James, There is a section in the book titled "Programming and Customizing the 68HC11 Microcontroller", by Tom Foxx, which may be of some use to you. The circuit in question is a wind-vane. I reallize that a wind-vane is not really what you are looking for, but with some slight modification you could get it to tell the direction of your antenna rather than the direction of the blowing wind. The circuit uses no moving parts to tell the direction of the wind. I really cannot recall the specifics because I don't have the book in front of me right now, but I believe it uses Opamps to ampify the signal from thermistors. If this is the case, then all one would need to do is put a little maget on a piece of metal which hovered over a few Hall effect sensors, which are mounted at an absolute position, and voila! You have an Antenna position sensor. The nice thing about this project is that the code comes along with the book. If you like, contact me personally and I will send the relevant code to you. Just an Idea... LF jameshickox <> wrote: Hello all, My name is James and I am an amateur radio operator interested in satellite communication. Reference to the December, 1998 edition of QST magazine where the VE5FP rotator controller is found. Has anyone written a program to allow the controller to get real time pointing instructions from an orbital prediction program, and have they used the a/d converter on the ad11c75 to sence where antennas are pointed? --------------------------------- Yahoo! Groups Links To --------------------------------- |