Features:
* 8 bit parallel waveform output (for DAC, or R/2R ladder)
* one PWM-modulated waveform output (easy to buffer and filter)
* one delta-sigma modulated waveform output (even easier to buffer and filter)
* Simple command interface (serial data at 115200 baud)
  F100\n   - sets frequency to 100 Hz (note: fractional frequencies currently not selectable)
  Fxxxxx\n - sets frequency to xxxxx Hz
  W[256 characters] - uploads a new waveform to a temporary buffer, which is put
                      in waveform RAM when the last byte has been transfered.
                      (note: 256 bytes directly following W is the new waveform)
  M0\n     - Triangle wave
  M1\n     - Square Wave
  M2\n     - Use waveform ram 
  
  ?        - Query some registers (response as serial data at 115200 baud)

Copyright (c) 2009 Simon Gustafsson (www.simong.se)
