My homebrew doorbell circuit. ATMEGA8 with 2 L293D push/pull driver chips running each of 12 solenoid-driven christmas bells. Songs are stored in EEPROM, and selected randomly when the doorbell is rung.
Okay, that’s a pretty geeky application, and deserves the appropriate applause. It also points out a market for geeky families that is woefully underserved: custom ringtones for your door bell. There are a few devices out there in the $50-$100 dollar range (and more expensive), but none of them seem to really get it. How hard would it be for one of us GeekDads to develop a door-notifier that synced wirelessly with our home computer (perhaps even with an iTunes playlist), so that adding and removing songs was as simple as feeding an iPod? Doesn’t seems like it would be that hard, combining the guts of a cheap 32mb mp3 player with a wireless chip (use 802.11b to save cost), and a decent speaker. Extra points for cramming all the guts into an Altoids tin! Who is up for the challenge?