I wanted to make something for my partner for Valentine's Day 2014. Browsing the local Maplin shop, I came across a Velleman kit in the shape of a heart with ~30 LEDs. In its standard frm, the kit just flashes all the LEDs on and off at a few Hz - it's just a two transistor astable circuit - nothing too exciting. I bought it and started thinking about how to upgrade it once I had it back in the workshop.
First off, I ditched the 3mm LEDs and plumped for some 5mm ultra high brighness ones, unfortunately I ordered 8mm by mistake so some filing and brute force was needed to get them to fit the PCB. I'd wanted to try charlieplexing for some time, so this seemed like a good opotunity. I had some PIC16F883 devices in SMT form in the spares bin , these are small enough to fit on the back of the heart PCB and will run with no extra parts - that made selection of controller easy - use those.