Things I've Built
AVR based audio playing doorbell
Plays 8-bit audio samples stored in serial EEPROM at 22.05kHz using serial DAC and LM386 audio amplifier. See http://www.nomad.ee/micros/doorbell/
AD9850 based RF generator with AM and FM modulation and frequency sweep
Cheap to make RF generator for working on old radio equipment. See http://www.nomad.ee/micros/rfgenerator/
Pet feeder
Battery powered pet feeder with 3D printed auger mechanism and minimalistic UI using 7-segment LED displays. See http://www.nomad.ee/micros/pet_feeder/
Z-Two, a CP/M machine with Z80 emulated on ATMega
4 chip machine, uses SD card for storage, has integrated VGA and PS/2 keyboard interface. Emulates Z80 instructions at about 110KIPS, and runs CP/M 2.2. See http://www.nomad.ee/micros/z-two/
Lutetium