Hi everyone,

I have been having a tough time with my telemetry system in recent months.  To be clear, this USED to work.  I used to be able to connect from my mission planner to the APM over both USB cable and over telemetry radio.  At some point, during the rest of my build out, the APM stopped arming.

I have troubleshot the problem down to a single circumstance, the connection of the 3dr radio using the 3dr telemetry Y splitter.  Please see the attached video for full explanation.

Any suggestions or clues would be very welcome!


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

Join diydrones

Email me when people reply –


  • Solved:  my problem was the either the 3DR power module or the APM 2.6 input for the power module not sensing the battery voltage.  I went into Config/Tuning  and then Standard parameters and searched for BATT.   Then i Disabled the BATT_MONITOR parameter. Now arms up and work good while under 3DR radio.  I found this by looking under FLIGHT DATA tab and clicked on messages, after the barometer calibration the message Low Battery! would come up. This never showed up on the Flight Display.  If your problem is different than mine it might show up there under messages. Hope this helps.

  • Mine would arm up but only so long as the micro USB cable was connected.    Everything would work fine but the minute I pulled out the cable from the 2.6 then it would disarm. Thought is was maybe a voltage issue but not sure. I have the inputs powered separately from the outputs with the J1 jumper removed.

    • Yep, this is quite possibly the same issue. I suspect it is a voltage issue, but I never did figure it out.  if you learn anything, please do let me know.

  • I have sort of a similar problem - did you end up fixing yours.

    Here is my problem:


    • No, I never did hear anything from anyone about this and haven't made any progress.  Sorry.  I will watch your thread for replies as well.

This reply was deleted.


Laurie J. Troy liked Jasper Kueppers's profile
Apr 1
Timothy Miller liked Joseph Udofia's profile
Mar 18