The ‘remote switch’ which Danielle used in the Royal Institution lecture theatre to control a single mains powered bulb used a servo motor (of the type found in model cars or aircraft) to toggle a standard in-line mechanical switch. This provided a safe method for using low-cost embedded computing boards, such as the Raspberry Pi or Arduino, to switch a 240V AC powered light bulb.
The light bulbs used in the Tetris-like game (on the Shell Building) incorporate a wireless radio interface, so that their individual colour and intensity can be remotely programmed.
The light switch which turned the desk lamp on and off was built using a servo motor, an Arduino micro controller and an Ethernet shield for the Arduino. The Arduino was programmed to turn the servo arm enough to flick the switch on the lamp on when it read that the status of the switch on a webpage had been set to “on”. The Ethernet shield allows the Arduino to connect to the internet to check the state of the switch on the webpage.