Adding what every Traffic Light needs. Sound!

After a bit of a discussion with a friend I have also decided to combine the existing traffic light with a humorous and not at all annoying audible notification of tickets being closed. I have a speaker which runs on a 3V cell, which should work very well with the Raspberry Pi's 3V out pins.

A separate switch also means that it can be turned off independently if it proves to be too annoying. You can see in the picture the almost complete setup. The Pi is a B+ with the Raspberry Pi USB Wifi adapter.