To build this example you are going to need the following items:
- Arduino Uno
- Traffic Light module
- USB A cable (the sort you use on a printer)
- Arduino IDE (which can be dowloaded for free from www.arduino.cc)
Instead of the traffic light module you you can use three LEDs but you must use resistors in series with them as well the need for a breadboard. I will show you the circuit diagram for this below.