AE EP#23 AVR DDS Function Generator

While exploring the different methods of generating some waveform I stumbeled on an old project of mine that has been shelved for almost a year because it would not work no matter what I tried. So I got out, redesigned the pcb, soldered new components and wasted 4 hours tracking down some trace issues. But in the end I had a working DDS function generator based on this simple but effective design: