Giles Booth wanted to get started with physical computing using the Pi. Luckily, Ben Nuttall had just announced GPIO Zero, the new GPIO library from the Foundation. So, Giles got hold of some simple electronic components and wrote a traffic light project using Zero. Read about his efforts here. Shameless plug: If you wanted to do something similar, the easiest way to get hold of the necessary electronic components is to buy the first CamJam EduKit. You get everything you need for £5 + postage.