Anthony Mattox wrote some very excellent software for use with the ProtoDAC project I posted up a while back. Built using Processing, the software turns the simple digital-to-analog converter into a synth/sequencer using waveforms drawn by the user. He adds an amplifier and simple filter on the hardware end of things as well –
On the electronics side, my setup is quite similar to my reference, with the addition of a small amplifier using an LM386 op amp chip and a couple resistors and capacitors for some basic filtering. On the code side Iâ€™ve created a much more substantial instrument. Using Processing I built an interface to create a 32 sample waveform and a melody. The data is sent live to the Arduino which places the data into itâ€™s waveform array and then using a timer writes each value sequentially to the DAC to create the sound.