Pi-Rotate

Antenna Rotator for Raspberry Pi

Prerequisites - Hardware

• 1 x Adafruit Motor DC & Stepper Motor HAT https://www.adafruit.com/product/2348
• 2 x Stepper Motors 12Vdc https://www.amazon.com/gp/product/B00PNEQCLO
• 1 x Raspberry Pi (3B or later)
• 1 x 12Vdc Power supply for motors
• 1 x 5Vdc Power supply for Pi

Prerequisites - Software

• Raspbian
• Python3
• Adafruit CircuitPython MotorKit https://github.com/adafruit/Adafruit_CircuitPython_MotorKit
• Hamlib https://github.com/Hamlib/Hamlib/wiki

Optional - Software

• GPredict http://gpredict.oz9aec.net/ (or any other program compatible with hamlib/rotctld)

Setup

• Install the Pi HAT on the Pi https://learn.adafruit.com/adafruit-dc-and-stepper-motor-hat-for-raspberry-pi/assembly
• Install Raspbian and the other prerequisites
• Download files from github Pi-Rotate and stepper directories
• Test motor operation with program stepper.py

Operation

• In a terminal, start program Pi-Rotate.py make note of the pseudo terminal name, probably: /dev/pts/0
• In another terminal, start program rotctld: rotctld -m 202 -r /dev/pts/0 (the last argument must match terminal name above)
• In another terminal, start program rotctl: rotctl -m 2
  • use the P az el command to point the antenna North and level
  • use the R x command to reset the az & el
  • quit
• start gpredict
  • verify time & direction of upcoming pass
  • open Antenna Control window; choose satellite; Tolerance 0.2 deg; Engage; Track