Putting Bluetooth into a flea market toy car

On the flea market here in Ghent a few weeks ago, I bought myself a toy car with a wired remote control. Feeling destructive, I immediately removed the hood of the car, opened up the remote control and measured how the car could be controlled. It turns out there are four wires from the remote to the car. Two of them control the forward / backward motion by setting 5V or -5V across them. The two other wires control the left / right motion of the front wheels, again by setting 5V across them.

Next I soldered header pins to the wires of the car so I can control them through the L293D driver chip of my Dwengo board. Next I added the Bluesmirf module (as explained in a previous post) and taped everything together using Duct tape.

After some programming and some tweaking (putting the battery pack above the steering wheels so they have more grip) I got my car driving across the appartment

edit: latest version of code is now available via https://github.com/kr3l/rommelrubot