(i) && __channelMap[i]) {
+            __channelMap[i]->_dmaIRQ(i);
+        }
+    }
+}
@@ -0,0 +1,102 @@
+/*
+    AudioBufferManager for Rasperry Pi Pico
+    Implements a DMA controlled linked-list series of buffers
+
+    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+#include <Arduino.h>
+#include "hardware/dma.h"
+
+class AudioBufferManager {
+public:
+    AudioBufferManager(size_t bufferCount, size_t bufferWords, int32_t silenceSample, PinMode direction = OUTPUT, enum dma_channel_transfer_size dmaSize = DMA_SIZE_32);
+    ~AudioBufferManager();
+
+    void setCallback(void (*fn)());
+
+    bool begin(int dreq, volatile void *pioFIFOAddr);
+
+    bool write(uint32_t v, bool sync = true);
+    bool read(uint32_t *v, bool sync = true);
+    void flush();
+
+    bool getOverUnderflow();
+    int available();
+
+private:
+    void _dmaIRQ(int channel);
+    static void _irq();
+
+    typedef struct AudioBuffer {
+        struct AudioBuffer *next;
+        uint32_t *buff;
+    } AudioBuffer;
+
+    bool _running = false;
+
+    AudioBuffer *_silence = nullptr; // A single silence buffer to be looped on underflow
+    AudioBuffer *_filled = nullptr;  // List of buffers ready to be played
+    AudioBuffer *_empty = nullptr;   // List of buffers waiting to be filled. *_empty = currently writing
+    AudioBuffer *_active[2] = { nullptr, nullptr }; // The 2 buffers currently in use for DMA
+
+    // Can't use std::list because we need to put in RAM for IRQ use, so roll our own
+    void __not_in_flash_func(_addToList)(AudioBuffer **list, AudioBuffer *element) {
+        noInterrupts();
+        // Find end of list, if any
+        while ((*list) && ((*list)->next != nullptr)) {
+            list = &(*list)->next;
+        }
+        if (*list) {
+            (*list)->next = element;
+        } else {
+            *list = element;
+        }
+        element->next = nullptr; // Belt and braces
+        interrupts();
+    }
+
+    AudioBuffer *__not_in_flash_func(_takeFromList)(AudioBuffer **list) {
+        noInterrupts();
+        auto ret = *list;
+        if (ret) {
+            *list = ret->next;
+        }
+        interrupts();
+        return ret;
+    }
+
+    void _deleteAudioBuffer(AudioBuffer *ab) {
+        delete[] ab->buff;
+        delete ab;
+    }
+
+    int _bitsPerSample;
+    size_t _wordsPerBuffer;
+    size_t _bufferCount;
+    enum dma_channel_transfer_size _dmaSize;
+    bool _isOutput;
+
+    int _channelDMA[2];
+    void (*_callback)();
+
+    bool _overunderflow;
+
+    // User buffer pointer
+    size_t _userOff = 0;
+};
@@ -45,7 +45,7 @@ void EEPROMClass::begin(size_t size) {
        size = 4096;
    }

-    _size = (size + 255) & (~255);  // Flash writes limited to 256 byte boundaries
+    size = (size + 255) & (~255);  // Flash writes limited to 256 byte boundaries

    // In case begin() is called a 2nd+ time, don't reallocate if size is the same
    if (_data && size != _size) {
@@ -55,6 +55,8 @@ void EEPROMClass::begin(size_t size) {
        _data = new uint8_t[size];
    }

+    _size = size;
+
    memcpy(_data, _sector, _size);

    _dirty = false; //make sure dirty is cleared in case begin() is called 2nd+ time
@@ -30,7 +30,7 @@ void ps() {
  Serial.printf("# Tasks: %d\n", tasks);
  Serial.println("ID, NAME, STATE, PRIO, CYCLES");
  for (int i=0; i < tasks; i++) {
-    Serial.printf("%d: %-16s %-10s %d %lu\n", i, pxTaskStatusArray[i].pcTaskName, eTaskStateName[pxTaskStatusArray[i].eCurrentState], pxTaskStatusArray[i].uxCurrentPriority, pxTaskStatusArray[i].ulRunTimeCounter);
+    Serial.printf("%d: %-16s %-10s %d %lu\n", i, pxTaskStatusArray[i].pcTaskName, eTaskStateName[pxTaskStatusArray[i].eCurrentState], (int)pxTaskStatusArray[i].uxCurrentPriority, pxTaskStatusArray[i].ulRunTimeCounter);
  }
  delete[] pxTaskStatusArray;
 }
@@ -59,7 +59,7 @@ volatile bool __usbInitted = false;

 static void __core0(void *params) {
    (void) params;
-#ifndef NO_USB
+#if !defined(NO_USB) && !defined(USE_TINYUSB)
    while (!__usbInitted) {
        delay(1);
    }
@@ -81,7 +81,7 @@ static void __core0(void *params) {

 static void __core1(void *params) {
    (void) params;
-#ifndef NO_USB
+#if !defined(NO_USB) && !defined(USE_TINYUSB)
    while (!__usbInitted) {
        delay(1);
    }
@@ -414,6 +414,10 @@ extern "C" {
        xSemaphoreTake(mtx, portMAX_DELAY);
    }

+    void __freertos_mutex_take_from_isr(SemaphoreHandle_t mtx) {
+        xSemaphoreTakeFromISR(mtx, NULL);
+    }
+
    int __freertos_mutex_try_take(SemaphoreHandle_t mtx) {
        return xSemaphoreTake(mtx, 0);
    }
@@ -422,6 +426,10 @@ extern "C" {
        xSemaphoreGive(mtx);
    }

+    void __freertos_mutex_give_from_isr(SemaphoreHandle_t mtx) {
+        xSemaphoreGiveFromISR(mtx, NULL);
+    }
+
    void __freertos_recursive_mutex_take(SemaphoreHandle_t mtx) {
        xSemaphoreTakeRecursive(mtx, portMAX_DELAY);
    }
@@ -18,6 +18,8 @@ setBCLK	KEYWORD2
 setDATA	KEYWORD2
 setBitsPerSample	KEYWORD2
 setFrequency	KEYWORD2
+setBuffers	KEYWORD2
+setLSBJFormat	KEYWORD2

