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Sine Wave Generator with ReSpeaker Lite

This project demonstrates how to generate a sine wave and play it using the I2S interface on the reSpeaker Lite board. The reSpeaker Lite is an audio board with an integrated XIAO ESP32S3 microcontroller, featuring a dual-channel microphone and speaker.

Functionality​

  • Generates a sine wave with a specified frequency
  • Plays the generated sine wave through the I2S interface
  • Utilizes the AudioTools framework for audio processing and streaming
  • Easy-to-use AudioLogger for debugging and monitoring

Code​

#include "AudioTools.h"

AudioInfo info(16000, 2, 32);                              // Sample Rate, Number of channels: 2=stereo, 1=mono, Number of bits per sample (int16_t = 16 bits)
SineWaveGenerator<int16_t> sineWave(32000);                // subclass of SoundGenerator with max amplitude of 32000
GeneratedSoundStream<int16_t> sound(sineWave);             // Stream generated from sine wave
I2SStream out; 
StreamCopy copier(out, sound);                             // copies sound into i2s

// Arduino Setup
void setup(void) {  
  // Open Serial 
  Serial.begin(115200);
  AudioLogger::instance().begin(Serial, AudioLogger::Info);

  // start I2S
  Serial.println("starting I2S...");
  auto config = out.defaultConfig(TX_MODE);
  config.copyFrom(info); 
  out.begin(config);

  // Setup sine wave
  sineWave.begin(info, N_B4);
  Serial.println("started...");
}

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

Configuration​

info: Defines the audio configuration, including the sample rate, number of channels (2 for stereo, 1 for mono), and the number of bits per sample (16 bits).

sineWave: Creates an instance of the SineWaveGenerator class with a maximum amplitude of 32000.

sound: Creates a GeneratedSoundStream object using the sineWave generator.

out: Creates an instance of the I2SStream class for audio output.

copier: Creates a StreamCopy object to copy the generated sound to the I2S output.

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