Controlling an RC Car Like a Racing Simulator

Back in 2020, Nintendo released a very interesting product called Mario Kart Live: Home Circuit. It was, in essence, a Mario Kart game played in the real world with RC cars and miniature obstacles, plus virtual augmented reality objects thrown into the mix. It didn’t end up being very successful and sales were discontinued, but the idea was both novel and intriguing. We aren’t sure he knew about that or not, but bitsbits implemented a similar concept when he set up his racing simulator to work with an RC car.

If the beautiful third-generation (FD) Mazda RX-7 project car garage in his garage is any indication, then bitsbits is a serious motoring enthusiast. But that car appears to be stationary at the moment (probably bad apex seals, if we had to take a guess) and so bitsbits has to get his racing fix through sims. He has a pretty nice rig, with all the gear necessary to take an optimal line through the corkscrew at Laguna Seca. And because he was interested in that sort of the thing, the almighty algorithm showed him something interesting: VBR Playground.

VBR Playground is a “teleoperated racing system” and is like a much more expensive and sophisticated version of Mario Kart Live: Home Circuit. After seeing that, bitsbits realized he could build something similar using his racing sim rig and an RC car.

To achieve that, bitsbits needed to find a way to link his racing sim rig to the RC car. There are many, many ways one could achieve that and bitsbits initially tried to monitor the racing sim hardware (the steering wheel and pedals) directly using potentiometers. But that proved to be a poor choice, as the signals were difficult to work with and the performance was poor.

Fortunately, bitsbits realized he was reinventing the wheel, because the manufacturers of the racing sim gear already put all the work into tuning the hardware. With that in mind, his new solution was to connect that to a PC as intended and use a Python script to read the inputs. The script then sends the relevant data (pedal positions and steering angle) to a connected Arduino through serial. That then goes through a standard RC transmitter and receiver to an Arduino Pro Micro on the RC car, which controls the motors.

An FPV camera system gives bitsbits a view from the “driver’s seat” of the RC car in the racing sim, so driving the RC car in real life is just like driving a virtual car in a racing sim. It is the next-best thing to driving that RX-7 out on a track.