Add M5.In_I2C init

Author: YloraX

README.md

@@ -6,10 +6,30 @@
 
 **Module Audio** is an audio-interaction expansion module for M5Stack, built on the ES8388 audio codec solution. It offers dual 3.5 mm jacks (one TRS jack for microphone input only, one TRRS jack for both microphone input and headphone output) to fulfill various recording and stereo playback needs. An onboard STM32G030F6P6 microcontroller handles TRRS jack insertion detection and drives WS2812C RGB LEDs. Register configuration enables automatic switching between CTIA (American) and OMTP (International) wiring standards, ensuring compatibility with most headsets featuring integrated microphones. This module is ideal for smart voice, interactive art, educational entertainment, portable recording, and other audio applications.
 
+## I2C bus selection
+
+Module Audio supports both the M5Unified internal I2C bus and the Arduino `Wire` bus. Call `M5.begin()` before using `M5.In_I2C`.
+
+```cpp
+M5ModuleAudio audio;
+
+M5.begin();
+audio.begin(M5.In_I2C);
+```
+
+Existing `Wire` code remains supported:
+
+```cpp
+M5ModuleAudio audio;
+
+M5.begin();
+audio.begin(Wire);
+```
+
 ## Related Link
 
 - [Document & Datasheet](https://docs.m5stack.com/en/module/Module-Audio)
 
 ## License
 
-- [MIT](https://github.com/m5stack/Module-Audio/blob/main/LICENSE)
+- [MIT](https://github.com/m5stack/Module-Audio/blob/main/LICENSE)

examples/i2sloopback/i2sloopback.ino

@@ -25,7 +25,7 @@ void setup()
     cfg.serial_baudrate = 115200;
     M5.begin(cfg);
 
-    if (!device.begin(Wire)) {
+    if (!device.begin(M5.In_I2C)) {
         while (1) {
             Serial.println("Module Audio not found");
             delay(1000);

examples/player_sd/player_sd.ino

@@ -26,7 +26,7 @@ void setup()
     cfg.serial_baudrate = 115200;
     M5.begin(cfg);
 
-    if (!device.begin(Wire)) {
+    if (!device.begin(M5.In_I2C)) {
         while (1) {
             Serial.println("Module Audio not found");
             delay(1000);

examples/player_spiffs/player_spiffs.ino

@@ -21,7 +21,7 @@ void setup()
     cfg.serial_baudrate = 115200;
     M5.begin(cfg);
 
-    if (!device.begin(Wire)) {
+    if (!device.begin(M5.In_I2C)) {
         while (1) {
             Serial.println("Module Audio not found");
             delay(1000);

src/M5Module_Audio.cpp

@@ -35,12 +35,20 @@ uint32_t sample_rate_to_hz(es_sample_rate_t rate)
 }  // namespace
 
 #if USE_NEW_I2S_API
-M5ModuleAudio::M5ModuleAudio() : _wire(nullptr), _sda(0), _scl(0), _addr(I2C_ADDR), es8388(nullptr)
+M5ModuleAudio::M5ModuleAudio()
+    : _wire(nullptr), _m5_i2c(nullptr), _i2c_speed(400000), _sda(0), _scl(0), _addr(I2C_ADDR), es8388(nullptr)
 {
 }
 #else
 M5ModuleAudio::M5ModuleAudio(i2s_port_t i2s_num)
-    : _wire(nullptr), _sda(0), _scl(0), _addr(I2C_ADDR), es8388(nullptr), i2s_num(i2s_num)
+    : _wire(nullptr),
+      _m5_i2c(nullptr),
+      _i2c_speed(400000),
+      _sda(0),
+      _scl(0),
+      _addr(I2C_ADDR),
+      es8388(nullptr),
+      i2s_num(i2s_num)
 {
 }
 #endif
@@ -72,10 +80,29 @@ bool M5ModuleAudio::begin(TwoWire &wire, uint8_t addr)
     return begin(wire, sda, scl, addr, 400000, 44100, mck, di, ws, do_, bck);
 }
 
