I2S Audio~

This feature is not included in precompiled binaries

When compiling your build add the following to user_config_override.h: To use it you must compile your build. Add the following to user_config_override.h:

#ifndef USE_I2S_AUDIO
#define USE_I2S_AUDIO                             // Add support for I2S audio output
// #define USE_I2S_NO_DAC                         // Add support for transistor-based output without DAC
// #define USE_I2S_LSB                            // Add support for LSBJ chips, e.g. TM8211/PT8211
// #define USE_I2S_WEBRADIO                       // Add support for MP3 web radio streaming (only on ESP32 with PSRAM)
// #define USE_I2S_SAY_TIME                       // Add support for english speaking clock
// #define USE_I2S_RTTTL                          // Add support for Rtttl playback
#endif

// USE_M5STACK_CORE2, USE_TTGO_WATCH and ESP32S3_BOX already include I2S_AUDIO

Also requires lib_extra_dirs = lib/lib_audio, lib/libesp32_audio added to the build environment

I2S (Inter-IC Sound) is a serial, synchronous communication protocol that is usually used for transmitting audio data between two digital audio devices.

Audio Output~

I2S DAC

For audio output an I2S digital audio decoder (DAC) board is required. It is recommended to use an external DAC

I2S DAC	ESP32	ESP8266 (fixed pins)
BCLK	I2S_BCLK	GPIO15
LRCK/WS	I2S_WS	GPIO02
DIN	I2S_DOUT	GPIO03
SD	NC
GAIN	NC
VIN	3V3 or 5V	3V3 or 5V
GND	GND	GND

Internal DAC~

ESP32 has two 8-bit DAC (digital to analog converter) channels, connected to GPIO25 (Channel 1) and GPIO26 (Channel 2).

Those channels can be driven via the I2S driver when using the “built-in DAC mode” enabled with USE_I2S_NO_DAC

Commands~

CMD DAC	action
I2SGain	`0..100` = sets the volume of the audio signal
I2SPlay	`/file.mp3` = plays a .mp3 audio file from the file system, in a separate task not blocking the system
I2SRtttl	`string` = play Ring Tones Text Transfer Language (RTTTL) ringtones (requires defined `USE_I2S_RTTTL`)
I2SSay	`text` = speaks the text you typed (only English language supported)
I2STime	tells current Tasmota time in English (requires defined `USE_I2S_SAY_TIME`)
I2SWr	`url` = starts playing an mp3 radio stream, no blocking (requires defined `USE_I2S_WEBRADIO`) no parameter = stops playing the stream

Audio Input~

This feature is not included in precompiled binaries

When compiling your build add the following to user_config_override.h: To use it you must compile your build. Add the following to user_config_override.h:

#ifndef USE_I2S_AUDIO
#define USE_I2S_AUDIO                    // Add support for I2S audio output (needed even if using only microphone)
#define USE_I2S_MIC                      // Add support for I2S microphone
//#define MIC_PDM                        // Set microphone as PDM (only on ESP32)
//#define MIC_CHANNELS 1                 // 2 = stereo (I2S_CHANNEL_FMT_RIGHT_LEFT), 1 = mono (I2S_CHANNEL_FMT_ONLY_RIGHT)
//#define MICSRATE 32000                 // Set sample rate
#define USE_SHINE                        // Use MP3 encoding (only on ESP32 with PSRAM)
//#define MP3_MIC_STREAM                 // Add support for streaming microphone via http (only on ESP32 with PSRAM)
  //#define MP3_STREAM_PORT 81           // Choose MP3 stream port (default = 81)
#endif

// USE_M5STACK_CORE2, USE_TTGO_WATCH and ESP32S3_BOX already include I2S_AUDIO

I2S Microphone~

I2S Microphone

For microphone input an I2S microphone must be connected.

I2S Microphone	ESP32	ESP8266 (fixed pins)
SCK	I2S_BCLK	GPIO13
WS	I2S_WS	GPIO14
SD	I2S_DIN	GPIO12
L/R	GND	GND
VDD	3.3V	3.3V
GND	GND	GND

If you're using only the microphone without a DAC you still need to set pin I2S_DOUT to an unused GPIO.

PDM Microphone~

Pulse density modulation (PDM) microphones are not an I2S or PWM microphone but still have a digital signal. They're used in ESP32-S3-BOX, Seeed Xiao Sense and others.

Compile Tasmota with MIC_PDM defined.

Microphone	ESP32
CLK	I2S_WS
DATA	I2S_DIN
L/R	GND
VDD	3.3V
GND	GND
NC	I2S_DOUT
NC	I2S_BCLK

When using PDM microphones the microphone CLK pin is configured as I2S_WS in Tasmota.

Commands~

ESP32 with PSRAM required!

CMD	Action
I2SMGain	`1..50` = sets the gain factor of the microphone
I2SRec	(requires defined `USE_SHINE`)`/file.mp3` = starts recording a .mp3 audio file to the file system, no blocking no parameter = stops recording `-?` = shows how many seconds already recorded
I2SStream	(requires defined `MP3_MIC_STREAM`) `1` = starts streaming .mp3 server at `http://<device_ip>:81/stream.mp3` `1` = stop the stream

I2S Audio Bridge~

Starts an UDP audio service to connect 2 ESP32 devices as an audio intercom (an example).

Needs audio output and microphone on 2 devices (no PSRAM needed)

#ifndef I2S_BRIDGE
#define USE_I2S_AUDIO                       // Add support for I2S audio output
#define USE_I2S_MIC                         // Add support for I2S microphone
#define I2S_BRIDGE                          // Add support for UDP PCM audio bridge
  //#define I2S_BRIDGE_PORT    6970         // Set bridge port (default = 6970)
#endif

CMD bridge	action
I2SBridge	`ip` = sets the IP of the slave device `0` = stop bridge `1` = start bridge in read mode `2` = start bridge in write mode `3` = start bridge in loopback mode `4` = set bridge to master `5` = set bridge to slave `6` = set microphone to swapped `7` = set microphone to not swapped `p<x>` = sets the push to talk button where `x` is the button's GPIO pin number

If a push to talk button is defined the bridge goes to write mode if the button is pushed and to read mode if the button is released