 read8	KEYWORD2
 read16	KEYWORD2
@@ -1,256 +0,0 @@
-/*
-    AudioRingBuffer for Raspnerry Pi Pico RP2040
-    Implements a ring buffer for PIO DMA for I2S read or write
-
-    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-*/
-
-#include <Arduino.h>
-#include <vector>
-#include "hardware/dma.h"
-#include "hardware/irq.h"
-#include "hardware/pio.h"
-#include "pio_i2s.pio.h"
-#include "AudioRingBuffer.h"
-
-static int              __channelCount = 0;    // # of channels left.  When we hit 0, then remove our handler
-static AudioRingBuffer* __channelMap[12];      // Lets the IRQ handler figure out where to dispatch to
-
-AudioRingBuffer::AudioRingBuffer(size_t bufferCount, size_t bufferWords, int32_t silenceSample, PinMode direction) {
-    _running = false;
-    _silenceSample = silenceSample;
-    _bufferCount = bufferCount;
-    _wordsPerBuffer = bufferWords;
-    _isOutput = direction == OUTPUT;
-    _overunderflow = false;
-    _callback = nullptr;
-    _userBuffer = -1;
-    _userOff = 0;
-    for (size_t i = 0; i < bufferCount; i++) {
-        auto ab = new AudioBuffer;
-        ab->buff = new uint32_t[_wordsPerBuffer];
-        ab->empty = true;
-        _buffers.push_back(ab);
-    }
-}
-
-AudioRingBuffer::~AudioRingBuffer() {
-    if (_running) {
-        for (auto i = 0; i < 2; i++) {
-            dma_channel_set_irq0_enabled(_channelDMA[i], false);
-            dma_channel_unclaim(_channelDMA[i]);
-            __channelMap[_channelDMA[i]] = nullptr;
-        }
-        while (_buffers.size()) {
-            auto ab = _buffers.back();
-            _buffers.pop_back();
-            delete[] ab->buff;
-            delete ab;
-        }
-        __channelCount--;
-        if (!__channelCount) {
-            irq_set_enabled(DMA_IRQ_0, false);
-            // TODO - how can we know if there are no other parts of the core using DMA0 IRQ??
-            irq_remove_handler(DMA_IRQ_0, _irq);
-        }
-    }
-}
-
-void AudioRingBuffer::setCallback(void (*fn)()) {
-    _callback = fn;
-}
-
-bool AudioRingBuffer::begin(int dreq, volatile void *pioFIFOAddr) {
-    _running = true;
-    // Set all buffers to silence, empty
-    for (auto buff : _buffers) {
-        buff->empty = true;
-        if (_isOutput) {
-            for (uint32_t x = 0; x < _wordsPerBuffer; x++) {
-                buff->buff[x] = _silenceSample;
-            }
-        }
-    }
-    // Get ping and pong DMA channels
-    for (auto i = 0; i < 2; i++) {
-        _channelDMA[i] = dma_claim_unused_channel(true);
-        if (_channelDMA[i] == -1) {
-            if (i == 1) {
-                dma_channel_unclaim(_channelDMA[0]);
-            }
-            return false;
-        }
-    }
-    bool needSetIRQ = __channelCount == 0;
-    // Need to know both channels to set up ping-pong, so do in 2 stages
-    for (auto i = 0; i < 2; i++) {
-        dma_channel_config c = dma_channel_get_default_config(_channelDMA[i]);
-        channel_config_set_transfer_data_size(&c, DMA_SIZE_32); // 32b transfers into PIO FIFO
-        if (_isOutput) {
-            channel_config_set_read_increment(&c, true); // Reading incrementing addresses
-            channel_config_set_write_increment(&c, false); // Writing to the same FIFO address
-        } else {
-            channel_config_set_read_increment(&c, false); // Reading same FIFO address
-            channel_config_set_write_increment(&c, true); // Writing to incrememting buffers
-        }
-        channel_config_set_dreq(&c, dreq); // Wait for the PIO TX FIFO specified
-        channel_config_set_chain_to(&c, _channelDMA[i ^ 1]); // Start other channel when done
-        channel_config_set_irq_quiet(&c, false); // Need IRQs
-
-        if (_isOutput) {
-            dma_channel_configure(_channelDMA[i], &c, pioFIFOAddr, _buffers[i]->buff, _wordsPerBuffer, false);
-        } else {
-            dma_channel_configure(_channelDMA[i], &c, _buffers[i]->buff, pioFIFOAddr, _wordsPerBuffer, false);
-        }
-        dma_channel_set_irq0_enabled(_channelDMA[i], true);
-        __channelMap[_channelDMA[i]] = this;
-        __channelCount++;
-    }
-    if (needSetIRQ) {
-        irq_add_shared_handler(DMA_IRQ_0, _irq, PICO_SHARED_IRQ_HANDLER_DEFAULT_ORDER_PRIORITY);
-        irq_set_enabled(DMA_IRQ_0, true);
-    }
-    _curBuffer = 0;
-    _nextBuffer = 2 % _bufferCount;
-    dma_channel_start(_channelDMA[0]);
-    return true;
-}
-
-bool AudioRingBuffer::write(uint32_t v, bool sync) {
-    if (!_running || !_isOutput) {
-        return false;
-    }
-    if (_userBuffer == -1) {
-        // First write or overflow, pick spot 2 buffers out
-        _userBuffer = (_nextBuffer + 2) % _bufferCount;
-        _userOff = 0;
-    }
-    if (!_buffers[_userBuffer]->empty) {
-        if (!sync) {
-            return false;
-        } else {
-            while (!_buffers[_userBuffer]->empty) {
-                /* noop busy wait */
-            }
-        }
-    }
-    if (_userBuffer == _curBuffer) {
-        if (!sync) {
-            return false;
-        } else {
-            while (_userBuffer == _curBuffer) {
-                /* noop busy wait */
-            }
-        }
-    }
-    _buffers[_userBuffer]->buff[_userOff++] = v;
-    if (_userOff == _wordsPerBuffer) {
-        _buffers[_userBuffer]->empty = false;
-        _userBuffer = (_userBuffer + 1) % _bufferCount;
-        _userOff = 0;
-    }
-    return true;
-}
-
-bool AudioRingBuffer::read(uint32_t *v, bool sync) {
-    if (!_running || _isOutput) {
-        return false;
-    }
-    if (_userBuffer == -1) {
-        // First write or overflow, pick last filled buffer
-        _userBuffer = (_curBuffer - 1 + _bufferCount) % _bufferCount;
-        _userOff = 0;
-    }
-    if (_buffers[_userBuffer]->empty) {
-        if (!sync) {
-            return false;
-        } else {
-            while (_buffers[_userBuffer]->empty) {
-                /* noop busy wait */
-            }
-        }
-    }
-    if (_userBuffer == _curBuffer) {
-        if (!sync) {
-            return false;
-        } else {
-            while (_userBuffer == _curBuffer) {
-                /* noop busy wait */
-            }
-        }
-    }
-    auto ret = _buffers[_userBuffer]->buff[_userOff++];
-    if (_userOff == _wordsPerBuffer) {
-        _buffers[_userBuffer]->empty = true;
-        _userBuffer = (_userBuffer + 1) % _bufferCount;
-        _userOff = 0;
-    }
-    *v = ret;
-    return true;
-}
-
-bool AudioRingBuffer::getOverUnderflow() {
-    bool hold = _overunderflow;
-    _overunderflow = false;
-    return hold;
-}
-
-int AudioRingBuffer::available() {
-    if (!_running) {
-        return 0;
-    }
-    int avail;
-    avail = _wordsPerBuffer - _userOff;
-    avail += ((_bufferCount + _curBuffer - _userBuffer) % _bufferCount) * _wordsPerBuffer;
-    return avail;
-}
-
-void AudioRingBuffer::flush() {
-    while (_curBuffer != _userBuffer) {
-        // busy wait
-    }
-}
-
-void __not_in_flash_func(AudioRingBuffer::_dmaIRQ)(int channel) {
-    if (_isOutput) {
-        for (uint32_t x = 0; x < _wordsPerBuffer; x++) {
-            _buffers[_curBuffer]->buff[x] = _silenceSample;
-        }
-        _buffers[_curBuffer]-> empty = true;
-        _overunderflow = _overunderflow | _buffers[_nextBuffer]->empty;
-        dma_channel_set_read_addr(channel, _buffers[_nextBuffer]->buff, false);
-    } else {
-        _buffers[_curBuffer]-> empty = false;
-        _overunderflow = _overunderflow | !_buffers[_nextBuffer]->empty;
-        dma_channel_set_write_addr(channel, _buffers[_nextBuffer]->buff, false);
-    }
-    dma_channel_set_trans_count(channel, _wordsPerBuffer, false);
-    _curBuffer = (_curBuffer + 1) % _bufferCount;
-    _nextBuffer = (_nextBuffer + 1) % _bufferCount;
-    dma_channel_acknowledge_irq0(channel);
-    if (_callback) {
-        _callback();
-    }
-}
-
-void __not_in_flash_func(AudioRingBuffer::_irq)() {
-    for (size_t i = 0; i < sizeof(__channelMap); i++) {
-        if (dma_channel_get_irq0_status(i) && __channelMap[i]) {
-            __channelMap[i]->_dmaIRQ(i);
-        }
-    }
-}
@@ -1,69 +0,0 @@
-/*
-    AudioRingBuffer for Rasperry Pi Pico
-    Implements a ring buffer for PIO DMA for I2S read or write
-
-    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-*/
-
-#pragma once
-#include <Arduino.h>
-#include <vector>
-
-class AudioRingBuffer {
-public:
-    AudioRingBuffer(size_t bufferCount, size_t bufferWords, int32_t silenceSample, PinMode direction = OUTPUT);
-    ~AudioRingBuffer();
-
-    void setCallback(void (*fn)());
-
-    bool begin(int dreq, volatile void *pioFIFOAddr);
-
-    bool write(uint32_t v, bool sync = true);
-    bool read(uint32_t *v, bool sync = true);
-    void flush();
-
-    bool getOverUnderflow();
-    int available();
-
-private:
-    void _dmaIRQ(int channel);
-    static void _irq();
-
-    typedef struct {
-        uint32_t *buff;
-        volatile bool empty;
-    } AudioBuffer;
-
-    bool _running = false;
-    std::vector<AudioBuffer*> _buffers;
-    volatile int _curBuffer;
-    volatile int _nextBuffer;
-    size_t _chunkSampleCount;
-    int _bitsPerSample;
-    size_t _wordsPerBuffer;
-    size_t _bufferCount;
-    bool _isOutput;
-    int32_t _silenceSample;
-    int _channelDMA[2];
-    void (*_callback)();
-
-    bool _overunderflow;
-
-    // User buffer pointer
-    int _userBuffer = -1;
-    size_t _userOff = 0;
-};
@@ -27,15 +27,31 @@ I2S::I2S(PinMode direction) {
    _running = false;
    _bps = 16;
    _writtenHalf = false;
+    _isOutput = direction == OUTPUT;
    _pinBCLK = 26;
    _pinDOUT = 28;
+#ifdef PIN_I2S_BCLK
+    _pinBCLK = PIN_I2S_BCLK;
+#endif
+
+#ifdef PIN_I2S_DOUT
+    if (_isOutput) {
+        _pinDOUT = PIN_I2S_DOUT;
+    }
+#endif
+
+#ifdef PIN_I2S_DIN
+    if (!_isOutput) {
+        _pinDOUT = PIN_I2S_DIN;
+    }
+#endif
    _freq = 48000;
    _arb = nullptr;
-    _isOutput = direction == OUTPUT;
    _cb = nullptr;
    _buffers = 8;
-    _bufferWords = 16;
+    _bufferWords = 0;
    _silenceSample = 0;
+    _isLSBJ = false;
 }

 I2S::~I2S() {
@@ -84,6 +100,14 @@ bool I2S::setFrequency(int newFreq) {
    return true;
 }

+bool I2S::setLSBJFormat() {
+    if (_running || !_isOutput) {
+        return false;
+    }
+    _isLSBJ = true;
+    return true;
+}
+
 void I2S::onTransmit(void(*fn)(void)) {
    if (_isOutput) {
        _cb = fn;
@@ -106,10 +130,14 @@ bool I2S::begin() {
    _running = true;
    _hasPeeked = false;
    int off = 0;
-    _i2s = new PIOProgram(_isOutput ? &pio_i2s_out_program : &pio_i2s_in_program);
+    _i2s = new PIOProgram(_isOutput ? (_isLSBJ ? &pio_lsbj_out_program : &pio_i2s_out_program) : &pio_i2s_in_program);
    _i2s->prepare(&_pio, &_sm, &off);
    if (_isOutput) {
-        pio_i2s_out_program_init(_pio, _sm, off, _pinDOUT, _pinBCLK, _bps);
+        if (_isLSBJ) {
+            pio_lsbj_out_program_init(_pio, _sm, off, _pinDOUT, _pinBCLK, _bps);
+        } else {
+            pio_i2s_out_program_init(_pio, _sm, off, _pinDOUT, _pinBCLK, _bps);
+        }
    } else {
        pio_i2s_in_program_init(_pio, _sm, off, _pinDOUT, _pinBCLK, _bps);
    }
@@ -121,7 +149,10 @@ bool I2S::begin() {
        uint16_t a = _silenceSample & 0xffff;
        _silenceSample = (a << 16) | a;
    }
-    _arb = new AudioRingBuffer(_buffers, _bufferWords, _silenceSample, _isOutput ? OUTPUT : INPUT);
+    if (!_bufferWords) {
+        _bufferWords = 16 * (_bps == 32 ? 2 : 1);
+    }
+    _arb = new AudioBufferManager(_buffers, _bufferWords, _silenceSample, _isOutput ? OUTPUT : INPUT);
    _arb->begin(pio_get_dreq(_pio, _sm, _isOutput), _isOutput ? &_pio->txf[_sm] : (volatile void*)&_pio->rxf[_sm]);
    _arb->setCallback(_cb);
    pio_sm_set_enabled(_pio, _sm, true);
@@ -130,18 +161,24 @@ bool I2S::begin() {
 }

 void I2S::end() {
-    _running = false;
-    delete _arb;
-    _arb = nullptr;
-    delete _i2s;
-    _i2s = nullptr;
+    if (_running) {
+        pio_sm_set_enabled(_pio, _sm, false);
+        _running = false;
+        delete _arb;
+        _arb = nullptr;
+        delete _i2s;
+        _i2s = nullptr;
+    }
 }

 int I2S::available() {
-    if (!_running || _isOutput) {
+    if (!_running) {
        return 0;
+    } else if (_isOutput) {
+        return availableForWrite(); // Do what I mean, not what I say
+    } else {
+        return _arb->available();
    }
-    return _arb->available();
 }

 int I2S::read() {
@@ -154,9 +191,9 @@ int I2S::read() {
        return _peekSaved;
    }

-    if (_wasHolding <= 0) {
+    if (_isHolding <= 0) {
        read(&_holdWord, true);
-        _wasHolding = 32;
+        _isHolding = 32;
    }

    int ret;
@@ -164,18 +201,18 @@ int I2S::read() {
    case 8:
        ret = _holdWord >> 24;
        _holdWord <<= 8;
-        _wasHolding -= 8;
+        _isHolding -= 8;
        return ret;
    case 16:
        ret = _holdWord >> 16;
        _holdWord <<=  16;
-        _wasHolding -= 32;
+        _isHolding -= 32;
        return ret;
    case 24:
    case 32:
    default:
        ret = _holdWord;
-        _wasHolding = 0;
+        _isHolding = 0;
        return ret;
    }
 }
@@ -204,26 +241,26 @@ size_t I2S::_writeNatural(int32_t s) {
    switch (_bps) {
    case 8:
        _holdWord |= s & 0xff;
-        if (_wasHolding >= 24) {
+        if (_isHolding >= 24) {
            auto ret = write(_holdWord, true);
            _holdWord = 0;
-            _wasHolding = 0;
+            _isHolding = 0;
            return ret;
        } else {
            _holdWord <<= 8;
-            _wasHolding += 8;
+            _isHolding += 8;
            return 1;
        }
    case 16:
        _holdWord |= s & 0xffff;
-        if (_wasHolding) {
+        if (_isHolding) {
            auto ret = write(_holdWord, true);
            _holdWord = 0;
-            _wasHolding = 0;
+            _isHolding = 0;
            return ret;
        } else {
            _holdWord <<= 16;
-            _wasHolding = 16;
+            _isHolding = 16;
            return 1;
        }
    case 24:
@@ -280,13 +317,13 @@ bool I2S::read8(int8_t *l, int8_t *r) {
    if (!_running || _isOutput) {
        return false;
    }
-    if (_wasHolding) {
+    if (_isHolding) {
        *l = (_holdWord >> 8) & 0xff;
        *r = (_holdWord >> 0) & 0xff;
-        _wasHolding = 0;
+        _isHolding = 0;
    } else {
        read(&_holdWord, true);
-        _wasHolding = 16;
+        _isHolding = 16;
        *l = (_holdWord >> 24) & 0xff;
        *r = (_holdWord >> 16) & 0xff;
    }
@@ -21,8 +21,7 @@

 #pragma once
 #include <Arduino.h>
-#include <vector>
-#include "AudioRingBuffer.h"
+#include "AudioBufferManager.h"

 class I2S : public Stream {
 public:
@@ -34,6 +33,7 @@ public:
    bool setBitsPerSample(int bps);
    bool setBuffers(size_t buffers, size_t bufferWords, int32_t silenceSample = 0);
    bool setFrequency(int newFreq);
+    bool setLSBJFormat();

    bool begin(long sampleRate) {
        setFrequency(sampleRate);
@@ -105,6 +105,7 @@ private:
    size_t _buffers;
    size_t _bufferWords;
    int32_t _silenceSample;
+    bool _isLSBJ;
    bool _isOutput;

    bool _running;
@@ -117,11 +118,11 @@ private:
    bool _writtenHalf;

    int32_t _holdWord = 0;
-    int _wasHolding = 0;
+    int _isHolding = 0;

    void (*_cb)();

-    AudioRingBuffer *_arb;
+    AudioBufferManager *_arb;
    PIOProgram *_i2s;
    PIO _pio;
    int _sm;
@@ -41,6 +41,29 @@ right:
    out pins, 1      side 0b00 ; Last bit of right also has WCLK change
    ; Loop back to beginning...

