Designing a Physical Satellite Tracking ...

Designing a Physical Satellite Tracking Widget

Mar 22, 2024

I've been toying with this idea of adding a "Widget" to my Icom 9700. Playing with satellites have always introduced various kinds of software that requires a fully fledged PC connected to my radio. For playing with Leo Satellites you always end up with software for tracking the satellite, controlling the rotator and automatically adjusting for doppler effect. While all of that software works perfectly fine I always wondered if there wasn't a simpler solution which is always available and ready at the radio.

I know there are a few satellite "controllers" available that allow you to do something similar, but I felt that those are either too specific (ie, only this radio and that rotator) or was lacking some features.

My idea around the Satellite Tracking widget is to try and combine everything I need in a single small display. This post outlines the progress I've made so far and the additional items I still want to add.

From a hardware perspective I wanted something that would blend in fairly simple with the radio. Using the Raspberry PI was fairly obvious, but after some searching I found the perfect LCD to pair it with. The 7.9inch HDMI LCD from Waveshare is a very nice small and wide LCD with a resolution of 400x1280 with touchscreen capabilities. Add some 3d printed brackets and its a nice addon onto my radio. The photos don't really do the LCD any justice. Its crystal clear and looks great!

From the software side I've used Raylib for a graphical library. This also means that its cross platform so the widget can in theory run on other platforms. But for now I'm developing it specifically for the Raspberry PI (I'm doing my testing on the Pi4, but in theory others should work).

Currently I'm aiming for the following functionality:

(1) Simple TLE management
(2) Give an overview of upcoming passes (Elevation Graph)
(3) Track a satellite - current AZ/EL, Polar Chart
(4) Track a satellite - send az/el data to rotator
(5) Track a satellite - send frequency info to radio
(6) Update TLE and Transmitter Info from Satnogs DB

I currently have the first 4 items done and working. The interface uses a simple touch screen to navigate the various options. The main overview screen shows the various configured satellites and their upcoming passes. The graph on the right shows a "picture" of the next 12 hours of available passes and gives a clear indication of the elevation.

Based on that I can more clearly plan my day and satellite activities. For the main screen I can select any upcoming satellite pass and get the real time info of that pass as it happens:

For testing I've also added a basic connection to a rotctld service that I'm running that is connected to my current rotator setup. The button with the little guy running, enables the az/el data to be sent to rotctld.

The section I'm currently working on is the radio tracking side. For starters I will be connecting via CI-V to the Icom 9700, but it should be simple enough to also integrate with rigctld to control other radios.

I should have the first test version available for the people that are supporting my software developments in the next two weeks or so, but once the initial test versions are out and tested it will all be made available on Github as open source. (This also minimizes the support overload while its being developed and tested).

I've tweeted a small video clip so you can get the idea of the gui in use.

I've also designed some basic brackets for 3d printing to mount the lcd on the Icom 9700.

The end result came out better than expected :)

Still some tweaking to do on all fronts but happy with the current progress. More updates soon!

And for those waiting on the new OpenTuner release. Its almost ready with support for the new HamTV coming soon on the ISS. It was launched yesterday and I suspect it will be installed somewhere in the next two months. Go check out the page on the BATC wiki for more information.

Thanks for all the support and comments and feedback. Its always welcome :)


Tom - ZR6TG

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