What does the AX2550 want to hear?

Say I'm creating a signal through a microcontroller for the AX2550. Theoretically, I could simulate a serial port signal or a servo signal or whatever.
So which is the easiest and how can I find all the technical specifics of it?



The thing is is that I have the AX2550, a USB joystick, and two motors, and two optical encoders, and a PC, and I want a wired (not R/C) closed-loop two axis system.
I'd like to get the PC out of the loop, replace it with a microcontroller (perhaps the MAKE microcontroller).
I've given up on using the USB part of the joystick; I'm going to rip it apart and just use the pots and switches for an analog signal.

So what does the AX2550 want to hear?


thanks

Generating RS232 commands is the easiest and produces the best results.

Next best is to generate RC pulses. If your MCU has two timers then you can easily create the 1.5ms pulses.