I am trying to connect my mini-z car to an arduino mega board so I can read and change several parameters. (a mini-z is a small RC car running on 4 AAA batteries)
The cable to do this with a pc is like this: http://mini-zracer.com/forums/showthread.php?p=343711
The mini-z car has a vcc 5V; GND and one signal connection. The above circuit converts the rs232 voltage into 5V for the mini-z
The problem is there is only one signal carrier for both transmission and receiving data. I know to little of electronics to convert the circuit.
I have been able to do make a program on the PC, so the protocol etc is no problem, its connecting the damn thing to the arduino.