In the Back to the Future films, the iconic DeLorean time machine had to reach 88mph in order to jump forward or backward in time. Even in 1985, it wasn’t very hard for a family sedan to reach 88mph, but that’s not the point. To show viewers the car’s current speed and increase tension, the prop designers brilliantly included a large digital speedometer readout on the remote that Doc holds. W. Jason Altice used Arduino boards to replicate that functionality on a rented DeLorean.

Altice rented the replica Back to the Future DeLorean from a company that caters to fans. That company wouldn’t let Altice modify the car, of course, so he wasn’t able to create a remote that actually controlled steering or throttle. But he was able to track the car’s speed and display that on a vintage RC-style transmitter without modifying the rental. He achieved that using two Arduino Uno boards that communicate with each other through REYAX RYLR998 LoRa transceiver modules.

The first Arduino sits in a simple plastic project box in the DeLorean. It uses an Adafruit Ultimate GPS Logger to monitor the car’s location and then calculates the speed with that data. It shows the speed value on a three-digit seven-segment display on the project box and also transmits the value to the second Arduino attached to the RC remote. That Arduino has another seven-segment display speedometer readout. With some glued-on wires and switches, the RC remote looks a lot like the prop from the movie and let Altice cosplay as Doc Brown with accuracy.