Now that I can trigger buttons with Arduino (a post or two back), I bought a cheapo RC car from Walmart and almost immediately tore it apart :)
The Victim: New Bright RC Corvette
It contains a NEW BRIGHT T288-2 0726 chip, which some say is just a re-branded TX2c(very common IC for cheap RC), and i would have to agree as the pin out is almost identical and functions the same. The IC encodes the button status(on/off) to a radio signal that the receiver can decode and act accordingly. The buttons function the same as the older remote i was tinkering with in my previous post, so that makes it easier to interface with a Arduino(just a diode to a digital pin). They are +3v when open, 0v when closed. I found it annoying trying to solder a wire directly on to the button pin, but for some reason their were little solder pads on each trace for each button, so i just connected the wires there. This IC, i believe, also has a turbo function, which is normally used for extra features on the car(lights, sound etc) that are non existent on this cheap model. I think ill still solder a button to the IC pin and make a little hole in the remote case to mount it and to utilize this extra pin. Maybe add some headlights to the car?
In this second picture you can see the wires to a header accessible to the outside for the Arduino and the new TURBO button for the car headlights. I put the diodes for triggering the button inside the case for easier interface with the Arduino. I brought out VCC to the header too so that i can power the remote from the Arduino, if necessary. Also, i cut a little hole in the case for mounting the TURBO button.
EDIT: I have found that the turbo button isnt just an extra "channel" it messes with the movement of the car too. With turbo on, the car goes forward and left when i press the left button, same for right too. Forward/Back don't work anymore.
It contains a NEW BRIGHT R288-2 0802 chip(again, probably a RX2c clone). not much to explain here... The IC receives the signals, decodes them, then turns on/off the mosfets(L,R,B,F) depending on what data it has received. The wheels use a normal DC motor for turning, not a servo. 5AA batteries at 1.5v, so about 7.5v total, but the IC runs at 3v. Now that i found the TURBO pin on the remote and added a button for it, i can put in another NPN transistor on the car and put some headlights in :)
TX2c_RX2c.pdf is a datasheet for the TX2c and RX2c; the only difference i can find between the NEW BRIGHT IC and the TX/RX2c is that the Left/Right pins are switched, and the Forward/Back pins are switched.