+
+.program pio_lsbj_out
+.side_set 2   ; 0 = bclk, 1=wclk
+
+; The C code should place (number of bits/sample - 2) in Y and
+; also update the SHIFTCTRL to be 24 or 32 as appropriate
+
+;                           +----- WCLK
+;                           |+---- BCLK
+    mov x, y         side 0b01
+left:
+    out pins, 1      side 0b10
+    jmp x--, left    side 0b11
+    out pins, 1      side 0b10
+
+    mov x, y         side 0b11
+right:
+    out pins, 1      side 0b00
+    jmp x--, right   side 0b01
+    out pins, 1      side 0b00
+    ; Loop back to beginning...
+
+
    
 .program pio_i2s_in ; Note this is the same as _out, just "in" and not "out"
 .side_set 2   ; 0 = bclk, 1=wclk
@@ -73,7 +96,28 @@ static inline void pio_i2s_out_program_init(PIO pio, uint sm, uint offset, uint
    pio_gpio_init(pio, clock_pin_base + 1);

    pio_sm_config sm_config = pio_i2s_out_program_get_default_config(offset);
-    
+
+    sm_config_set_out_pins(&sm_config, data_pin, 1);
+    sm_config_set_sideset_pins(&sm_config, clock_pin_base);
+    sm_config_set_out_shift(&sm_config, false, true, (bits <= 16) ? 2 * bits : bits);
+    sm_config_set_fifo_join(&sm_config, PIO_FIFO_JOIN_TX);
+
+    pio_sm_init(pio, sm, offset, &sm_config);
+
+    uint pin_mask = (1u << data_pin) | (3u << clock_pin_base);
+    pio_sm_set_pindirs_with_mask(pio, sm, pin_mask, pin_mask);
+    pio_sm_set_pins(pio, sm, 0); // clear pins
+
+    pio_sm_exec(pio, sm, pio_encode_set(pio_y, bits - 2));
+}
+
+static inline void pio_lsbj_out_program_init(PIO pio, uint sm, uint offset, uint data_pin, uint clock_pin_base, uint bits) {
+    pio_gpio_init(pio, data_pin);
+    pio_gpio_init(pio, clock_pin_base);
+    pio_gpio_init(pio, clock_pin_base + 1);
+
+    pio_sm_config sm_config = pio_lsbj_out_program_get_default_config(offset);
+
    sm_config_set_out_pins(&sm_config, data_pin, 1);
    sm_config_set_sideset_pins(&sm_config, clock_pin_base);
    sm_config_set_out_shift(&sm_config, false, true, (bits <= 16) ? 2 * bits : bits);
@@ -43,6 +43,41 @@ static inline pio_sm_config pio_i2s_out_program_get_default_config(uint offset)
 }
 #endif

+// ------------ //
+// pio_lsbj_out //
+// ------------ //
+
+#define pio_lsbj_out_wrap_target 0
+#define pio_lsbj_out_wrap 7
+
+static const uint16_t pio_lsbj_out_program_instructions[] = {
+    //     .wrap_target
+    0xa822, //  0: mov    x, y            side 1
+    0x7001, //  1: out    pins, 1         side 2
+    0x1841, //  2: jmp    x--, 1          side 3
+    0x7001, //  3: out    pins, 1         side 2
+    0xb822, //  4: mov    x, y            side 3
+    0x6001, //  5: out    pins, 1         side 0
+    0x0845, //  6: jmp    x--, 5          side 1
+    0x6001, //  7: out    pins, 1         side 0
+    //     .wrap
+};
+
+#if !PICO_NO_HARDWARE
+static const struct pio_program pio_lsbj_out_program = {
+    .instructions = pio_lsbj_out_program_instructions,
+    .length = 8,
+    .origin = -1,
+};
+
+static inline pio_sm_config pio_lsbj_out_program_get_default_config(uint offset) {
+    pio_sm_config c = pio_get_default_sm_config();
+    sm_config_set_wrap(&c, offset + pio_lsbj_out_wrap_target, offset + pio_lsbj_out_wrap);
+    sm_config_set_sideset(&c, 2, false, false);
+    return c;
+}
+#endif
+
 // ---------- //
 // pio_i2s_in //
 // ---------- //
@@ -92,6 +127,21 @@ static inline void pio_i2s_out_program_init(PIO pio, uint sm, uint offset, uint
    pio_sm_set_pins(pio, sm, 0); // clear pins
    pio_sm_exec(pio, sm, pio_encode_set(pio_y, bits - 2));
 }
+static inline void pio_lsbj_out_program_init(PIO pio, uint sm, uint offset, uint data_pin, uint clock_pin_base, uint bits) {
+    pio_gpio_init(pio, data_pin);
+    pio_gpio_init(pio, clock_pin_base);
+    pio_gpio_init(pio, clock_pin_base + 1);
+    pio_sm_config sm_config = pio_lsbj_out_program_get_default_config(offset);
+    sm_config_set_out_pins(&sm_config, data_pin, 1);
+    sm_config_set_sideset_pins(&sm_config, clock_pin_base);
+    sm_config_set_out_shift(&sm_config, false, true, (bits <= 16) ? 2 * bits : bits);
+    sm_config_set_fifo_join(&sm_config, PIO_FIFO_JOIN_TX);
+    pio_sm_init(pio, sm, offset, &sm_config);
+    uint pin_mask = (1u << data_pin) | (3u << clock_pin_base);
+    pio_sm_set_pindirs_with_mask(pio, sm, pin_mask, pin_mask);
+    pio_sm_set_pins(pio, sm, 0); // clear pins
+    pio_sm_exec(pio, sm, pio_encode_set(pio_y, bits - 2));
+}
 static inline void pio_i2s_in_program_init(PIO pio, uint sm, uint offset, uint data_pin, uint clock_pin_base, uint bits) {
    pio_gpio_init(pio, data_pin);
    pio_gpio_init(pio, clock_pin_base);
@@ -109,4 +159,3 @@ static inline void pio_i2s_in_program_init(PIO pio, uint sm, uint offset, uint d
 }

 #endif
-
@@ -28,7 +28,6 @@
 #include "ESP8266mDNS.h"
 #include "LEAmDNS_Priv.h"
 #include <LwipIntf.h>  // LwipIntf::stateUpCB()
-#include <LWIPMutex.h>  // LwipIntf::stateUpCB()
 #include <lwip/igmp.h>
 #include <lwip/prot/dns.h>

