[alistairsam]

Hi,

I've built a picaxe mcu based stepper motor controller for a home built equatorial fork, and am adding ST4 autoguiding to it.

I traced the ST4 pins on a qhy5 guide camera and interfaced it to a picaxe microcontroller and LED. I chose "mount on camera" in PHD and can now get the ST4 pulses to speed up or slow down RA.

What I wanted to know is if someone can explain the normal behaviour of a Hand controller, that is while tracking is on and the motor is tracking at sidereal rate, what happens when you press the east or west button, does the speed of the motor increase or decrease by 50% or is the amount different?

I can vary the amount of correction easily enough in the code.
I just don't want the speed corrections to be too small or too large.

I'm not sure if the manual for any mount explains this.