First commercial electronics project I've had. Basically the company had this problem, that emplyees knew when to have a break but somehow always forgat when it finishes. Well, the company asked me if I can make a system which controls the bells in their company.

What I did is, I made a PCB with atmega8 micro-controller which controlls the relays attached to it. Oh yeah the bells are driven with 220V. And then I made a windows application which connects to atmega8 through rs232 and sends signal when and which bell to ring. In the software the user can control the week day, time and which bell to ring. Simple yet effective solution for making sure employees know when to work or relax. Nex step would be to make it work without computer, all the time tracking would be done inside micro.