@@ -457,14 +457,14 @@ public:
                if (_creation) {
                    int rc = lfs_setattr(_fs->getFS(), _name.get(), 'c', (const void *)&_creation, sizeof(_creation));
                    if (rc < 0) {
-                        DEBUGV("Unable to set creation time on '%s' to %d\n", _name.get(), _creation);
+                        DEBUGV("Unable to set creation time on '%s' to %lld\n", _name.get(), _creation);
                    }
                }
                // Add metadata with last write time
                time_t now = _timeCallback();
                int rc = lfs_setattr(_fs->getFS(), _name.get(), 't', (const void *)&now, sizeof(now));
                if (rc < 0) {
-                    DEBUGV("Unable to set last write time on '%s' to %d\n", _name.get(), now);
+                    DEBUGV("Unable to set last write time on '%s' to %lld\n", _name.get(), now);
                }
            }
        }
@@ -0,0 +1,37 @@
+/*
+  This example plays a raw, headerless, mono 16b, 44.1 sample using the PWMAudio library on GPIO 1.
+
+  Released to the public domain by Earle F. Philhower, III <earlephilhower@yahoo.com>
+*/
+
+#include <PWMAudio.h>
+#include "wav.h"
+
+// The sample pointers
+const int16_t *start = (const int16_t *)out_raw;
+const int16_t *p = start;
+
+// Create the PWM audio device on GPIO 1.   Hook amp/speaker between GPIO1 and convenient GND.
+PWMAudio pwm(1);
+
+unsigned int count = 0;
+
+void cb() {
+  while (pwm.availableForWrite()) {
+    pwm.write(*p++);
+    count += 2;
+    if (count >= sizeof(out_raw)) {
+      count = 0;
+      p = start;
+    }
+  }
+}
+
+void setup() {
+  pwm.onTransmit(cb);
+  pwm.begin(44100);
+}
+
+void loop() {
+  /* noop, everything is done in the CB */
+}
@@ -0,0 +1,68 @@
+/*
+  This example plays a tune that alternates between left and right channels using a simple sine wave.
+
+  Released to the public domain by Earle F. Philhower, III <earlephilhower@yahoo.com>
+*/
+
+#include <PWMAudio.h>
+
+PWMAudio pwm(0, true); // GP0 = left, GP1 = right
+
+const int freq = 48000; // Output frequency for PWM
+
+int16_t al = 0;
+int16_t ar = 0;
+
+const int notes[] = { 784, 880, 698, 349, 523 };
+const int dly[] =   { 400, 500, 700, 500, 1000 };
+const int noteCnt = sizeof(notes) / sizeof(notes[0]);
+
+int freqL = 1;
+int freqR = 1;
+
+double sineTable[128]; // Precompute sine wave in 128 steps
+
+unsigned int cnt = 0;
+void cb() {
+  while (pwm.availableForWrite()) {
+    double now = ((double)cnt) / (double)freq;
+    int fl = freqL << 7; // Prescale by 128 to avoid FP math later on
+    int fr = freqR << 7; // Prescale by 128 to avoid FP math later on
+    pwm.write((uint16_t)(al * sineTable[(int)(now * fl) & 127]));
+    pwm.write((uint16_t)(ar * sineTable[(int)(now * fr) & 127]));
+    cnt++;
+  }
+}
+
+void setup() {
+  // Set up sine table for waveform generation
+  for (int i = 0; i < 128; i++) {
+    sineTable[i] = sin(i * 2.0 * 3.14159 / 128.0);
+  }
+  pwm.setBuffers(4, 32); // Give larger buffers since we're are 48khz sample rate
+  pwm.onTransmit(cb);
+  pwm.begin(freq);
+}
+
+void loop() {
+  delay(1000);
+
+  // Send it out on the LHS
+  ar = 0;
+  for (int i = 0; i < noteCnt; i++) {
+    freqL = notes[i];
+    al = 5000;
+    delay(dly[i]);
+  }
+  al = 0;
+  delay(1000);
+
+  // Hear reply on RHS
+  for (int i = 0; i < noteCnt; i++) {
+    freqR = notes[i] / 4;
+    ar = 15000;
+    delay(dly[i]);
+  }
+  ar = 0;
+  delay(3000);
+}
@@ -0,0 +1,26 @@
+#######################################
+# Syntax Coloring Map
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+PWMAudio	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+begin	KEYWORD2
+end	KEYWORD2
+
+setPin	KEYWORD2
+setFrequency	KEYWORD2
+setBuffers	KEYWORD2
+setStereo	KEYWORD2
+
+onTransmit	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################
@@ -0,0 +1,10 @@
+name=PWMAudio
+version=1.0
+author=Earle F. Philhower, III <earlephilhower@yahoo.com>
+maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
+sentence=Plays audio on a pin using the PWM hardware, no DAC required
+paragraph=Plays audio on a pin using the PWM hardware, no DAC required
+category=Communication
+url=http://github.com/earlephilhower/arduino-pico
+architectures=rp2040
+dot_a_linkage=true
@@ -0,0 +1,211 @@
+/*
+    PWMAudio
+    Plays a 16b audio stream on a user defined pin using PWM
+
+    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#include <Arduino.h>
+#include "PWMAudio.h"
+#include <hardware/pwm.h>
+
+
+PWMAudio::PWMAudio(pin_size_t pin, bool stereo) {
+    _running = false;
+    _pin = pin;
+    _freq = 48000;
+    _arb = nullptr;
+    _cb = nullptr;
+    _buffers = 8;
+    _bufferWords = 0;
+    _stereo = stereo;
+}
+
+PWMAudio::~PWMAudio() {
+    end();
+}
+
+bool PWMAudio::setBuffers(size_t buffers, size_t bufferWords) {
+    if (_running || (buffers < 3) || (bufferWords < 8)) {
+        return false;
+    }
+    _buffers = buffers;
+    _bufferWords = bufferWords;
+    return true;
+}
+
+bool PWMAudio::setPin(pin_size_t pin) {
+    if (_running) {
+        return false;
+    }
+    _pin = pin;
+    return true;
+}
+
+bool PWMAudio::setStereo(bool stereo) {
+    if (_running) {
+        return false;
+    }
+    _stereo = stereo;
+    return true;
+}
+
+bool PWMAudio::setFrequency(int newFreq) {
+    _freq = newFreq;
+
+    // Figure out the scale factor for PWM values
+    float fPWM = 65535.0 * _freq; // ideal
+
+    if (fPWM > clock_get_hz(clk_sys)) {
+        // Need to downscale the range to hit the frequency target
+        float pwmMax = (float) clock_get_hz(clk_sys) / (float) _freq;
+        _pwmScale = pwmMax;
+        fPWM = clock_get_hz(clk_sys);
+    } else {
+        _pwmScale = 1 << 16;
+    }
+
+    pwm_config c = pwm_get_default_config();
+    pwm_config_set_clkdiv(&c, clock_get_hz(clk_sys) / fPWM);
+    pwm_config_set_wrap(&c, _pwmScale);
+    pwm_init(pwm_gpio_to_slice_num(_pin), &c, _running);
+    gpio_set_function(_pin, GPIO_FUNC_PWM);
+    pwm_set_gpio_level(_pin, (0x8000 * _pwmScale) >> 16);
+    if (_stereo) {
+        gpio_set_function(_pin + 1, GPIO_FUNC_PWM);
+        pwm_set_gpio_level(_pin + 1, (0x8000 * _pwmScale) >> 16);
+    }
+
+    return true;
+}
+
+void PWMAudio::onTransmit(void(*fn)(void)) {
+    _cb = fn;
+    if (_running) {
+        _arb->setCallback(_cb);
+    }
+}
+
+bool PWMAudio::begin() {
+    if (_stereo && (_pin & 1)) {
+        // Illegal, need to have consecutive pins on the same PWM slice
+        Serial.printf("ERROR: PWMAudio stereo mode requires pin be even\n");
+        return false;
+    }
+
+    _running = true;
+    _wasHolding = false;
+
+    if (!_bufferWords) {
+        _bufferWords = 16;
+    }
+
+    setFrequency(_freq);
+
+    uint32_t ccAddr = PWM_BASE + PWM_CH0_CC_OFFSET + pwm_gpio_to_slice_num(_pin) * 20;
+
+    _arb = new AudioBufferManager(_buffers, _bufferWords, 0x80008000, OUTPUT, DMA_SIZE_32);
+    _arb->begin(pwm_get_dreq(pwm_gpio_to_slice_num(_pin)), (volatile void*)ccAddr);
+    _arb->setCallback(_cb);
+
+    return true;
+}
+
+void PWMAudio::end() {
+    if (_running) {
+        _running = false;
+        pinMode(_pin, OUTPUT);
+        if (_stereo) {
+            pinMode(_pin + 1, OUTPUT);
+        }
+        delete _arb;
+        _arb = nullptr;
+    }
+}
+
+int PWMAudio::available() {
+    return availableForWrite(); // Do what I mean, not what I say
+}
+
+int PWMAudio::read() {
+    return -1;
+}
+
+int PWMAudio::peek() {
+    return -1;
+}
+
+void PWMAudio::flush() {
+    if (_running) {
+        _arb->flush();
+    }
+}
+
+int PWMAudio::availableForWrite() {
+    if (!_running) {
+        return 0;
+    }
+    return _arb->available();
+}
+
+size_t PWMAudio::write(int16_t val, bool sync) {
+    if (!_running) {
+        return 0;
+    }
+    // Go from signed -32K...32K to unsigned 0...64K
+    uint32_t sample = (uint32_t)(val + 0x8000);
+    // Adjust to the real range
+    sample *= _pwmScale;
+    sample >>= 16;
+    if (!_stereo) {
+        // Duplicate sample since we don't care which PWM channel
+        sample = (sample & 0xffff) | (sample << 16);
+        return _arb->write(sample, sync);
+    } else {
+        if (_wasHolding) {
+            _holdWord = (_holdWord & 0xffff) | (sample << 16);
+            auto ret = _arb->write(_holdWord, sync);
+            if (ret) {
+                _wasHolding = false;
+            }
+            return ret;
+        } else {
+            _holdWord = sample;
+            _wasHolding = true;
+            return true;
+        }
+    }
+}
+
+size_t PWMAudio::write(const uint8_t *buffer, size_t size) {
+    // We can only write 16-bit chunks here
+    if (size & 0x1) {
+        return 0;
+    }
+    size_t writtenSize = 0;
+    int16_t *p = (int16_t *)buffer;
+    while (size) {
+        if (!write((int16_t)*p)) {
+            // Blocked, stop write here
+            return writtenSize;
+        } else {
+            p++;
+            size -= 4;
+            writtenSize += 4;
+        }
+    }
+    return writtenSize;
+}
@@ -0,0 +1,87 @@
+/*
+    PWMAudio
+    Plays a signed 16b audio stream on a user defined pin using PWM
+
+    Copyright (c) 2022 Earle F. Philhower, III <earlephilhower@yahoo.com>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+#include <Arduino.h>
+#include "AudioBufferManager.h"
+
+class PWMAudio : public Stream {
+public:
+    PWMAudio(pin_size_t pin = 0, bool stereo = false);
+    virtual ~PWMAudio();
+
+    bool setBuffers(size_t buffers, size_t bufferWords);
+    bool setFrequency(int newFreq);
+    bool setPin(pin_size_t pin);
+    bool setStereo(bool stereo = true);
+
+    bool begin(long sampleRate) {
+        setFrequency(sampleRate);
+        return begin();
+    }
+
+    bool begin();
+    void end();
+
+    // from Stream
+    virtual int available() override;
+    virtual int read() override;
+    virtual int peek() override;
+    virtual void flush() override;
+
+    // from Print (see notes on write() methods below)
+    virtual size_t write(const uint8_t *buffer, size_t size) override;
+    virtual int availableForWrite() override;
+
+    virtual size_t write(uint8_t x) override {
+        return write((int16_t) x, true);
+    }
+
+    // Write 16 bit value to port, user responsible for packing/alignment, etc.
+    size_t write(int16_t val, bool sync = true);
+    size_t write(int val, bool sync = true) {
+        return write((int16_t) val, sync);
+    }
+
+    // Note that these callback are called from **INTERRUPT CONTEXT** and hence
+    // should be in RAM, not FLASH, and should be quick to execute.
+    void onTransmit(void(*)(void));
+
+private:
+    pin_size_t _pin;
+    bool _stereo;
+
+    int _freq;
+
+    size_t _buffers;
+    size_t _bufferWords;
+
+    uint32_t _pwmScale;
+
+    bool _running;
+
+    bool _wasHolding;
+    uint32_t _holdWord;
+
+    void (*_cb)();
+
+    AudioBufferManager *_arb;
+};
@@ -5,6 +5,6 @@ maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
 sentence=Configures requests for OTA bootloader
 paragraph=Example repository for Ethernet drivers
 category=Device Control
-url=https://github.com/earlephilhower.arduino-pico
+url=https://github.com/earlephilhower/arduino-pico
 architectures=rp2040
 dot_a_linkage=true
@@ -178,7 +178,7 @@ void SPIClassRP2040::transfer(const void *txbuf, void *rxbuf, size_t count) {
 }