+bool M5ModuleAudio::begin(m5::I2C_Class &i2c, uint8_t addr, uint32_t speed)
+{
+#if defined(CONFIG_IDF_TARGET_ESP32S3)
+    uint8_t bck = M5.getPin(m5::pin_name_t::mbus_pin24);  // SCLK
+    uint8_t mck = M5.getPin(m5::pin_name_t::mbus_pin22);  // MCLK
+#else
+    uint8_t bck = M5.getPin(m5::pin_name_t::mbus_pin22);  // SCLK
+    uint8_t mck = M5.getPin(m5::pin_name_t::mbus_pin24);  // MCLK
+#endif
+    uint8_t di  = M5.getPin(m5::pin_name_t::mbus_pin26);
+    uint8_t ws  = M5.getPin(m5::pin_name_t::mbus_pin21);  // LRCK
+    uint8_t do_ = M5.getPin(m5::pin_name_t::mbus_pin23);
+    printf("I2C port: %d, SDA: %d, SCL: %d\n", i2c.getPort(), i2c.getSDA(), i2c.getSCL());
+    printf("I2S MCK: %d, DI: %d, WS: %d, DO: %d, BCK: %d\n", mck, di, ws, do_, bck);
+    return begin(i2c, addr, speed, 44100, mck, di, ws, do_, bck);
+}
+
 bool M5ModuleAudio::begin(TwoWire &wire, uint8_t sda, uint8_t scl, uint8_t addr, uint32_t speed)
 {
     _i2s_initialized = false;
     _wire            = &wire;
+    _m5_i2c          = nullptr;
+    _i2c_speed       = speed;
     _sda             = sda;
     _scl             = scl;
     _addr            = addr;
@@ -101,10 +128,12 @@ bool M5ModuleAudio::begin(TwoWire &wire, uint8_t sda, uint8_t scl, uint8_t addr,
 bool M5ModuleAudio::begin(TwoWire &wire, uint8_t sda, uint8_t scl, uint8_t addr, uint32_t speed, int sample_rate,
                           int i2s_mck, int i2s_di, int i2s_ws, int i2s_do, int i2s_bck)
 {
-    _wire = &wire;
-    _sda  = sda;
-    _scl  = scl;
-    _addr = addr;
+    _wire      = &wire;
+    _m5_i2c    = nullptr;
+    _i2c_speed = speed;
+    _sda       = sda;
+    _scl       = scl;
+    _addr      = addr;
 
     // Store IO pins
     _i2s_mck = i2s_mck;
@@ -141,6 +170,40 @@ bool M5ModuleAudio::begin(TwoWire &wire, uint8_t sda, uint8_t scl, uint8_t addr,
     return true;
 }
 
+bool M5ModuleAudio::begin(m5::I2C_Class &i2c, uint8_t addr, uint32_t speed, int sample_rate, int i2s_mck, int i2s_di,
+                          int i2s_ws, int i2s_do, int i2s_bck)
+{
+    _wire      = nullptr;
+    _m5_i2c    = &i2c;
+    _i2c_speed = speed;
+    _sda       = i2c.getSDA();
+    _scl       = i2c.getSCL();
+    _addr      = addr;
+
+    _i2s_mck = i2s_mck;
+    _i2s_bck = i2s_bck;
+    _i2s_ws  = i2s_ws;
+    _i2s_do  = i2s_do;
+    _i2s_di  = i2s_di;
+
+    if (!i2c.isEnabled() || !i2c.scanID(addr, speed)) {
+        ESP_LOGI(TAG, "Module Audio controller not found on M5Unified I2C bus");
+        return false;
+    }
+
+    if (!i2s_driver_init(sample_rate)) {
+        ESP_LOGI(TAG, "I2S driver initialization failed");
+        return false;
+    }
+
+    if (!es8388_codec_init()) {
+        ESP_LOGI(TAG, "ES8388 codec initialization failed");
+        return false;
+    }
+
+    return setMicGain(MIC_GAIN_0DB);
+}
+
 void M5ModuleAudio::setMICStatus(audio_mic_t status)
 {
     uint8_t reg = MICROPHONE_STATUS;
@@ -249,7 +312,11 @@ bool M5ModuleAudio::es8388_codec_init()
         es8388 = nullptr;
     }
 
-    es8388 = new ES8388(_wire, _sda, _scl);
+    if (_m5_i2c != nullptr) {
+        es8388 = new ES8388(_m5_i2c, _i2c_speed);
+    } else {
+        es8388 = new ES8388(_wire, _sda, _scl, _i2c_speed);
+    }
     if (!es8388->init()) {
         ESP_LOGI(TAG, "Failed to initialize ES8388 codec");
         return false;
@@ -675,6 +742,15 @@ bool M5ModuleAudio::play(const uint8_t *buffer, int size)
 
 void M5ModuleAudio::writeBytes(uint8_t addr, uint8_t reg, uint8_t *buffer, uint8_t length)
 {
+    if (_m5_i2c != nullptr) {
+        _m5_i2c->writeRegister(addr, reg, buffer, length, _i2c_speed);
+        return;
+    }
+
+    if (_wire == nullptr) {
+        return;
+    }
+
     _wire->beginTransmission(addr);
     _wire->write(reg);
     for (int i = 0; i < length; i++) {
@@ -700,6 +776,18 @@ void M5ModuleAudio::writeBytes(uint8_t addr, uint8_t reg, uint8_t *buffer, uint8
 
 void M5ModuleAudio::readBytes(uint8_t addr, uint8_t reg, uint8_t *buffer, uint8_t length)
 {
+    if (_m5_i2c != nullptr) {
+        if (!_m5_i2c->readRegister(addr, reg, buffer, length, _i2c_speed)) {
+            memset(buffer, 0, length);
+        }
+        return;
+    }
+
+    if (_wire == nullptr) {
+        memset(buffer, 0, length);
+        return;
+    }
+
     uint8_t index = 0;
     _wire->beginTransmission(addr);
     _wire->write(reg);

src/M5Module_Audio.h

@@ -102,6 +102,21 @@ class M5ModuleAudio {
 
     bool begin(TwoWire& wire, uint8_t addr = I2C_ADDR);
 
