This instructable walks you through programming and using the Boston Android Xmega evaluation board to work as a simple arbitrary waveform generator taking advantage of the integrated 12bit DAC and high speed DMA controller. I have provided precompiled firmware as well as source code which can be loaded onto the device and configured via a USB port on your PC or laptop.
You will need a computer (mac, pc, linux all supported) with an available USB port, free driver for the USB-Serial adapter, a Boston Android Xmega EVAL-USB-64 development board
($31.99) and an open source AVR chip programming utility called AVRDUDE
Once set up, you can generate sine, ramp, triangle, square or any waveform you define from 5 to 20KHz with amplitude of up to 3.3Vp-p. It is possible to generate faster waveforms with the arbitrary waveform feature (up to 500KHz).