 void SPIClassRP2040::beginTransaction(SPISettings settings) {
-    DEBUGSPI("SPI::beginTransaction(clk=%d, bo=%s\n", _spis.getClockFreq(), (_spis.getBitOrder() == MSBFIRST) ? "MSB" : "LSB");
+    DEBUGSPI("SPI::beginTransaction(clk=%lu, bo=%s\n", _spis.getClockFreq(), (_spis.getBitOrder() == MSBFIRST) ? "MSB" : "LSB");
    if (_initted && settings == _spis) {
        DEBUGSPI("SPI: Reusing existing initted SPI\n");
    } else {
@@ -0,0 +1,92 @@
+// Simple logger with USB upload to PC
+// Uses SingleFileDrive to export an onboard LittleFS file to the computer
+// The PC can open/copy the file, and then the user can delete it to restart
+
+// Released to the public domain,  2022 - Earle F. Philhower, III
+
+#include <SingleFileDrive.h>
+#include <LittleFS.h>
+
+uint32_t cnt = 0;
+bool okayToWrite = true;
+
+// Make the CSV file and give it a simple header
+void headerCSV() {
+  File f = LittleFS.open("data.csv", "w");
+  f.printf("sample,millis,temp,rand\n");
+  f.close();
+  cnt = 0;
+}
+
+// Called when the USB stick connected to a PC and the drive opened
+// Note this is from a USB IRQ so no printing to SerialUSB/etc.
+void plug(uint32_t i) {
+  (void) i;
+  okayToWrite = false;
+}
+
+// Called when the USB is ejected or removed from a PC
+// Note this is from a USB IRQ so no printing to SerialUSB/etc.
+void unplug(uint32_t i) {
+  (void) i;
+  okayToWrite = true;
+}
+
+// Called when the PC tries to delete the single file
+// Note this is from a USB IRQ so no printing to SerialUSB/etc.
+void deleteCSV(uint32_t i) {
+  (void) i;
+  LittleFS.remove("data.csv");
+  headerCSV();
+}
+
+void setup() {
+  Serial.begin();
+  delay(5000);
+
+  LittleFS.begin();
+
+  // Set up the USB disk share
+  singleFileDrive.onDelete(deleteCSV);
+  singleFileDrive.onPlug(plug);
+  singleFileDrive.onUnplug(unplug);
+  singleFileDrive.begin("data.csv", "Recorded data from the Raspberry Pi Pico.csv");
+
+  // Find the last written data
+  File f = LittleFS.open("data.csv", "r");
+  if (!f || !f.size()) {
+    cnt = 1;
+    headerCSV();
+  } else {
+    if (f.size() > 2048) {
+      f.seek(f.size() - 1024);
+    }
+    do {
+      String s = f.readStringUntil('\n');
+      sscanf(s.c_str(), "%lu,", &cnt);
+    } while (f.available());
+    f.close();
+    cnt++;
+  }
+
+  Serial.printf("Starting acquisition at %lu\n", cnt);
+}
+
+void loop() {
+  float temp = analogReadTemp();
+  uint32_t hwrand = rp2040.hwrand32();
+  // Make sure the USB connect doesn't happen while we're writing!
+  noInterrupts();
+  if (okayToWrite) {
+    Serial.printf("Sampling...%lu\n", cnt);
+    // Don't want the USB to connect during an update!
+    File f = LittleFS.open("data.csv", "a");
+    if (f) {
+      f.printf("%lu,%lu,%f,%lu\n", cnt++, millis(), temp, hwrand);
+      f.close();
+    }
+  }
+  interrupts();
+
+  delay(10000);
+}
@@ -0,0 +1,22 @@
+#######################################
+# Syntax Coloring Map
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+SingleFileDrive	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+singleFileDrive KEYWORD1
+onDelete	KEYWORD1
+onPlug  KEYWORD1
+onUnplug        KEYWORD1
+
+#######################################
+# Constants (LITERAL1)
+#######################################
@@ -0,0 +1,10 @@
+name=SingleFileDrive
+version=1.0.0
+author=Earle F. Philhower, III <earlephilhower@yahoo.com>
+maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
+sentence=Allows using USB MSC (USB stick) to transfer an onboard flash file to a PC
+paragraph=Emulates a USB stick and presents a single file for users to copy over/erase
+category=Device Control
+url=https://github.com/earlephilhower/arduino-pico
+architectures=rp2040
+dot_a_linkage=true
@@ -0,0 +1,395 @@
+/*
+    SingleFileDrive - Emulates a USB stick for easy data transfer
+    Copyright (c) 2022 Earle F. Philhower, III.  All rights reserved.
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <SingleFileDrive.h>
+#include <LittleFS.h>
+#include <class/msc/msc.h>
+
+SingleFileDrive singleFileDrive;
+
+static const uint32_t _hddsize = (256 * 1024 * 1024); // 256MB
+static const uint32_t _hddsects = _hddsize / 512;
+
+// Ensure we are logged in to the USB framework
+void __USBInstallMassStorage() {
+    /* dummy */
+}
+
+SingleFileDrive::SingleFileDrive() {
+}
+
+SingleFileDrive::~SingleFileDrive() {
+    end();
+}
+
+void SingleFileDrive::onDelete(void (*cb)(uint32_t), uint32_t cbData) {
+    _cbDelete = cb;
+    _cbDeleteData = cbData;
+}
+
+void SingleFileDrive::onPlug(void (*cb)(uint32_t), uint32_t cbData) {
+    _cbPlug = cb;
+    _cbPlugData = cbData;
+}
+
+void SingleFileDrive::onUnplug(void (*cb)(uint32_t), uint32_t cbData) {
+    _cbUnplug = cb;
+    _cbUnplugData = cbData;
+}
+
+bool SingleFileDrive::begin(const char *localFile, const char *dosFile) {
+    if (_started) {
+        return false;
+    }
+    _localFile = strdup(localFile);
+    _dosFile = strdup(dosFile);
+    _started = true;
+    return true;
+}
+
+void SingleFileDrive::end() {
+    _started = false;
+    free(_localFile);
+    free(_dosFile);
+    _localFile = nullptr;
+    _dosFile = nullptr;
+}
+
+void SingleFileDrive::bootSector(char buff[512]) {
+    // 256MB FAT16 stolen from mkfs.fat
+    // dd if=/dev/zero of=/tmp/fat.bin bs=1M seek=255 count=1
+    // mkfs.fat -F 16 -r 16 -n PICODISK -i 12345678 -s 128 -m ':(' /tmp/fat.bin
+    const uint8_t hdr[] = {
+        0xeb, 0x3c, 0x90, 0x6d, 0x6b, 0x66, 0x73, 0x2e, 0x66, 0x61, 0x74, 0x00,
+        0x02, 0x80, 0x80, 0x00, 0x02, 0x00, 0x08, 0x00, 0x00, 0xf8, 0x80, 0x00,
+        0x20, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00,
+        0x80, 0x00, 0x29, 0x78, 0x56, 0x34, 0x12, 0x50, 0x49, 0x43, 0x4f, 0x44,
+        0x49, 0x53, 0x4b, 0x20, 0x20, 0x20, 0x46, 0x41, 0x54, 0x31, 0x36, 0x20,
+        0x20, 0x20, 0x0e, 0x1f, 0xbe, 0x5b, 0x7c, 0xac, 0x22, 0xc0, 0x74, 0x0b,
+        0x56, 0xb4, 0x0e, 0xbb, 0x07, 0x00, 0xcd, 0x10, 0x5e, 0xeb, 0xf0, 0x32,
+        0xe4, 0xcd, 0x16, 0xcd, 0x19, 0xeb, 0xfe, 0x3a, 0x28, 0x0d, 0x0a, 0x00
+    };
+    memset(buff, 0, 512);
+    memcpy(buff, hdr, sizeof(hdr));
+    buff[0x1fe] = 0x55;
+    buff[0x1ff] = 0xff;
+}
+
+static char _toLegalFATChar(char c) {
+    const char *odds = "!#$%&'()-@^_`{}~";
+    c = toupper(c);
+    if (((c >= '0') && (c <= '9')) || ((c >= 'A') && (c <= 'Z')) || strchr(odds, c)) {
+        return c;
+    } else {
+        return '~';
+    }
+}
+
+void SingleFileDrive::directorySector(char buff[512]) {
+    const uint8_t lbl[] = {
+        0x50, 0x49, 0x43, 0x4f, 0x44, 0x49, 0x53, 0x4b, 0x20, 0x20, 0x20, 0x08, 0x00, 0x00, 0xac, 0x56,
+        0x82, 0x55, 0x82, 0x55, 0x00, 0x00, 0xac, 0x56, 0x82, 0x55
+    }; //, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+    memset(buff, 0, 512);
+    memcpy(buff, lbl, sizeof(lbl));
+    buff += 32; // Skip the just-set label
+
+    // Create a legal 11-char UPPERCASE FILENAME WITH 0x20 PAD
+    char SFN[11];
+    memset(SFN, ' ', 11);
+    for (int i = 0; (i < 8) && _dosFile[i] && (_dosFile[i] != '.'); i++) {
+        SFN[i] = _toLegalFATChar(_dosFile[i]);
+    }
+    char *dot = _dosFile + strlen(_dosFile) - 1;
+    while ((dot >= _dosFile) && (*dot != '.')) {
+        dot--;
+    }
+    if (*dot == '.') {
+        dot++;
+        for (int i = 0; (i < 3) && dot[i]; i++) {
+            SFN[8 + i] = _toLegalFATChar(dot[i]);
+        }
+    }
+    uint8_t chksum = 0; // for LFN
+    for (int i = 0; i < 11; i++) {
+        chksum = (chksum >> 1) + (chksum << 7) + SFN[i];
+    }
+
+    // Create LFN structure
+    int entries = (strlen(_dosFile) + 12) / 13; // round up
+    for (int i = 0; i < entries; i++) {
+        *buff++ = (entries - i) | (i == 0 ? 0x40 : 0);
+        const char *partname = _dosFile + 13 * (entries - i - 1);
+        for (int j = 0; j < 13; j++) {
+            uint16_t u;
+            if (j > (int)strlen(partname)) {
+                u = 0xffff;
+            } else {
+                u = partname[j] & 0xff;
+            }
+            *buff++ = u & 0xff;
+            *buff++ = (u >> 8) & 0xff;
+            if (j == 4) {
+                *buff++ = 0x0f; // LFN ATTR
+                *buff++ = 0;
+                *buff++ = chksum;
+            } else if (j == 10) {
+                *buff++ = 0;
+                *buff++ = 0;
+            }
+        }
+    }
+
+    // Create SFN
+    memset(buff, 0, 32);
+    for (int i = 0; i < 11; i++) {
+        buff[i] = SFN[i];
+    }
+    buff[0x0b] = 0x20; // ATTR = Archive
+    // Ignore creation data/time, etc.
+    buff[0x1a] = 0x03; // Starting cluster 3
+    File f = LittleFS.open(_localFile, "r");
+    int size = f.size();
+    f.close();
+    buff[0x1c] = size & 255;
+    buff[0x1d] = (size >> 8) & 255;
+    buff[0x1e] = (size >> 16) & 255; // 16MB or smaller
+}
+
+void SingleFileDrive::fatSector(char fat[512]) {
+    memset(fat, 0, 512);
+    fat[0x00] = 0xff;
+    fat[0x01] = 0xf8;
+    fat[0x02] = 0xff;
+    fat[0x03] = 0xff;
+    int cluster = 3;
+    File f = LittleFS.open(_localFile, "r");
+    int size = f.size();
+    f.close();
+    while (size > 65536) {
+        fat[cluster * 2] = (cluster + 1) & 0xff;
+        fat[cluster * 2 + 1] = ((cluster + 1) >> 8) & 0xff;
+        cluster++;
+        size -= 65536;
+    }
+    fat[cluster * 2] = 0xff;
+    fat[cluster * 2 + 1] = 0xff;
+}
+
+// Invoked to determine max LUN
+extern "C" uint8_t tud_msc_get_maxlun_cb(void) {
+    return 1;
+}
+
+// Invoked when received SCSI_CMD_INQUIRY
+// Application fill vendor id, product id and revision with string up to 8, 16, 4 characters respectively
+extern "C" void tud_msc_inquiry_cb(uint8_t lun, uint8_t vendor_id[8], uint8_t product_id[16], uint8_t product_rev[4]) {
+    (void) lun;
+
+    const char vid[] = "PicoDisk";
+    const char pid[] = "Mass Storage";
+    const char rev[] = "1.0";
+
+    memcpy(vendor_id, vid, strlen(vid));
+    memcpy(product_id, pid, strlen(pid));
+    memcpy(product_rev, rev, strlen(rev));
+}
+
+bool SingleFileDrive::testUnitReady() {
+    return _started;
+}
+
+// Invoked when received Test Unit Ready command.
+// return true allowing host to read/write this LUN e.g SD card inserted
+extern "C" bool tud_msc_test_unit_ready_cb(uint8_t lun) {
+    (void) lun;
+
+    return singleFileDrive.testUnitReady();
+}
+
+// Invoked when received SCSI_CMD_READ_CAPACITY_10 and SCSI_CMD_READ_FORMAT_CAPACITY to determine the disk size
+// Application update block count and block size
+extern "C" void tud_msc_capacity_cb(uint8_t lun, uint32_t* block_count, uint16_t* block_size) {
+    (void) lun;
+    *block_count = _hddsects;
+    *block_size  = 512;
+}
+
+
+// Callback invoked when received READ10 command.
+// Copy disk's data to buffer (up to bufsize) and return number of copied bytes.
+extern "C" int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize) {
+    (void) lun;
+    return singleFileDrive.read10(lba, offset, buffer, bufsize);
+}
+
+int32_t SingleFileDrive::read10(uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize) {
+    if (!_started || (lba >= _hddsects)) {
+        return -1;
+    }
+
+    uint32_t toread = bufsize;
+    uint8_t *curbuff = (uint8_t *)buffer;
+
+    while (bufsize > 0) {
+        if (lba == 0) {
+            bootSector(_sectBuff);
+        } else if ((lba == 128) || (lba == 256)) {
+            fatSector(_sectBuff);
+        } else if (lba == 384) {
+            directorySector(_sectBuff);
+        } else if (lba >= 640) {
+            File f = LittleFS.open(_localFile, "r");
+            f.seek((lba - 640) * 512);
+            f.read((uint8_t*)_sectBuff, 512);
+            f.close();
+        } else {
+            memset(_sectBuff, 0, sizeof(_sectBuff));
+        }
+
+        uint32_t cplen = 512 - offset;
+        if (bufsize < cplen) {
+            cplen = bufsize;
+        }
+        memcpy(curbuff, _sectBuff + offset, cplen);
+        curbuff += cplen;
+        offset = 0;
+        lba++;
+        bufsize -= cplen;
+    }
+
+    return toread;
+}
+
+extern "C" bool tud_msc_is_writable_cb(uint8_t lun) {
+    (void) lun;
+
+    return true;
+}
+
+// Callback invoked when received WRITE10 command.
+// Process data in buffer to disk's storage and return number of written bytes
+extern "C" int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize) {
+    (void) lun;
+    return singleFileDrive.write10(lba, offset, buffer, bufsize);
+}
+
+int32_t SingleFileDrive::write10(uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize) {
+    if (!_started || (lba >= _hddsects)) {
+        return -1;
+    }
+
+    uint32_t addr = lba * 512 + offset;
+    uint32_t hotspot = 384 * 512 + 0x20;
+    if ((addr > hotspot) || (addr + bufsize < hotspot)) {
+        // Did not try and erase the file entry, ignore
+        return bufsize;
+    }
+    int off = hotspot - addr;
+    uint8_t *ptr = (uint8_t *)buffer;
+    ptr += off;
+    if (*ptr == 0xe5) {
+        if (_cbDelete) {
+            _cbDelete(_cbDeleteData);
+        }
+    }
+
+    return bufsize;
+}
+
+extern "C" bool tud_msc_set_sense(uint8_t lun, uint8_t sense_key, uint8_t add_sense_code, uint8_t add_sense_qualifier);
+
+// Callback invoked when received an SCSI command not in built-in list below
+// - READ_CAPACITY10, READ_FORMAT_CAPACITY, INQUIRY, MODE_SENSE6, REQUEST_SENSE
+// - READ10 and WRITE10 has their own callbacks
+extern "C" int32_t tud_msc_scsi_cb(uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize) {
+    const int SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL = 0x1E;
+    const int SCSI_CMD_START_STOP_UNIT              = 0x1B;
+    const int SCSI_SENSE_ILLEGAL_REQUEST = 0x05;
+
+    void const* response = NULL;
+    int32_t resplen = 0;
+
+    // most scsi handled is input
+    bool in_xfer = true;
+    scsi_start_stop_unit_t const * start_stop = (scsi_start_stop_unit_t const *) scsi_cmd;
+    switch (scsi_cmd[0]) {
+    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
+        // Host is about to read/write etc ... better not to disconnect disk
+        if (scsi_cmd[4] & 1) {
+            singleFileDrive.plug();
+        }
+        resplen = 0;
+        break;
+    case SCSI_CMD_START_STOP_UNIT:
+        // Host try to eject/safe remove/poweroff us. We could safely disconnect with disk storage, or go into lower power
+        if (!start_stop->start && start_stop->load_eject) {
+            singleFileDrive.unplug();
+        } else if (start_stop->start && start_stop->load_eject) {
+            singleFileDrive.plug();
+        }
+        resplen = 0;
+        break;
+    default:
+        // Set Sense = Invalid Command Operation
+        tud_msc_set_sense(lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
+        // negative means error -> tinyusb could stall and/or response with failed status
+        resplen = -1;
+        break;
+    }
+
+    // return resplen must not larger than bufsize
+    if (resplen > bufsize) {
+        resplen = bufsize;
+    }
+
+    if (response && (resplen > 0)) {
+        if (in_xfer) {
+            memcpy(buffer, response, resplen);
+        } else {
+            // SCSI output
+        }
+    }
+
+    return resplen;
+}
+
+void SingleFileDrive::plug() {
+    if (_started && _cbPlug) {
+        _cbPlug(_cbPlugData);
+    }
+}
+
+void SingleFileDrive::unplug() {
+    if (_started && _cbUnplug) {
+        _cbUnplug(_cbUnplugData);
+    }
+}
+
+// Callback invoked on start/stop
+extern "C" bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject) {
+    (void) lun;
+    (void) power_condition;
+    if (start && load_eject) {
+        singleFileDrive.plug();
+    } else if (!start && load_eject) {
+        singleFileDrive.unplug();
+    }
+    return true;
+}
@@ -0,0 +1,65 @@
+/*
+    SingleFileDrive - Emulates a USB stick for easy data transfer
+    Copyright (c) 2022 Earle F. Philhower, III.  All rights reserved.
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+
+#include <Arduino.h>
+
+class SingleFileDrive {
+public:
+    SingleFileDrive();
+    ~SingleFileDrive();
+
+    bool begin(const char *localFile, const char *dosFile);
+    void end();
+
+    void onDelete(void (*cb)(uint32_t), uint32_t cbData = 0);
+    void onPlug(void (*cb)(uint32_t), uint32_t cbData = 0);
+    void onUnplug(void (*cb)(uint32_t), uint32_t cbData = 0);
+
+    // Only for internal TinyUSB callback use
+    bool testUnitReady();
+    int32_t read10(uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize);
+    int32_t write10(uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize);
+    void plug();;
+    void unplug();
+
+private:
+    void bootSector(char buff[512]);
+    void directorySector(char buff[512]);
+    void fatSector(char buff[512]);
+
+private:
+    bool _started = false;
+    char *_localFile = nullptr;
+    char *_dosFile = nullptr;
+
+    char _sectBuff[512]; // Read sector region
+
+    void (*_cbDelete)(uint32_t) = nullptr;
+    uint32_t _cbDeleteData = 0;
+
+    void (*_cbPlug)(uint32_t) = nullptr;
+    uint32_t _cbPlugData = 0;
+
+    void (*_cbUnplug)(uint32_t) = nullptr;
+    uint32_t _cbUnplugData = 0;
+};
+
+extern SingleFileDrive singleFileDrive;
@@ -129,7 +129,7 @@ bool UpdaterClass::begin(size_t size, int command) {
    _command = command;

