What Is This Thing Anyway?
This is a rotor controller that is intended to make working Low Earth Orbit (LEO) satellites a bit easier. It provides automatic antenna tracking of the LEO satellite from horizon to horizon. It assumes you have stacked an elevation rotor on top of an azimuth rotor, both U100s) and connected them to the controller describer here.
The controller requires a serial RS232 line to a computer running NOVA and set-up to use the Novacomm1 rotor interface protocol. NOVA is a popular satellite tracking program.
I recently added the MacDoppler interface protocol. However, it is still experimental and has not had much testing as of 3-3-2014.
This rotor controller is different than others I have seen in that it calibrates itself to the rotors. That is, it counts the pulses coming from each rotor (calibrate mode) as they are rotated through 360 degrees (rotor stop to rotor stop) and calculates how many degrees there are between pulses. So if you have modified your U100 by adding more lobes on the internal gear that hits the rotor contracts, to get 5 degree accuracy instead of the default 10 degrees, that will work fine with this controller.
By monitoring the rotor's pulsing contacts and knowing which direction the rotor is turning, the controller can know the actual bearing of the rotors when the pulse is detected. In addition, it times between rotor pulses (when the motor is running) and updates the bearing to achieve a higher degree of accuracy. The controller writes the rotor data to non volatile memory every time the rotors stop moving so it remembers where the antenna array is if it loses power or is simply turned off.