For next years Makerspace at our Middle School we thinking on doing a Near Space Balloon launch.

I love all the telemetry wrapped up in the APM for such a low price, GPS, Mag, Baro, Accel and more not to mention easy exporting to an KLM and other logs.

Since we are already putting a lipo on board to power the camera(s) I was thinking we could also add a APM 2.6 if we could somehow get it to arm and keep it armed to collect the data during flight. Estimating about 90 minutes or so in the air.  One worry I have is would it use all its memory before the 90 minutes was complete?

I can add an Rx to get it armed but won't have motors/esc, If there is a way to arm it and leave it armed without motors is there a list of Advanced params I need to change to make this happen.

If anyone knows of a better telemetry only I can get same price range as APM that would be appreciated to.

I know this is off topic of drones, if there is a better fourm for APM only questions I can move this there.

Thanks again, Ed,

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

Join diydrones

Email me when people reply –


  • Temperature via APM logs:  I don't think there is any way to collect temperature module on the APM/Pix is there? (Rather Easy solution that is for middle schoolers)

    If not I was going to order this and attach to one of the cell phones


    TEMPer2 - , RDing tech
    PCsensor,RDing tech, customized Keyboard
  • Hi Ed I collect my data with a hardkernel odroid-w(8gramms) running minibian with an 16GB SD-Card and mavproxy installed you can forward the data via 3dr telemetry Kit or/and 3/4G mobile network. The first test went about 6hours tracking a work-mate of mine driving to customers. Powerdrain of odroid with 3G and wifi 0,5-0,7A on 5V and APM 0,2A at 5V. Maybe that helps

    Cheers Thomas

    • Moderator

      The $40 tracker might not work very well at altitude, the cellphone system does not point up.

    • Gary, your correct, tracker is just more for recovery, but may break at altitude as its cheap china.  Looking at SPOT tracker too as its more rugged and still cheap and has been used by balloon groups with success.  Thanks!

  • Developer

    Hi Edgar.  You will want a pixhawk, not an APM2.  An APM2 will run out of local storage very quickly.  A pixhawk has an on board SD card that will keep all the details of the flight should you loose telemetry connection with the vehicle. 

    You can just disable the arming checks so the pixhawk starts up working and logging immediately.  Set ARMING_REQUIRE to 0 - see this link

    And then set BRD_SAFETYENABLE to 0 - see this link


    Keep us informed of how you go!  Photos would be great!

    Thanks, Grant.

    • Grant, I do have one question for you.  I fly my 3DR APM on a quad for 15-20 min and my log often has 10+ logs in it before I clear them, that makes me think that the memory may not get full in a 2.5 hr balloon flight if I use my APM using teh default logging.  Please correct me if I am incorrect.


    • Developer

      It very much depends on what logging you have enabled in the log bitmask.  The APM only has 4Meg of storage (the Pixhawk with an SD card can have gigs and gigs!) for logs so 30 minutes of logs is about right but perhaps I log more data.  You can experiment and see how you go.

      Thanks, Grant.

    • Grant,

      I am only going to log Baro/GPS/Accelerometers mask

      I have to use APM because Pix is just to much money to loose, it may fill up memory but thats okay, I'll take what I can.  

      I did a simple test with my APM on my quad, I put the Plane firmware on noticed

      BRD_SAFETYENABLE to 0  was not avail, looks like its PIX only

      But I did set ARMING_REQUIRE to 0 

      After plugging into the computer with USB, power gets to apm, I started MP and I noticed it was not "armed", so I hit the arm button in MP and after a few seconds it disarmed.

      Im not sure this will work.

      Grant I know your busy but if you have a sec can you let me know what I may be doing wrong.


    • Developer

      Hi Edgar. 

      The APM doesn't have a safety switch.  That's why there is no BRD_SAFETYENABLE parameter.

      As your running APM on copter I assume your using the older firmware - AC3.2.1.

      I'm not an expert on copter and it does things differently.  It sounds like you have something in your setup ArduPilot is not happy to auto arm with.  Perhaps the GPS is unhappy?

      Thanks, Grant.

    • Thanks Grant.

      Your correct 3.2.1

      Well what I did was load ArduPlane onto my Team Blacksheep DISCO Quad APM just to "test" this (not to fly my quad of course just to test thi ;))

      So ill order a new APM as long as your reasonably sure I can do these 2 things with the APM by changing the PIDd to 

      1. Have my APM auto "arm" with simply plugging in my USB power plug to run my GPS/APM and have logging start without the need of a RX/Motors/ESC hooked up
      2. Keep it "armed" until the battery or memory fills up or -40 degrees shuts it down, whatever comes first.

      I am looking for an old one on ebay, I don't care what it looks like as long as its working lol :D

      I just did not want o buy it if I cant  use it.

      If anyone has an old one for sale let me know :D

      Thanks, Ed,

This reply was deleted.