Control RC-Car with PC

For controlling a Car with a pc I build a simple little hardware with an Atmel Mega 8 microcontroller, a Max232 (Serial Port Voltage converter) and some resistors and capacitors.

The microcontroller receives simple controlmessages from the pc, like Servonumber (1-6) Servoposition (1-255) and a 0 as end of command.

The Timer1 of the microprocessor generates the ppm Signal for the radio which has an input conector for a pupil signal. The program is written in C and is rather simple. An array of 16x2 values defines the preload values for the timer1.

lValue[0][0] = 8199
lValue[0][1] = 0
lValue[1][0] = 5000
lValue[1][1] = 1
.
and so on.

The first field contains the timer1 preload, the second one if the output is high or low. So, it needs only a very little computation time, everything is controlled by interrupts, even the serial port.

As radio I used the DX-6 a 2,4 Ghz transmitter. I removed the pushbutton for the trainer mode and replaced it with a normal switch so that I have my hands free.