For valentine’s day in 2009 I designed a heart board for my girlfriend. It has 18 LED’s mounted around the outside, its controlled from a cheap PIC16 with a simple external RC oscillator. Its powered by a coin cell mounted on the rear, although there is also a spot for a separate power connection. It can be run at 3V off the battery or 5V externally but the timing for the RC oscillator will be faster, and the LED’s will be much brighter. The LED pattern is controlled by the switch on the front of the circuit board and its an awesome red circuit-board.
You can get the Eagle-Files-LED_Heart_v08.
As a side note you need to install the HI-TECH C compiler and to compile it with the lite version you need to remove the inversefollow() function, calls to it from main, and prototype. Or you can just get the updated hex file to load on to the pic here (you have to change the extension from “.txt” to “.hex”.
The original Assembly manual is posted here. A better one will be uploaded as soon i have time.