 #ifdef DEBUG_UPDATER
-    DEBUG_UPDATER.printf_P(PSTR("[begin] _startAddress:     0x%08X (%d)\n"), _startAddress, _startAddress);
+    DEBUG_UPDATER.printf_P(PSTR("[begin] _startAddress:     0x%08lX (%lu)\n"), _startAddress, _startAddress);
    DEBUG_UPDATER.printf_P(PSTR("[begin] _size:             0x%08zX (%zd)\n"), _size, _size);
 #endif

@@ -188,7 +188,7 @@ bool UpdaterClass::end(bool evenIfRemaining) {
            _fp.read((uint8_t *)&sigLen, sizeof(uint32_t));
        }
 #ifdef DEBUG_UPDATER
-        DEBUG_UPDATER.printf_P(PSTR("[Updater] sigLen: %d\n"), sigLen);
+        DEBUG_UPDATER.printf_P(PSTR("[Updater] sigLen: %lu\n"), sigLen);
 #endif
        if (sigLen != expectedSigLen) {
            _setError(UPDATE_ERROR_SIGN);
@@ -276,7 +276,7 @@ bool UpdaterClass::end(bool evenIfRemaining) {
        picoOTA.addFile("firmware.bin");
        picoOTA.commit();
 #ifdef DEBUG_UPDATER
-        DEBUG_UPDATER.printf_P(PSTR("Staged: address:0x%08X, size:0x%08zX\n"), _startAddress, _size);
+        DEBUG_UPDATER.printf_P(PSTR("Staged: address:0x%08lX, size:0x%08zX\n"), _startAddress, _size);
 #endif
    }

@@ -32,6 +32,7 @@
 #include <WiFiClient.h>
 #include <WebServer.h>
 #include <LEAmDNS.h>
+#include <StreamString.h>

 #ifndef STASSID
 #define STASSID "your-ssid"
@@ -43,18 +44,18 @@ const char *password = STAPSK;

 WebServer server(80);

-const int led = 13;
+const int led = LED_BUILTIN;

 void handleRoot() {
+  static int cnt = 0;
  digitalWrite(led, 1);
-  char temp[400];
  int sec = millis() / 1000;
  int min = sec / 60;
  int hr = min / 60;

