Every now and then it's good to pack light and leave the laptop at home and just enjoy flying. Running out of battery at inconvenient time is however a concern of mine. I just recently finished a project to display telemetry data from APM on Aurora's screen. I'm not particularly proud of the technical side of the implementation, but this seems to work fine.


Hitec's Optima receivers interface with "Sensor station" via I2C, receiver being the master. APM has I2C-bus and it should support multiple masters, but I could never get it working reliably. My solution was to use ATMega88 to receive data via SPI from APM and relay the data to forward by answering queries send by the receiver. The circuit itself is really simple, just the avr, two resistors and a decoupling capacitor.




All the information that could be get from the sensor station are emulated from the data from APM, even including fuel meter, which tells how much mAh are remaining from the rated capacity of the battery. Only thing that I haven't implemented is GPS position and time, since they are not really useful without a map. One nice thing is that on Aurora, you can rename temp and rpm labels. I'm using rpm-1 value for mAh's used and rpm-2 for airspeed. Temp-2 is used to show the current throttle (0-100). Temp-3 and 4 are still left for some other data.


I'm really happy to get this working, since all the important data is available from transmitter screen with one glance and since the APM sends the data via xbee, this is a nice to have backup feature.


If somebody wants to use this too, I can provide sources and schematic later.




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  • Very cool cant wait to get started    Tom

  • Moderator

    Hi Bart,

    in my telemetry board you can found more info here  :


    I have yet implemented mavlink decoding , osd visualization and telemetry on Jeti Box , in my development , I would interface also Aurora9 as second step .

    The board will be ready in a week and share the source to community so the interface on different target is only a problem to develop the driver.

    Now I'm working on some update to mavlink protocol for recive info about motor is armed or disarmed and info about home waypoint or other target ... If you want we can share our development.



  • Very kewl.  I have the A-9, so count me in.

  • @Burt Green: I don't mean MavLink messages, although I did considered tapping to xbee wires and decoding mavlink to get the data. This would however meant more work and I'm lazy.

    Instead, I'm using SPI-bus on APM-board, which is also used to interface with flash "black-box" memory. Good things in this approach is that I can more flexibly get internal data from APM (not limited to data provided via mavlink messages) and the device can be used to extend APM (like add digital outputs etc). The downsides are, that this requires changes to APM code and soldering couple of wires to oilpan, since it does not have connectors for SPI.


    I'll try to clean up the code this night and draw the schematics. I'll send the link as a comment to this post, when I'm ready!

  • Happy to see someone else working on this. When you say "SPI from APM" do you mean the MavLink messages? I had something working on the ground, but first flight was a bust. From that flight my APM has had few problems, but can seem to blane the interface board I build. Seems like a power problem.

    Anyway please post source code and schematic.

    I did decode the GPS Lat and Long from MavLink messages if you want to see it, however it was all for the Arduino Pro Mini.

    You can see my post at http://diydrones.com/forum/topics/telemetry-on-aurora9-transmitter

  • awesome!ive been hoping someone would implement this on APM based on previous hacks.Id be interested in the details as id like to try it with the USB to PC telemetry device.
  • Very nice!

    Just one thing: GPS is pretty useful even without a map in case of a "missing plane" you will have your last ccordinates which will ease the search in case it crashes somewhere far away...

  • This is great!  Yes please do post source and schematics.

  • Great achievement !

  • Fantastic, I will look forward to seeing and using some of this code. Maybe with gps attached to tx you could have a "find me" option after a crash. James Bond type of radar tracking signal to find the plane :)

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