Cannot calibrate battery sensor on PixFalcon w/PX4 stack

Ground Control Software QGroundControl
1

I have just started using QGroundControl for the first time as I have a PixFalcon I am setting up and was curious about loading up the PX4 stack.
I have using ArduPilot with APM Planner and Mission Planner for a while with good results.

The first flight was superb with default settings, rock solid and very responsive in Stab, AltHold And GPSHold, but ended very quickly with a battery failsafe.

Checking the battery voltage revealed the PixFalcon battery sensor is reading too low a voltage.

So I spent the better part of an afternoon trying different values in the voltage scaling parameters to try and get a correct reading, but without success.

I then spent hours searching the net, this site and the PX4 site, for any info on battery calibration but could find none.

Is there any info, secrets, tips, tricks, to getting the correct battery voltage readings when using QGroundControl and the PX4 stack.

The Ardupilot stack seems much easier to tweet these readings to get them correct when using APMPlanner or Mission Planner, but of course these can’t be used with the PX4 stack.

Any help would be appreciated.

2

Perhaps someone at the PX4 side might be able help you.

3

Mission Planner has a little calculator thingy for ArduPilot setup. Not sure if we could do the same thing for PX4 stack?

4

Apparently MissionPlanner will not talk to the PX4 stack as all the parameter names are different.

5

Thanks @LuisVale I will try reposting my question there.

As a note, the MissionPlanner method of measuring voltage and putting it into the setup screen is easy to use a works well.
Could this or similar be implemented in QGroundControl?

6

As soon as I saw this thread I added an issue: https://github.com/mavlink/qgroundcontrol/issues/3611. I’ll add it.

7

FYI to anyone reading this thread and using ArduPilot+QGC. I just implemented the voltage/current calculator thingies: https://github.com/mavlink/qgroundcontrol/pull/3629

Still trying to figure out if the same thing is possible for PX4 Stack.

8

FWIW, I am running ArduPlane 3.5.1 with Mission Planner on a PixFalcon, and have been able to calibrate voltage and current reasonably well, though I still find battery RTL’s more of a PITA than a life ring.

Kelly

9

It seems to be a problem with the PX4 Stack.
I was hoping to check out the PX4 stack on this copter but if I can’t get the battery monitor working I might have to go back to the Ardupilot firmware.

10

I’m talking to Lorenz about how to implement the calculators in QGC for PX4 stack today. Should be in a dail build of QGC in a day or so.

11

Thanks Don, I will hang in there with this copter and wait for the update

12

New daily builds are out:

Screen Shot 2016-06-30 at 4.10.52 PM.png1081×815 126 KB

Screen Shot 2016-06-30 at 4.10.59 PM.png1082×814 127 KB

13

Updated the firmware with PX4 master, installed the new QGroundControl and the battery sensor is now calibrated within 0.05 volts.

Great.

Well done and thanks for the efforts.

Mike

14

Great to hear it’s working for you