-  snprintf(temp, 400,
-
-           "<html>\
+  StreamString temp;
+  temp.reserve(500); // Preallocate a large chunk to avoid memory fragmentation
+  temp.printf("<html>\
  <head>\
    <meta http-equiv='refresh' content='5'/>\
    <title>Pico-W Demo</title>\
@@ -65,11 +66,11 @@ void handleRoot() {
  <body>\
    <h1>Hello from the Pico W!</h1>\
    <p>Uptime: %02d:%02d:%02d</p>\
+    <p>Free Memory: %d</p>\
+    <p>Page Count: %d</p>\
    <img src=\"/test.svg\" />\
  </body>\
-</html>",
-
-           hr, min % 60, sec % 60);
+</html>", hr, min % 60, sec % 60, rp2040.getFreeHeap(), ++cnt);
  server.send(200, "text/html", temp);
  digitalWrite(led, 0);
 }
@@ -0,0 +1,149 @@
+#include <WiFi.h>
+#include <WiFiClient.h>
+#include <WebServer.h>
+#include <LEAmDNS.h>
+
+#ifndef STASSID
+#define STASSID "your-ssid"
+#define STAPSK "your-password"
+#endif
+
+const char* ssid = STASSID;
+const char* password = STAPSK;
+
+WebServer server(80);
+
+const int led = LED_BUILTIN;
+
+void handleRoot() {
+  digitalWrite(led, 1);
+  server.send(200, "text/plain", "hello from pico w!\r\n");
+  digitalWrite(led, 0);
+}
+
+void handleNotFound() {
+  digitalWrite(led, 1);
+  String message = "File Not Found\n\n";
+  message += "URI: ";
+  message += server.uri();
+  message += "\nMethod: ";
+  message += (server.method() == HTTP_GET) ? "GET" : "POST";
+  message += "\nArguments: ";
+  message += server.args();
+  message += "\n";
+  for (uint8_t i = 0; i < server.args(); i++) {
+    message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
+  }
+  server.send(404, "text/plain", message);
+  digitalWrite(led, 0);
+}
+
+void setup(void) {
+  pinMode(led, OUTPUT);
+  digitalWrite(led, 0);
+  Serial.begin(115200);
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+  Serial.println("");
+
+  // Wait for connection
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println("");
+  Serial.print("Connected to ");
+  Serial.println(ssid);
+  Serial.print("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  if (MDNS.begin("picow")) {
+    Serial.println("MDNS responder started");
+  }
+
+  server.on("/", handleRoot);
+
+  server.on("/inline", []() {
+    server.send(200, "text/plain", "this works as well");
+  });
+
+  server.on("/gif", []() {
+    static const uint8_t gif[] = {
+      0x47, 0x49, 0x46, 0x38, 0x37, 0x61, 0x10, 0x00, 0x10, 0x00, 0x80, 0x01,
+      0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0x2c, 0x00, 0x00, 0x00, 0x00,
+      0x10, 0x00, 0x10, 0x00, 0x00, 0x02, 0x19, 0x8c, 0x8f, 0xa9, 0xcb, 0x9d,
+      0x00, 0x5f, 0x74, 0xb4, 0x56, 0xb0, 0xb0, 0xd2, 0xf2, 0x35, 0x1e, 0x4c,
+      0x0c, 0x24, 0x5a, 0xe6, 0x89, 0xa6, 0x4d, 0x01, 0x00, 0x3b
+    };
+    char gif_colored[sizeof(gif)];
+    memcpy_P(gif_colored, gif, sizeof(gif));
+    // Set the background to a random set of colors
+    gif_colored[16] = millis() % 256;
+    gif_colored[17] = millis() % 256;
+    gif_colored[18] = millis() % 256;
+    server.send(200, "image/gif", gif_colored, sizeof(gif_colored));
+  });
+
+  server.onNotFound(handleNotFound);
+
+  /////////////////////////////////////////////////////////
+  // Hook examples
+
+  server.addHook([](const String & method, const String & url, WiFiClient * client, WebServer::ContentTypeFunction contentType) {
+    (void)method;       // GET, PUT, ...
+    (void)url;          // example: /root/myfile.html
+    (void)client;       // the webserver tcp client connection
+    (void)contentType;  // contentType(".html") => "text/html"
+    Serial.printf("A useless web hook has passed\n");
+    return WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  server.addHook([](const String&, const String & url, WiFiClient*, WebServer::ContentTypeFunction) {
+    if (url.startsWith("/fail")) {
+      Serial.printf("An always failing web hook has been triggered\n");
+      return WebServer::CLIENT_MUST_STOP;
+    }
+    return WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  server.addHook([](const String&, const String & url, WiFiClient * client, WebServer::ContentTypeFunction) {
+    if (url.startsWith("/dump")) {
+      Serial.printf("The dumper web hook is on the run\n");
+
+      // Here the request is not interpreted, so we cannot for sure
+      // swallow the exact amount matching the full request+content,
+      // hence the tcp connection cannot be handled anymore by the
+      auto last = millis();
+      while ((millis() - last) < 500) {
+        char buf[32];
+        size_t len = client->read((uint8_t*)buf, sizeof(buf));
+        if (len > 0) {
+          Serial.printf("(<%d> chars)", (int)len);
+          Serial.write(buf, len);
+          last = millis();
+        }
+      }
+      // Two choices: return MUST STOP and webserver will close it
+      //                       (we already have the example with '/fail' hook)
+      // or                  IS GIVEN and webserver will forget it
+      // trying with IS GIVEN and storing it on a dumb WiFiClient.
+      // check the client connection: it should not immediately be closed
+      // (make another '/dump' one to close the first)
+      Serial.printf("\nTelling server to forget this connection\n");
+      static WiFiClient forgetme = *client;  // stop previous one if present and transfer client refcounter
+      return WebServer::CLIENT_IS_GIVEN;
+    }
+    return WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  // Hook examples
+  /////////////////////////////////////////////////////////
+
+  server.begin();
+  Serial.println("HTTP server started");
+}
+
+void loop(void) {
+  server.handleClient();
+  MDNS.update();
+}
@@ -249,20 +249,32 @@ void HTTPServer::httpHandleClient() {
        case HC_WAIT_READ:
            // Wait for data from client to become available
            if (_currentClient->available()) {
-                if (_parseRequest(_currentClient)) {
-                    // because HTTP_MAX_SEND_WAIT is expressed in milliseconds,
-                    // it must be divided by 1000
+                switch (_parseRequest(_currentClient)) {
+                case CLIENT_REQUEST_CAN_CONTINUE:
+                    // Because HTTP_MAX_SEND_WAIT is expressed in milliseconds, it must be divided by 1000
                    _currentClient->setTimeout(HTTP_MAX_SEND_WAIT / 1000);
                    _contentLength = CONTENT_LENGTH_NOT_SET;
                    _handleRequest();
-
-                    // Fix for issue with Chrome based browsers: https://github.com/espressif/arduino-esp32/issues/3652
-                    //           if (_currentClient->connected()) {
-                    //             _currentStatus = HC_WAIT_CLOSE;
-                    //             _statusChange = millis();
-                    //             keepCurrentClient = true;
-                    //           }
-                }
+                /* fallthrough */
+                case CLIENT_REQUEST_IS_HANDLED:
+                    if (_currentClient->connected() || _currentClient->available()) {
+                        _currentStatus = HC_WAIT_CLOSE;
+                        _statusChange = millis();
+                        keepCurrentClient = true;
+                    } else {
+                        log_v("webserver: peer has closed after served\n");
+                    }
+                    break;
+                case CLIENT_MUST_STOP:
+                    log_v("Close client\n");
+                    _currentClient->stop();
+                    break;
+                case CLIENT_IS_GIVEN:
+                    // client must not be stopped but must not be handled here anymore
+                    // (example: tcp connection given to websocket)
+                    log_v("Give client\n");
+                    break;
+                } // switch _parseRequest()
            } else { // !_currentClient->available()
                if (millis() - _statusChange <= HTTP_MAX_DATA_WAIT) {
                    keepCurrentClient = true;
@@ -280,7 +292,10 @@ void HTTPServer::httpHandleClient() {
    }

    if (!keepCurrentClient) {
-        _currentClient = nullptr;
+        if (_currentClient) {
+            delete _currentClient;
+            _currentClient = nullptr;
+        }
        _currentStatus = HC_NONE;
        _currentUpload.reset();
    }
@@ -48,6 +48,8 @@ enum HTTPAuthMethod { BASIC_AUTH, DIGEST_AUTH };
 #define CONTENT_LENGTH_UNKNOWN ((size_t) -1)
 #define CONTENT_LENGTH_NOT_SET ((size_t) -2)

+#define WEBSERVER_HAS_HOOK 1
+
 class HTTPServer;

 typedef struct {
@@ -183,6 +185,25 @@ public:
        return _currentClient->write(file);
    }

+    // Hook
+    enum ClientFuture { CLIENT_REQUEST_CAN_CONTINUE, CLIENT_REQUEST_IS_HANDLED, CLIENT_MUST_STOP, CLIENT_IS_GIVEN };
+    typedef String(*ContentTypeFunction)(const String&);
+    using HookFunction = std::function<ClientFuture(const String& method, const String& url, WiFiClient* client, ContentTypeFunction contentType)>;
+    void addHook(HookFunction hook) {
+        if (_hook) {
+            auto previousHook = _hook;
+            _hook = [previousHook, hook](const String & method, const String & url, WiFiClient * client, ContentTypeFunction contentType) {
+                auto whatNow = previousHook(method, url, client, contentType);
+                if (whatNow == CLIENT_REQUEST_CAN_CONTINUE) {
+                    return hook(method, url, client, contentType);
+                }
+                return whatNow;
+            };
+        } else {
+            _hook = hook;
+        }
+    }
+
 protected:
    virtual size_t _currentClientWrite(const char* b, size_t l) {
        return _currentClient->write(b, l);
@@ -193,7 +214,7 @@ protected:
    void _addRequestHandler(RequestHandler* handler);
    void _handleRequest();
    void _finalizeResponse();
-    bool _parseRequest(WiFiClient* client);
+    ClientFuture _parseRequest(WiFiClient* client);
    void _parseArguments(String data);
    static String _responseCodeToString(int code);
    bool _parseForm(WiFiClient* client, String boundary, uint32_t len);
@@ -249,4 +270,6 @@ protected:
    String           _snonce;  // Store noance and opaque for future comparison
    String           _sopaque;
    String           _srealm;  // Store the Auth realm between Calls
+
+    HookFunction     _hook;
 };
@@ -78,7 +78,7 @@ static char* readBytesWithTimeout(WiFiClient* client, size_t maxLength, size_t&
    return buf;
 }

-bool HTTPServer::_parseRequest(WiFiClient* client) {
+HTTPServer::ClientFuture HTTPServer::_parseRequest(WiFiClient* client) {
    // Read the first line of HTTP request
    String req = client->readStringUntil('\r');
    client->readStringUntil('\n');
@@ -93,7 +93,7 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
    int addr_end = req.indexOf(' ', addr_start + 1);
    if (addr_start == -1 || addr_end == -1) {
        log_e("Invalid request: %s", req.c_str());
-        return false;
+        return CLIENT_MUST_STOP;
    }

    String methodStr = req.substring(0, addr_start);
@@ -110,6 +110,13 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
    _chunked = false;
    _clientContentLength = 0;  // not known yet, or invalid

+    if (_hook) {
+        auto whatNow = _hook(methodStr, url, client, mime::getContentType);
+        if (whatNow != CLIENT_REQUEST_CAN_CONTINUE) {
+            return whatNow;
+        }
+    }
+
    HTTPMethod method = HTTP_ANY;
    size_t num_methods = sizeof(_http_method_str) / sizeof(const char *);
    for (size_t i = 0; i < num_methods; i++) {
@@ -120,7 +127,7 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
    }
    if (method == HTTP_ANY) {
        log_e("Unknown HTTP Method: %s", methodStr.c_str());
-        return false;
+        return CLIENT_MUST_STOP;
    }
    _currentMethod = method;

@@ -186,7 +193,7 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
            char* plainBuf = readBytesWithTimeout(client, _clientContentLength, plainLength, HTTP_MAX_POST_WAIT);
            if ((int)plainLength < (int)_clientContentLength) {
                free(plainBuf);
-                return false;
+                return CLIENT_MUST_STOP;
            }
            if (_clientContentLength > 0) {
                if (isEncoded) {
@@ -214,7 +221,7 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
            // it IS a form
            _parseArguments(searchStr);
            if (!_parseForm(client, boundaryStr, _clientContentLength)) {
-                return false;
+                return CLIENT_MUST_STOP;
            }
        }
    } else {
@@ -249,7 +256,7 @@ bool HTTPServer::_parseRequest(WiFiClient* client) {
    log_v("Request: %s", url.c_str());
    log_v(" Arguments: %s", searchStr.c_str());

-    return true;
+    return CLIENT_REQUEST_CAN_CONTINUE;
 }

 bool HTTPServer::_collectHeader(const char* headerName, const char* headerValue) {
@@ -113,7 +113,7 @@ void loop() {
  client.setTrustAnchors(&cert);
  fetchURL(&client, host, port, path);
  finish = millis();
-  Serial.printf("Total time: %dms\n", finish - start);
+  Serial.printf("Total time: %lums\n", finish - start);

  BearSSL::Session session;
  client.setSession(&session);
@@ -122,21 +122,21 @@ void loop() {
  client.setTrustAnchors(&cert);
  fetchURL(&client, host, port, path);
  finish = millis();
-  Serial.printf("Total time: %dms\n", finish - start);
+  Serial.printf("Total time: %lums\n", finish - start);

  Serial.printf("Connecting with the just initialized session...");
  start = millis();
  client.setTrustAnchors(&cert);
  fetchURL(&client, host, port, path);
  finish = millis();
-  Serial.printf("Total time: %dms\n", finish - start);
+  Serial.printf("Total time: %lums\n", finish - start);

  Serial.printf("Connecting again with the initialized session...");
  start = millis();
  client.setTrustAnchors(&cert);
  fetchURL(&client, host, port, path);
  finish = millis();
-  Serial.printf("Total time: %dms\n", finish - start);
+  Serial.printf("Total time: %lums\n", finish - start);

  delay(10000);  // Avoid DDOSing github
 }
@@ -76,7 +76,7 @@ void fetchURL(BearSSL::WiFiClientSecure *client, const char *host, const uint16_
    } while (millis() < to);
  }
  client->stop();
-  Serial.printf("BSSL stack used: %d\n-------\n\n", stack_thunk_get_max_usage());
+  Serial.printf("BSSL stack used: %lu\n-------\n\n", stack_thunk_get_max_usage());
 }

 void fetchNoConfig() {
@@ -24,7 +24,7 @@ const char *encToString(uint8_t enc) {

 void loop() {
  delay(5000);
-  Serial.printf("Beginning scan at %d\n", millis());
+  Serial.printf("Beginning scan at %lu\n", millis());
  auto cnt = WiFi.scanNetworks();
  if (!cnt) {
    Serial.printf("No networks found\n");
@@ -34,7 +34,7 @@ void loop() {
    for (auto i = 0; i < cnt; i++) {
      uint8_t bssid[6];
      WiFi.BSSID(i, bssid);
-      Serial.printf("%32s %5s %17s %2d %4d\n", WiFi.SSID(i), encToString(WiFi.encryptionType(i)), macToString(bssid), WiFi.channel(i), WiFi.RSSI(i));
+      Serial.printf("%32s %5s %17s %2d %4ld\n", WiFi.SSID(i), encToString(WiFi.encryptionType(i)), macToString(bssid), WiFi.channel(i), WiFi.RSSI(i));
    }
  }
  Serial.printf("\n--- Sleeping ---\n\n\n");
@@ -42,6 +42,7 @@ gatewayIP	KEYWORD2
 SSID	KEYWORD2
 BSSID		KEYWORD2
 RSSI	KEYWORD2
+channel	KEYWORD2
 encryptionType	KEYWORD2
 beginPacket	KEYWORD2
 endPacket	KEYWORD2
@@ -56,7 +57,8 @@ beginEnterprise	KEYWORD2
 setHostname	KEYWORD2
 end	KEYWORD2
 getTime	KEYWORD2
-lowPowerMode	KEYWORD2
+aggressiveLowPowerMode	KEYWORD2
+defaultLowPowerMode	KEYWORD2
 noLowPowerMode	KEYWORD2
 ping	KEYWORD2
 beginMulticast	KEYWORD2
@@ -3,8 +3,6 @@
 #include "wl_definitions.h"
 #include "wl_types.h"

