Connecting Arduino to Mini-z

Hi

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: [DIY]MINI-Z ASF/ADBAND/dNaNo I.C.S Cable - Mini-ZRacer.com Forums

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.

I've had a look around and I think (only a guess) that its a one-wire serial link - ie RX and TX share the same signal wire. Try connecting a 1k resistor from TX to the signal wire, the signal wire to RX.

Then you ought to be able to send serial data via the resistor while the other end is in input mode, but not damage anything if it sends at the same time. Stuff you send will be echoed back of course.

You can start experimenting with the chip taken out of the Arduino - this time connect the RX pin via a 1k resistor to the signal line and the TX pin directly to the signal line (so the USB-serial chip can talk direct). In fact having a 1k resistor on both RX and TX pins allows both the Arduino and the USB-serial chip to talk down the line...

Quite what to send (and what baud rate)? - try reverse-engineering the Linux version of the ICS software? If there's no documentation that is.

Very simple yet very effective solution

Its working now. I send c5 in hex and i get 18bytes of data back.

Thank you