I'm trying to send signals over a wire pair to a hobby R/C receiver.
The protocol it uses is simple. It consists of a series of frames.
Each frame consists of a series of pulses at 5V (that's what the
parallel port puts out), delimited by short periods of 0V. The
duration of each pulse determines the position of the servo. The
current that actually drives the servo motors will come from a
seperate, dedicated 5V power supply. This parallel-port current serves
only as a 'where to point the servo wheel' message to the
microcontroller in the receiver and can be very low amperage. If
necessary, I could amplify it with a transistor.
So does anyone know how to turn a pin in the parallel port on and off?