-#include "LWIPMutex.h"
-
 #include "WiFiClass.h"
 #include "WiFiClient.h"
 #include "WiFiServer.h"
@@ -44,17 +44,20 @@ const char* WiFiClass::firmwareVersion() {
    return PICO_SDK_VERSION_STRING;
 }

-void WiFiClass::mode(_wifiModeESP m) {
+void WiFiClass::mode(WiFiMode_t m) {
    _calledESP = true;
    switch (m) {
-    case WIFI_OFF:
+    case WiFiMode_t::WIFI_OFF:
        end();
        break;
-    case WIFI_AP:
-        _modeESP = WIFI_AP;
+    case WiFiMode_t::WIFI_AP:
+        _modeESP = WiFiMode_t::WIFI_AP;
        break;
-    case WIFI_STA:
-        _modeESP = WIFI_STA;
+    case WiFiMode_t::WIFI_STA:
+        _modeESP = WiFiMode_t::WIFI_STA;
+        break;
+    case WiFiMode_t::WIFI_AP_STA:
+        _modeESP = WiFiMode_t::WIFI_STA;
        break;
    }
 }
@@ -86,7 +89,7 @@ int WiFiClass::begin(const char* ssid, const char *passphrase) {

    _ssid = ssid;
    _password = passphrase;
-    _wifi.setSSID(ssid);
+    _wifi.setSSID(_ssid.c_str());
    _wifi.setPassword(passphrase);
    _wifi.setTimeout(_timeout);
    _wifi.setSTA();
@@ -96,6 +99,7 @@ int WiFiClass::begin(const char* ssid, const char *passphrase) {
    if (!_wifi.begin()) {
        return WL_IDLE_STATUS;
    }
+    noLowPowerMode();
    // Enable CYW43 event debugging (make sure Debug Port is set)
    //cyw43_state.trace_flags = 0xffff;
    while (!_calledESP && ((millis() - start < (uint32_t)2 * _timeout)) && !connected()) {
@@ -123,7 +127,7 @@ uint8_t WiFiClass::beginAP(const char *ssid, const char* passphrase) {

    _ssid = ssid;
    _password = passphrase;
-    _wifi.setSSID(ssid);
+    _wifi.setSSID(_ssid.c_str());
    _wifi.setPassword(passphrase);
    _wifi.setTimeout(_timeout);
    _wifi.setAP();
@@ -131,6 +135,7 @@ uint8_t WiFiClass::beginAP(const char *ssid, const char* passphrase) {
    if (!_wifi.begin()) {
        return WL_IDLE_STATUS;
    }
+    noLowPowerMode();
    IPAddress gw = _wifi.gatewayIP();
    if (!gw.isSet()) {
        gw = IPAddress(192, 168, 42, 1);
@@ -234,7 +239,7 @@ const char *WiFiClass::getHostname() {

    return: one value of wl_status_t enum
 */
-int WiFiClass::disconnect(void) {
+int WiFiClass::disconnect(bool wifi_off __unused) {
    if (_dhcpServer) {
        dhcp_server_deinit(_dhcpServer);
        free(_dhcpServer);
@@ -300,7 +305,7 @@ IPAddress WiFiClass::gatewayIP() {

    return: ssid string
 */
-const char* WiFiClass::SSID() {
+const String &WiFiClass::SSID() {
    return _ssid;
 }

@@ -311,11 +316,33 @@ const char* WiFiClass::SSID() {
    return: pointer to uint8_t array with length WL_MAC_ADDR_LENGTH
 */
 uint8_t* WiFiClass::BSSID(uint8_t* bssid) {
-    // TODO - driver does not return this?!
-    memset(bssid, 0xee, WL_MAC_ADDR_LENGTH);
+#ifndef CYW43_IOCTL_GET_BSSID
+#define CYW43_IOCTL_GET_BSSID ( (uint32_t)23 * 2 )
+#endif
+
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_BSSID, WL_MAC_ADDR_LENGTH, bssid, CYW43_ITF_STA);
+    } else {
+        memset(bssid, 0, WL_MAC_ADDR_LENGTH);
+    }
    return bssid;
 }

+int WiFiClass::channel() {
+#ifndef CYW43_IOCTL_GET_CHANNEL
+#define CYW43_IOCTL_GET_CHANNEL 0x3a
+#endif
+
+    int32_t channel;
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_CHANNEL, sizeof channel, (uint8_t *)&channel, CYW43_ITF_STA);
+    } else {
+        channel = -1;
+    }
+    return channel;
+}
+
+
 /*
    Return the current RSSI /Received Signal Strength in dBm)
    associated with the network
@@ -323,8 +350,17 @@ uint8_t* WiFiClass::BSSID(uint8_t* bssid) {
    return: signed value
 */
 int32_t WiFiClass::RSSI() {
-    // TODO - driver does not return this?!
-    return 0;
+#ifndef CYW43_IOCTL_GET_RSSI
+#define CYW43_IOCTL_GET_RSSI 0xFE
+#endif
+
+    int32_t rssi;
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_RSSI, sizeof rssi, (uint8_t *)&rssi, CYW43_ITF_STA);
+    } else {
+        rssi = -255;
+    }
+    return rssi;
 }

 /*
@@ -365,7 +401,7 @@ int WiFiClass::_scanCB(void *env, const cyw43_ev_scan_result_t *result) {

    return: Number of discovered networks
 */
-int8_t WiFiClass::scanNetworks() {
+int8_t WiFiClass::scanNetworks(bool async) {
    cyw43_wifi_scan_options_t scan_options;
    memset(&scan_options, 0, sizeof(scan_options));
    _scan.clear();
@@ -378,11 +414,27 @@ int8_t WiFiClass::scanNetworks() {
    if (err) {
        return 0;
    }
-    uint32_t now = millis();
-    while (cyw43_wifi_scan_active(&cyw43_state) && (millis() - now < 10000)) {
-        delay(10);
+    if (!async) {
+        uint32_t now = millis();
+        while (cyw43_wifi_scan_active(&cyw43_state) && (millis() - now < 10000)) {
+            delay(10);
+        }
+        return _scan.size();
+    } else {
+        return -1;
    }
-    return _scan.size();
+}
+
+int8_t WiFiClass::scanComplete() {
+    if (cyw43_wifi_scan_active(&cyw43_state)) {
+        return -1;
+    } else {
+        return _scan.size();
+    }
+}
+
+void WiFiClass::scanDelete() {
+    _scan.clear();
 }

 /*
@@ -515,14 +567,19 @@ unsigned long WiFiClass::getTime() {
    return millis();
 }

-void WiFiClass::lowPowerMode() {
+void WiFiClass::aggressiveLowPowerMode() {
    cyw43_wifi_pm(&cyw43_state, CYW43_AGGRESSIVE_PM);
 }

-void WiFiClass::noLowPowerMode() {
+void WiFiClass::defaultLowPowerMode() {
    cyw43_wifi_pm(&cyw43_state, CYW43_DEFAULT_PM);
 }

+// The difference between the default CYW43_DEFAULT_PM (0xA11142) and not low power (0xA11140) is that it changed from "Powersave mode on specified interface with High throughput" to "No Powersave mode". All other parameters stayed the same.
+void WiFiClass::noLowPowerMode() {
+    cyw43_wifi_pm(&cyw43_state, 0xA11140);
+}
+
 int WiFiClass::ping(const char* hostname, uint8_t ttl) {
    IPAddress ip;
    if (!hostByName(hostname, ip)) {
@@ -35,7 +35,7 @@

 typedef void(*FeedHostProcessorWatchdogFuncPointer)();

-typedef enum { WIFI_STA, WIFI_AP, WIFI_OFF } _wifiModeESP; // For ESP8266 compatibility
+typedef enum { WIFI_OFF = 0, WIFI_STA = 1, WIFI_AP = 2, WIFI_AP_STA = 3 } WiFiMode_t; // For ESP8266 compatibility

 class WiFiClass {
 public:
@@ -46,7 +46,18 @@ public:
    */
    static const char* firmwareVersion();

-    void mode(_wifiModeESP m); // For ESP8266 compatibility
+    void mode(WiFiMode_t m); // For ESP8266 compatibility
+
+    WiFiMode_t getMode() {
+        if (_wifiHWInitted) {
+            if (_apMode) {
+                return WiFiMode_t::WIFI_AP;
+            } else {
+                return WiFiMode_t::WIFI_STA;
+            }
+        }
+        return WiFiMode_t::WIFI_OFF;
+    };

    /*  Start WiFi connection for OPEN networks

@@ -138,7 +149,7 @@ public:
    }

    String softAPSSID() {
-        return String(SSID());
+        return SSID();
    }


@@ -205,7 +216,7 @@ public:

        return: one value of wl_status_t enum
    */
-    int disconnect(void);
+    int disconnect(bool wifi_off = false);

    void end(void);

@@ -249,7 +260,7 @@ public:

        return: ssid string
    */
-    const char* SSID();
+    const String &SSID();

    /*
        Return the current BSSID associated with the network.
@@ -267,6 +278,10 @@ public:
    */
    int32_t RSSI();

+
+    /* Return the current network channel */
+    int channel();
+
    /*
        Return the Encryption Type associated with the network

@@ -277,9 +292,23 @@ public:
    /*
        Start scan WiFi networks available

+        param async: whether to perform asynchronous scan
+
        return: Number of discovered networks
    */
-    int8_t scanNetworks();
+    int8_t scanNetworks(bool async = false);
+
+    /*
+        Return number of scanned WiFi networks
+
+        return: Number of discovered networks
+    */
+    int8_t scanComplete();
+
+    /*
+        Delete scan results
+    */
+    void scanDelete();

    /*
        Return the SSID discovered during the network scan.
@@ -339,7 +368,8 @@ public:

    unsigned long getTime();

-    void lowPowerMode();
+    void aggressiveLowPowerMode();
+    void defaultLowPowerMode();
    void noLowPowerMode();

    int ping(const char* hostname, uint8_t ttl = 128);
@@ -352,9 +382,9 @@ public:
    void feedWatchdog();

 private:
-    int _timeout = 10000;
-    const char * _ssid = nullptr;
-    const char * _password = nullptr;
+    int _timeout = 15000;
+    String _ssid;
+    String _password;
    bool _wifiHWInitted = false;
    bool _apMode = false;

@@ -367,7 +397,7 @@ private:

    // ESP compat
    bool _calledESP = false; // Should we behave like the ESP8266 for connect?
-    _wifiModeESP _modeESP = WIFI_STA;
+    WiFiMode_t _modeESP = WIFI_STA;
 };

 extern WiFiClass WiFi;
--- a/Show More
+++ b/Show More