Norbert Okec, from Uganda, designed and built a solar-powered traffic light controller system from recycled materials. A controller board monitors the whole solar system and turns on/off LED traffic lights. This LED based public lighting system can also be connected to any power grid, thanks to the controller board.
Norbert Okec asserts that he has succeeded in simplifying a rather complex system (traffic lights). Thanks to its simplicity, the system can be easily designed and maintained. It is also open source, and the inventor, in 2010, affirmed that he was working on a free eBook (with circuit’s diagram of the controller board, among others) that would explain how the system can be manufactured.