I have started experimenting with the Audio library. My experiment is to connect a very low frequency sine wave to the DAC0 and "listen" to it on a breadboard with an LED (ie: the LED blinks in time to the oscillations).

Here is the code:

#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>

// GUItool: begin automatically generated code
AudioSynthWaveformSine   sine1;          //xy=236,269
AudioOutputAnalog        dac1;           //xy=406,263
AudioConnection          patchCord1(sine1, dac1);
// GUItool: end automatically generated code

void setup() {
  sine1.frequency(5); // -- this does nothing

void loop() {
I have an LED wired between DAC0 (pin A21 on the supplied pin sheet) and Vin.

The LED blinks at a rate about 1HZ or slightly faster. I then added the line to set it to 5HZ, but this changes nothing.

Strangely, if I comment out the AudioSynthWaveformSine and AudioConnection declarations, leaving only the dac1, it keeps blinking. It seems like there's some kind of default signal running?

I plan to do some audio processing and wire up input / output audio jacks, but don't have the parts yet, so figured I'd start getting familiar with the Audio library. Also, I don't want to use the audio-shield board.