Autonomous Satellite Tracker

This page refers to my Autonomous Satellite Tracker article in the March/April 2016 QEX. All updates will be posted here.

Supporting Material:



  • Version 2016061704 fixes a problem that prevented entering values in Firefox and Android.
  • Version 2016073023 fixes a problem that prevented downloading elements from AMSAT or
    Celestrak in Firefox and Android.
  • Version 2016082822 fixes a problem with refraction near the horizon.
  • I've added a closeup photo of the way I connected the tracker to a tripod. I bought a
    small tripod and pulled the center post up through a channel then clamped to it. The
    tripod post is 5/8" diameter. ServoCity part numbers: 3x 585548, 1x 585443, 1x 545360
    and 2x 585596.
  • Notes from a builder, WA7DLG.
  • Gregg, W7GRM, reports the HS-7950TH servo for the SPT400 platform is strong enough even for the Arrow antenna.

Update 2018 July 29: The Tracker is now available using the ESP8266 processor, the same one used in my HamClock. This eliminates the need for the Arduino, ethernet shield and the TP-Link. The wiring diagram and interior view are now just this:

The wiring for the Servo controller, 9 DOF Sensor and tilt and pan servos is the same as in my original design. Note the change from 5 to 3.3 V supply for which the Huzzah EN is grounded. If you use a 5 V supply then leave EN disconnected.

Update 2020 Jun 16: Changes:

The new sketch is here. Set up the Arduino IDE for the Adafruit ESP8266 Huzzah exactly the same as described in the first answer in the FAQ tab of my HamClock project. Use the IDE Library manager to also load the following libraries:

The Tracker functions exactly the same way as described in the original article except how it connects to the network:

Servo City seems to have discontinued the gimbals I used. One builder reports he will try to use this one although I have not tried it myself. Without the extra 5:1 gearing it's not clear whether this can hold an antenna.

Thomas, DL2TW, twinterfeldt at web dot de, has made some code changes, such as a TFT status display and allowing more characters in the WiFi credentials. I've not tried his changnes but you can get his zip file here if you want to check them out.

Let me know what you think!

73, Elwood Downey , WBØOEW