TLV320AIC31xx codec configuration utility

This library allows configuration of the Texas Instruments TLV320AIC31xx codecs on Arduino platforms. It has been tested with the TLV320AIC3100 on a ACEV-1B eval board (i2c test points and ground hooked up to an esp32 dev kit board). It does not support all codec functions yet (like mic AGC) and likely has some rough edges.

Host simulation

Host simulation uses a register map instead of i2c. This is initialized with the default values as per datasheet. Just run make to compile the codec_simulator binary from examples/main.cpp. Any register operations will be printed to stdout:

INFO Set Page: 1
Read  Reg:031 (Binary: 0b00000100) Value: 0x04 AIC31XX_HPDRIVER
Write Reg:031 (Binary: 0b11000100) Value: 0xc4 AIC31XX_HPDRIVER
Read  Reg:040 (Binary: 0b00000010) Value: 0x02 AIC31XX_HPLGAIN
Write Reg:040 (Binary: 0b00000110) Value: 0x06 AIC31XX_HPLGAIN

PIO

The platformio.ini should be self-explantory. I2C pins are defined as build flags.

Example

The setup method in examples/main.cpp shows all required calls to enable DAC, headphone, speakers, clocking via PLL from BLCK for 44,1kHz 16bit.

Integration in platform.io project

Usage of this library is straightforward. Add the library to the lib_deps:

lib_deps=
	https://github.com/haklein/tlv320aic31xx.git

Include the header file and instantiate the class:

#include "tlv320aic31xx_codec.h"

TLV320AIC31xx codec(&Wire);

Call the begin() method to reset the codec after setting up TwoWire and then configure the codec as per requirements:

    Wire.begin(SDA_PIN, SCL_PIN);
    codec.begin(); // initialize library and soft reset codec (hard reset via reset pin is also required!) 
    sleep(1);
    codec.setWordLength(AIC31XX_WORD_LEN_16BITS);

    // next 6 lines configure clock for 44.1kHz 2c 16bit, generation of MCLK from BCLK via PLL
    // TI provides a spreadsheet to derive valid values for different sample rates etc.
    // https://www.ti.com/tool/download/SLAR163/01.00.00.00

    codec.setCLKMUX(AIC31XX_PLL_CLKIN_BCLK, AIC31XX_CODEC_CLKIN_PLL);
    codec.setPLL(1, 2, 32, 0); // uint8_t pll_p, uint8_t pll_r, uint8_t pll_j, uint16_t pll_d
    codec.setNDACVal(8);
    codec.setNDACPower(true);
    codec.setMDACVal(2);
    codec.setMDACPower(true);
    [...]

Usage notes

Headphone detection

When generating the MCLK from BCLK (as per example above) the clock for the timers need to be generated internally. This is required for debouncing and the headset detection doesn't work without the timers. There is no high level method for this yet but it can be set for the time being via:

    codec.modifyRegister(AIC31XX_TIMERDIVIDER, AIC31XX_TIMER_SELECT_MASK, 0);

Detection can be configured to trigger the GPIO output and enabled via:

      codec.enableHeadsetDetect();
      codec.setHSDetectInt1(true);

This can then be handled via ISR (assuming CONFIG_TLV320AIC3100_INT would be defined to the connected GPIO pin):

 pinMode(CONFIG_TLV320AIC3100_INT, INPUT);
 attachInterrupt(CONFIG_TLV320AIC3100_INT, codec_isr, RISING);

The assumed codec_isr method would then likely set a flag for the main loop where the headset state can be read. Please be aware that the codec won't send any further interrupts until the interrupt flag register has been read:

  if (codec.readRegister(AIC31XX_INTRDACFLAG) & AIC31XX_HSPLUG) { // bit 4 is set on headset related interrupts
    Serial.println("AIC31XX: Headset plug interrupt triggered");
  }

The headset state can be polled with the isHeadsetDetected() method:

  if (codec.isHeadsetDetected()) {
    Serial.println("AIC31XX: Headset detected");
    codec.setHeadphoneMute(false); // unmute hp
    codec.setSpeakerMute(true); // mute class d speaker amp
    // [...]
  }

Arduino audio tools

The codec works great with the arduino audio tools I2SStream:

    i2s = new I2SStream;

    I2SConfig config = i2s->defaultConfig(RXTX_MODE);

    config.sample_rate = 44100; // sr, c & bps need to match the codec clock configuration for BCLK->MCLK PLL
    config.channels = 2;
    config.bits_per_sample = 16;
    config.pin_bck = CONFIG_I2S_BCK_PIN; // define your i2s pins
    config.pin_ws = CONFIG_I2S_LRCK_PIN;
    config.pin_data = CONFIG_I2S_DATA_PIN;
    config.pin_data_rx = CONFIG_I2S_DATA_IN_PIN;

    config.buffer_size=1024;

    i2s->begin(config);