Not many people know but we have an piece of open source software for controlling an Antenna Tracker.  It's been built by Tridge (Arduplane lead developer) for use in the outback challenge.

Sadly we have no documentation and, as far as I know, nobody except Tridge has used it.  Still given Tridge's track record on building great software I suspect it works well and if it doesn't, I'm sure we can fix it.  So to not let this piece of code go to waste, I'd like some help from people who are interested to give it a try and help me figure out how it works.

Here's the little that I know:

  • It runs on any of our supported board (APM1, APM2, PX4, Pixhawk, Flymaple and perhaps VRBrain)
  • For APM1/APM2 users building the code is as easy as opening our hacked ArduinoIDE and selecting File > SketchBook > Tools > AntennaTracker and then building in the normal way.  For PX4/Pixhawk, our autobuilder doesn't automatically build a binary but I can provide one if people are interested.
  • It can control a Pan and Tilt gimbal like this or this found on
  • It may or may not require a GPS
  • It must somehow receive vehicle position updates from the ground station which has the telemetry radio that is connected to the vehicle. Maybe through a USB cable.  Tridge probably uses the python ground station, MAVProxy, to passthrough the vehicle position data to the AT but perhaps we can get MichaelO to build out a similar feature in Mission Planner.
  • I imagine this antenna tracker could also be used to keep a camera focused on the vehicle which might be good for easing the burden on creating videos of our vehicles.

So if you want to give it a try please do and stick any findings, questions or issues below. Alternatively Issues can go into the issues list.

I'll start sticking things into the wiki as they become clear.

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Thanks for the reply Randy. Is it possible for the tracker to learn its location from the Home location so the lat/long wouldn't need to be manually entered?

What do you think of the idea of using the onboard baro to adjust the GCS height via GND_SET_OFFSET?


I think the idea to use the vehicle's home location if the AT doesn't have a GPS and the location parameters haven't been set is a good ease-of-use enhancement.  Feel free to add the home location enhancement to the to-do list.

Using the AT's baro to adjust the vehicle's ground pressure param to take account of baro drift is also a great idea.  I'm sure Tridge updates that ground-pressure value on long flights, i don't know how exactly but I'd suspect the AT is used somehow.

Thats what I did with mine initially./

First 3D fix it sees on startup with more than 8 sats it records as Tracker Base, I have a menu option to reset it if it doesn't look right, Height was sometimes a bit off. Just needed to make sure the multicopter was next to the Tracker on startup.

Any idea what kind of control unit for the pan and tilt in the image above is?

I am trying to operate two servos for  the antenna tracker using mini arduino and the MP. It is working well  at the calibration section, however, while I am running a flight log, the servo is not responding.

does it works only at online flight or thereis some way to make it work offline?

mini arduino?  not sure quite which flight controller that is..

it's only controlling the antenna pan/tilt servos, using data from the mission planner.

I can not seem to get this working. The tracker just keeps doing it's sweeping scan.
I'm setting it up with an APM 2.5.2 and a RMRC plywood gimbal. I'm only doing video Rx for now. The tracker APM is connected to the laptop via USB. The 3DR module is on another port.
I connect the aircraft to MP via telemetry. I then attempt to feed the tracker a Mavlink stream via the USB port by using CTRL+F > Mavlink. I select the USB port and 115,200 baud rate. I click connect, but nothing seems to happen. There isn't any indication if it connected. The tracker just continues it's scan sweep.
I'm i missing a step?
How is one supposed to change the tracker modes since MP is connected to the plane not the tracker. Maybe to instances of MP can be open at once?


I've been off looking at at AC3.2 mostly but I started back at the Antenna Tracker again a bit today.  I found that I needed to set the PROXY_MODE parameter to "1" so that messages are forwarded on from the Pixhawk I'm using to control the antenna tracker servos to my mission planner ground station.  I've updated the wiki page here.

I can now connect to the vehicle with the mission planner (passing through the AT) including reading parameters, etc.

There's still some weirdness, like the mission planner is complaining on it's console that it's seeing a lot of messages that aren't meant for.  Basically I think there's some IDs being set incorrectly during the message forwarding.

I can tell that the Pixhawk on the AT is receiving the position updates from the vehicle but I haven't checked if it will move the servos correctly or not yet.

At the moment, I also don't see a way for the MP to send messages to both the AT and the vehicle so I think we will need MichaelO to enhance the MP.  I think he'll be ok to do that for us though.

Thanks for the reply but I think you are msi understanding my configuration. I am not using the tracker for telemetry, only video. The telemetry goes straight to the GCS via the 3DR dongle. I need to pass that data on to the antenna tracker. I think this is what Michael meant when he said to use CTRL+F.

I did my first test with the Antenna Tracker today.  It does indeed work!  I did a distance test after making the video and flew my copter out about 500m.  My TX/RX failsafed at that point and the vehicle came home so I'm still unsure of the maximum telemetry range but I now know that it's further than my TX/RX.  I was actually quite surprised that my TX failsafed that soon.. it happened just as I placed my TX down on a table so perhaps the TX's antenna was suddenly at a bad angle or something.

Thanks Randy, it's great to know it actually works. My setup is different and I wasn't able to get it to lock on. I'm trying to use an APM as a video antenna tracker, not telemetry. So the telemetry info needs to get passed along from the GCS to the tracker. CTRL+F didn't work for me. Maybe I should try APM planner 2.0?
Has anyone gotten it to work without using proxy mode?

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