AVR DDS signal generator

AVR-only (with no specialized DDS chip and no DAC chip) DDS generator from scienceprog.com seems to be valuable addition to hobbyist workshop. Its output frequency range is limited to 65 kHz for DDS signals (sine, square, saw, rev saw, triangle, ECG, noise) but that seems sufficient for many needs and it allows to use cheap operational amplifier and R-2R digital to analog converter. Additional HS (high speed) digital output would be useful as a spare external clock source for microcontroller projects or restoring misconfigured AVR fusebits.

New project version with improved analog part and some additions to firmware is planned to be released this summer.