It used to be that upgrading a car stereo was fairly simple. There were only a few mechanical sizes and you could find kits to connect power, antennas, and speakers. Now, though, the car stereo has interfaces to steering wheel controls, speed sensors, rear-view cameras, and more. [RND_ASH] was tired of his 14-year-old system so he took an Android head unit, a tablet, and an Arduino, and made everything work as it was supposed to.
The key is to interface with the vehicle’s CAN bus which is a sort of local area network for the vehicle. Instead of having lots of wires running everywhere, today’s cars are more likely to have less wiring all shared with many devices.
[RND_ASH] has several videos describing the whole project and we expect there will be some more upcoming. You can see part one, below.
The project also reverse engineers how to display on the tiny screen in the dashboard. The code for the CAN bus interface is on GitHub. There’s also a written narrative on what he learned about the Mercedes interface in a different repository.