This is a pet project I've been playing around with in my head for sometime now and I've finally taken the leap and started it.
My aim is to convert a cheap RC car into a robot chassis controlled by Arduino so I can easily experiment with robotics.
My original plan was to fake the the reciever's signal and run the motors through the provided PCB board in the car but it was so tightly packed and crappily wired I abandoned that idea, cutting wires and starting from scrtach.
I bought two RC cars together coming to about 15 dollars. I've only opened one so far- I've taken off the plastic body and opened up the body. I cut out the PCB and am attempting to figure out how to run the car's motors with Arduino. Plugging the motor directly into 5 volts causes the USB port to go on and off on Windows XP (I'm assuming it's tripping the USB protection which means I'm running too much current through arduino). On 3 volts it does this on the initial get-go and then when i stop the motor by hand, which once again makes sense.
I switched over to a Texas Instruments SN754410NE H bridge chip and thanks to this tutorial: http://itp.nyu.edu/physcomp/Labs/DCMotorControl I was able to get everything wired up. I decided to call it a night when the included battery pack's wire broke cause of the car's crappy soldering.
If I can get motors to run decently this weekend I think I can have proximity sensors installed next weekend with some basic behavior algorithms. So far the project is a success. I'll post more later.