K9 was originally a companion of Tom Baker’s Fourth Doctor, and the robotic dog made his first appearance in 1977’s The Invisible Enemy episode of Doctor Who. Throughout the show’s long run, K9 has provided computing knowledge, laser weaponry, and occasional sassy commentary. When student Gary Taylor came across a K9 prop used on the show, he decided it would be the perfect project for his computer science dissertation.
The K9 prop was purchased by Abertay University from the BBC in 2011, alongside several other Doctor Who props. When Taylor came across it in the university’s lab, it was water damaged from a leak in the building. As a Doctor Who fan, he decided it was worth resurrecting and set out to rebuild it using modern technology. Most of the original K9 props were simple radio-controlled machines that were brought to life with special effects magic, and not really true robots. But, Taylor wanted his to have some of the capabilities of the K9 character, so he turned to a Raspberry Pi.
Packed inside of K9’s body is a Raspberrry Pi 3 and an Arduino Mega. The Arduino receives input from ultrasound sensors, and provides motor control for K9 to move about. The data from the ultrasound sensors is fed to a Raspberry Pi, which in turn manages an SQLite database and connects to an Android app via Bluetooth. The app uses that hardware to create physical maps of K9’s environment, allowing the robot to roam autonomously. He may not be able to fire a laser, but he can certainly find his way to the TARDIS.