nanoFramework.Iot.Device.Es7210

ES7210 - 4-channel audio ADC (microphone capture codec)

The Everest Semiconductor ES7210 is a 4-channel high-performance audio ADC used on many ESP32 audio boards (ESP32-S3-Korvo, ESP-BOX, and the M5Stack CoreS3). It digitizes analog microphone inputs and outputs the captured audio as an I2S PCM stream.

This binding covers the I2C control plane only. It configures the codec (clocking, microphone selection, gain, mute and power state) for a two-microphone (MIC1 + MIC2) capture setup in slave mode. The captured PCM audio samples are streamed out over I2S using System.Device.I2s and are not handled by this binding.

The register sequences are ported from the Espressif esp_codec_dev component and should be validated should be validated on hardware other than the CoreS3. The default I2C address is 0x40.

Documentation

• ES7210 is configured over I2C (control) and streams captured audio over I2S (data).
• On the M5Stack CoreS3 the ES7210 (microphones) and the AW88298 (speaker) share the same internal I2C bus and I2S data lines.
• Espressif esp_codec_dev component - the source of the register sequences (ES7210 driver source).
• M5Stack CoreS3 documentation and the Espressif CoreS3 board support package.

Audio path on the M5Stack CoreS3

On the CoreS3 the internal bus and the microphone power are gated by the on-board AXP2101 PMIC and AW9523 IO expander (pin 2). The sample powers these up over I2C before configuring the codec; for a fuller implementation use the Iot.Device.Axp2101 / Iot.Device.Aw9523x bindings or the M5Stack CoreS3 board package.

Usage

using Iot.Device.Es7210;
using nanoFramework.Hardware.Esp32;
using System;
using System.Device.I2c;
using System.Device.I2s;

// Setup the M5Stack CoreS3 internal I2C bus (SDA = GPIO12, SCL = GPIO11).
Configuration.SetPinFunction(12, DeviceFunction.I2C1_DATA);
Configuration.SetPinFunction(11, DeviceFunction.I2C1_CLOCK);

I2cConnectionSettings settings = new I2cConnectionSettings(1, Es7210.DefaultI2cAddress);
I2cDevice i2cDevice = new I2cDevice(settings);

Es7210 adc = new Es7210(i2cDevice);

// Setup the ESP32 I2S receiver (MCLK = GPIO0, BCLK = GPIO34, WS = GPIO33, DSIN = GPIO14).
Configuration.SetPinFunction(34, DeviceFunction.I2S1_BCK);
Configuration.SetPinFunction(33, DeviceFunction.I2S1_WS);
Configuration.SetPinFunction(14, DeviceFunction.I2S1_MDATA_IN);
Configuration.SetPinFunction(0, DeviceFunction.I2S1_MCK);

I2sDevice i2s = new I2sDevice(new I2sConnectionSettings(1)
{
    Mode = I2sMode.Master | I2sMode.Rx,
    CommunicationFormat = I2sCommunicationFormat.I2S,
    ChannelFormat = I2sChannelFormat.RightLeft,
    BitsPerSample = I2sBitsPerSample.Bit16,
    SampleRate = 16_000,
});

// Start the clocks, then configure the codec.
SpanByte warmup = new byte[256];
i2s.Read(warmup);

adc.Initialize();
adc.Start();
adc.MicGain = Es7210.MaxMicGain;

// Select which microphones to capture: MIC1 only, MIC2 only, or both (the default).
adc.SelectedMicrophones = Microphones.Microphone1 | Microphones.Microphone2;

// Read interleaved stereo 16-bit PCM with i2s.Read(...) to obtain microphone samples.