i2s.onReceive with is2.read only reading 1 byte

[DigitalMakerCIC]

I'm trying to use the is2.onReceive function with is2.read to read the whole buffer into an array. But am only reading one byte.
Is there a method for determining the optimum setBuffers sizes?

// Audio buffer settings for 24-bit audio
const size_t BUFFER_SIZE = 256;   // Samples per buffer
int32_t audioBuffer[BUFFER_SIZE]; // 32-bit buffer for 24-bit audio data

in setup
i2s.setBuffers(2,256,0);

  // Set the callback for when audio data is received
  i2s.onReceive(onI2SReceive);

// I2S receive callback - called automatically when audio data is available
void onI2SReceive() {
  // Read available audio samples (24-bit data in 32-bit containers)
  size_t bytesRead = i2s.read(audioBuffer, sizeof(audioBuffer));
  Serial.println(bytesRead);
 
}

[earlephilhower]

You're being bitten by the C++ compiler type inference rules. Use a case to u8_t* to get the block read:

size_t bytesRead = i2s.read((uint8_t *)audioBuffer, sizeof(audioBuffer));

Right now your code is calling the non-blocking single read API.

There was also a bug in returned size (off-by-4x) fixed in #3086