A traffich light, made with LEDs (red, yellow and green). It can communicate to serial port wich led is on, and it can be switched on and off by serial port. When you switch it off, the yellow led starts blinking.

You will need:

- Red led;

- Yellow led;

- Green led;

- 3 resistence 220 ohm;

- 1 resistence 10K ohm;

- 1 button.