<http://www.theregister.co.uk/2018/01/22/rob_joyce_hacking/>: Joyce uses a couple of Raspberry Pis to control the light show and a slightly dodgy FM transmitter to broadcast the soundtrack to visiting folks. The transmitter, bought as a kit from New Zealand, has the capability to broadcast illegally on FM frequencies, so is sold without the power supply attached to get around regulations, but Joyce said he keeps it low power and within FCC regulations because "I'm very legal."