I2S to SD card

[tomv2]

Hi, has anyone managed to record audio to a SD card from an I2S input? If there's an example that would be great. Currently I am using the I2S to I2S example where essentially the mic is in monitor mode. I now hope to save that data as a .wav. I see there was some discussed previously but unable to get anything working myself.

I am using an ESP32-S3-WROOM-1

Here is the example that is working:
`#include "AudioTools.h"

uint16_t sample_rate=44100;
uint16_t channels = 2;
I2SStream in;
StreamCopy copier(in, in); // copies sound into i2s

// Arduino Setup
void setup(void) {
// Open Serial

Serial.begin(115200);
// change to Warning to improve the quality
AudioLogger::instance().begin(Serial, AudioLogger::Error);

// start I2S in
auto config = in.defaultConfig(RXTX_MODE);
config.sample_rate = sample_rate;
config.bits_per_sample = 16;
config.i2s_format = I2S_STD_FORMAT;
config.is_master = true;
config.port_no = 0;
config.pin_ws = 18;
config.pin_bck = 5;
config.pin_data = 19;
config.pin_data_rx = 17;
config.pin_mck = 0;
config.use_apll = true;
in.begin(config);

Serial.println("I2S started...");
}

// Arduino loop - copy sound to out
void loop() {
copier.copy();
}`

[pschatzmann]

I suggest that you decide first on what SD card API you want to use and learn how to use files: You can use SD, SDMMC or SDFAT.
A file is just a stream, so it can be used as copy destination by using StreamCopy. At the end don't forget to close the file - otherwise you will not have any data!

Only after you know that your files are working move to the next step!

I suggest that you have a look at the following example which creates and then plays a file using the SD library: https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/examples-audiokit/streams-audiokit-sd-audiokit/streams-audiokit-sd-audiokit.ino. It uses the AudioKitStream as input and output, so you can just replace it with an I2SStream ...

How to create a wav file is explained here: https://github.com/pschatzmann/arduino-audio-tools/wiki/Encoding-and-Decoding-of-Audio. You just wrap the file in a EncodedAudioStream with an encoder!