+    /**
+     * @brief Initializes Module Audio using an M5Unified I2C bus and automatic board pin mapping.
+     * @param i2c M5Unified I2C bus (for example, M5.In_I2C).
+     * @param addr Module Audio controller I2C address.
+     * @param speed I2C clock speed in Hz.
+     * @return bool True if I2C, I2S, and ES8388 initialization succeeded.
+     */
+    bool begin(m5::I2C_Class& i2c, uint8_t addr = I2C_ADDR, uint32_t speed = 400000);
+
+    /**
+     * @brief Initializes Module Audio using an M5Unified I2C bus and explicit I2S pins.
+     */
+    bool begin(m5::I2C_Class& i2c, uint8_t addr, uint32_t speed, int sample_rate, int i2s_mck, int i2s_di, int i2s_ws,
+               int i2s_do, int i2s_bck);
+
     /**
      * @brief Set microphone/LINE input status
      * @param status Audio input state (AUDIO_MIC_CLOSE/AUDIO_MIC_OPEN)
@@ -352,6 +367,8 @@ class M5ModuleAudio {
 
 private:
     TwoWire* _wire;
+    m5::I2C_Class* _m5_i2c;
+    uint32_t _i2c_speed;
     uint8_t _sda, _scl;
     uint8_t _addr;
 

src/es8388.cpp

@@ -5,18 +5,28 @@
  */
 
 #include "es8388.hpp"
+#include <M5Unified.h>
 
 ES8388::ES8388(TwoWire* wire, uint8_t sda, uint8_t scl, uint32_t speed)
+    : _wire(wire), _m5_i2c(nullptr), _scl(scl), _sda(sda), _speed(speed)
 {
-    _wire  = wire;
-    _sda   = sda;
-    _scl   = scl;
-    _speed = speed;
     _wire->begin(_sda, _scl, _speed);
 }
 
+ES8388::ES8388(m5::I2C_Class* i2c, uint32_t speed) : _wire(nullptr), _m5_i2c(i2c), _scl(-1), _sda(-1), _speed(speed)
+{
+}
+
 bool ES8388::writeBytes(uint8_t reg, uint8_t data)
 {
+    if (_m5_i2c != nullptr) {
+        return _m5_i2c->writeRegister8(ES8388_ADDR, reg, data, _speed);
+    }
+
+    if (_wire == nullptr) {
+        return false;
+    }
+
     _wire->beginTransmission(ES8388_ADDR);
     _wire->write(reg);
     _wire->write(data);
@@ -35,6 +45,14 @@ bool ES8388::writeBytes(uint8_t reg, uint8_t data)
 
 bool ES8388::readBytes(uint8_t reg, uint8_t& data)
 {
+    if (_m5_i2c != nullptr) {
+        return _m5_i2c->readRegister(ES8388_ADDR, reg, &data, 1, _speed);
+    }
+
+    if (_wire == nullptr) {
+        return false;
+    }
+
     bool ret = false;
     _wire->beginTransmission(ES8388_ADDR);
     _wire->write(reg);
@@ -312,4 +330,4 @@ bool ES8388::setSampleRate(es_sample_rate_t rate)
     res &= writeBytes(ES8388_ADCCONTROL5, adcFsRatio & 0x1F);
     res &= writeBytes(ES8388_DACCONTROL2, dacFsRatio & 0x1F);
     return res;
-}
+}

src/es8388.hpp

@@ -10,6 +10,10 @@
 #include <Arduino.h>
 #include <Wire.h>
 
+namespace m5 {
+class I2C_Class;
+}
+
 // #define ES8388_DEBUG Serial  // This macro definition can be annotated without sending and receiving data prints
 //         Define the serial port you want to use, e.g., Serial1 or Serial2
 #if defined ES8388_DEBUG
@@ -392,6 +396,13 @@ class ES8388 {
      */
     ES8388(TwoWire* wire, uint8_t sda = -1, uint8_t scl = -1, uint32_t speed = 400000L);
 
+    /**
+     * @brief Constructs ES8388 codec controller using an M5Unified I2C bus
+     * @param i2c M5Unified I2C bus pointer (for example, &M5.In_I2C)
+     * @param speed I2C clock speed in Hz (default 400kHz)
+     */
+    ES8388(m5::I2C_Class* i2c, uint32_t speed = 400000L);
+
     /**
      * @brief Reads all codec registers into a buffer
      * @return Pointer to 53-byte array containing register values (0x00-0x34)
@@ -487,6 +498,7 @@ class ES8388 {
 
 private:
     TwoWire* _wire;
+    m5::I2C_Class* _m5_i2c;
     uint8_t _scl;
     uint8_t _sda;
     uint32_t _speed;
@@ -510,4 +522,4 @@ class ES8388 {
     bool readBytes(uint8_t reg, uint8_t& data);
 };
 
-#endif
+#endif