Discussions

Developer

figuring out the Antenna Tracker

Posted by Randy on July 25, 2014 at 8:01pm

3691139590?profile=originalNot 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 servocity.com.
  • 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.

You need to be a member of diydrones to add comments!

Join diydrones

Tags: antenna, obc, open, source, tracker
Email me when people reply –
Follow

Replies

          • Paul Edwards > Ted P October 11, 2015 at 8:54pm

            Ted,

            That is great! I would really appreciate it! I'm going to just remove the mavlink connection all together and plug a GPS straight into it. Thanks again!

            Paul

            • Ted P > Paul Edwards October 11, 2015 at 9:01pm

              Here's the changed file. You'll have to recompile the software according to these instructions:

              http://dev.ardupilot.com/wiki/building-the-code-onlinux/

              Also, I'm not sure I fully grok your setup, but the tracker needs MAVLINK GPS messages to tell it where to point TO. For my setup, I wrote some software to take a GPS location and convert it into a MAVLINK IGPS message and send it to the tracker. The tracker thinks it's getting a vehicle GPS message and points in that direction. If you are moving the tracker, it will stay locked on the target GPS location.

              Good Luck,

              Ted 

              tracking.pde

              • Paul Edwards > Ted P October 11, 2015 at 9:06pm

                Much appreciated Ted. I'm with you - I am moving the tracker but am appreciative to have something to start with. I'd imagine i'll be doing something similar to convert over GPS location to Mavlink GPS but I'm very thankful. The quest continues!

                Paul

  • Keith G October 6, 2015 at 12:02am
    Another issue. I just bought two rfd900+ radios. Changed the net ids so the 3dr radios are on 50 and rfds are on 100, ramped the power up, hooked one 3dr to the tracker and one 3dr radio to the pc for a link. Hooked another rfd900+ to the tracker and one on the plane for a link. I think the Rfd's are stomping all over the 3drs because the connection is quite spoty at best. How do I get around this?
    • Keith G > Keith G October 11, 2015 at 9:12pm
      Randy solved this. If you use rfd radios, they draw too much power and will cause your board to brown out.
  • Keith G October 5, 2015 at 9:59pm

    for some reason the compass is slowly turning in mission planner. did several calibrations but it wont stop. it's like the second hand on a clock. not sure why this started. nothing changed from when i used it months ago...except firmware. any ideas

    • Keith G > Keith G October 5, 2015 at 10:30pm

      also, the pitch is stuck at 45 degress again. i thought this problem was fixed. please help. over a year and still i cant get it to work,

  • kiki October 3, 2015 at 1:19pm

    Hi, 

    My setup is : apm2.5, NMEA gps, 3DR telemetry

    and 2 servo's for tilt/yaw.

    Tracker FW ver.: 0.7.3

    If i go to Initial Setup > Antenna Tracker in MP(1.3.28), then i can move my servo's.

    But as stand-alone or hooked up to MP in AUTO-mode my tracker doesn't move an inch. 

    and on the HUD it says DISARMED... do i have to arm it ? 

    I do see the red line move in MP when i move it by hand.

  • Toby Mills September 20, 2015 at 6:27pm

    Hi All

    Going around in circles a bit, I decided to drop my bid to get AntennaTracker working as part of a multinode network and focus on trying to just get it working first.
    I've read and tried all the suggestions on all 48 pages of this thread but not having a lot of luck.

    I can get it connected via USB and then a radio link to my quad from the AT and both are appearing in Antenna Tracker.
    However the AT just doesn't seem to behave at all.

    Pitch seems ok. but I can't get YAW to track.

    I have an eagle eyes tracker and have set it to 180 degrees precisely. The upper and lower limit of the servos go to 180 degrees.

    I can see the orange line pointing in the correct direction but the red line is way off and the yaw servo doesn't move to try and bring it into line.
    But then if I tile the AT, it suddenly starts moving.
    So something is working, but yaw just seems eratic and not at all close to what it should be doing,

    I have tried

    • reversing the yaw servo.
    • re-calibrating both the compass and accelerometers many many times,
    • reloading old firmware
    • mounting the APM2.5 flat to the bottom of the AT (instead of to the back using Pitch90).
    • plugging radio into laptop and sending data to AT using USB mavlink forwarding.

    sometimes it looks like its about to work right and then it stops mid pan or overshoots and then ends up pointing in some weird direction.


    I can see the red line in MP is showing correctly the direction the AT is pointing but its not trying to move the servo to move to the orange line (which is also correct).

    I can't seem to figure out why it will not track.

    I have standard servos.

    APM 2.5

    internal compass, external GPS.

    Any suggestions on what might be up would be great, happy to post a video or any logs if that would help.

    I really want to get this going so that I can figure out the multinode networking and then post instructions on how to set that up.

    • Jakub Oller > Toby Mills September 21, 2015 at 5:33am

      Hi,

      describe your tracker (servo type and configuration) and post your PID settings and FW version

This reply was deleted.

Activity