Here's a one day project done while home sick from work. I ordered a pair of ATtiny13v's the other day and they've been sitting around on my work bench. It struck me while I was making my kids breakfast what I could use them for: PumpkinLight!
I'm a few months into a new electronics hobby (read as: obsession) and just now getting to microcontrollers. I played with PIC stuff a little and just recently built my first AVR device. The Pumpkinlight is my first foray into AVR assembly and my first ground-up project that looks to have a practical use (lighting up my daughters' Jack o' Lanterns this Halloween.
I posted the project on AVRFreaks:
Pumpkin Light
Pumpkin Light uses two high-output 5mm white LEDs, a nine volt battery, a ATtiny13v and a handful of parts to create a flasher that you can put inside a pumpkin or other light-up decoration.
Included in the archive is the asm source which implements three distinct flashing patterns. The ATtiny13v's internal timer is used to interrupt each pattern and advance to the next. The patterns are Shimmer, Strobe and Alternate. Additional flashing patterns can be added simply. Very little of the ATtiny13v's program space is used up by this program.
Here's a direct link to the archive with the schematic, BOM, pictures of the parts and the assembled unit, source code, AVR Studio 4 project, and so on.