Analog Audio Output on an STM32H7

In my last post, I have introduced you to the powerful STM32H743VIT6 microcontroller.

Now it is time to test some audio output.

I don’t have any special implementation for the output of analog audio for the STM32H7, but I decided to try to use my generic implementation that is part of by my AudioTools library which is based on the Arduino analogWrite() in combination with a timer.

I adapted the standard example to use stereo and defined the analog pins PA4 and PA5 which are connected to the internal DAC:

#include "AudioTools.h"

AudioInfo info(44100, 2, 16);
SineWaveGenerator<int16_t> sineWave(32000);                
GeneratedSoundStream<int16_t> sound(sineWave);             
AnalogAudioStream out; 
StreamCopy copier(out, sound);                             
int pins[] = {PA4, PA5}

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

  // start the analog output
  auto config = out.defaultConfig(TX_MODE);
  config.setPins(pins);
  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();
}

I was testing the result with an oscilloscope and I was getting the following:

This looks very promising indeed!