I picked up several RC vehicles at the 2nd hand store a week or so ago. I wrote up the results of the first experiment previously. This time I picked a vehicle that had differential drive and would thus be ideal for a robotic platform. Differential drive gives the ability to turn within the vehicles own footprint which is handy for a robotic platform. Instead of using my own motor drivers I decided to use the ones built into the RC vehicle. This vehicle did not come with a remote control, so I couldn’t do the same hack I did by just hacking into the remote. I disassembled the vehicle and hooked up power and ground. I then started probing the different pins of the RC chip with a five volt signal through a 220 Ohm resistor. 
Sure enough there were two pins that controlled each motor. Now interfacing was dead simple. De-solder the RC chip. 
Solder 4 wires to the holes identified earlier. (Sorry about the quality of the picture. You can see where the chip was removed. The wires are potted in hotglue to provide stress relief. Run those wires to the PicAXE outputs with 4.7 K resistors to limit the current. Program the PicAXE, add batteries and wallah instant robotic platform! I did add a piece of expanded PVC as a top platform.
