Make your own free website on


Page One Title

 Automatic Satellite Tracking Rotors Controller

     Welcome to the dual-axis rotors control interface page.  I have developed this automatic antenna pointing inteface specifically for amateur radio satellite tracking operations.  This rotor control interface is quite simple to build.  The circuit consists only one PIC16F877 microcontroller IC and a few transistor drivers.  Please take a moment and look around.  You might find something helpful !
     Satellite tracking is done most commonly on a computer with a satellite tracking software.  The FODTrack ( by XQ2FOD ) software, which I am experimenting with this control interface, is available for download at  It uses serial ( COM ) port ( baud 1200 ) on your PC to drive the external azimuth and elevation rotors to position the antenna via the interface described here.
     Assembler software to program the PIC16F877 is available for download at and the P16PRO printer port PIC eeprom programming software is available for download at .
     PIC16F877 microcontroller uart serial port baud rate is 1200 and the crystal clock frequency is 10 MHz.  The two-axis ( azimuth and elevation ) rotor drive output pins are RB1, RB2, RB4 and RB5.  Rotors position analog input pins are AN0/RA0 and AN1/RA1.

Controller circuit board


Controller source and hex files download

Source file

Hex file