Ublox GPS/Compass Combo causes APM power down

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1

I am connecting a Ublox GPS compass combination to an APM 2.6, everytime I connect both cables (i2C and GPS connector) it causes the APM to power off, all lights go off and MAVlink disconnects. Anybody any ideas??

Thanks in advance (I hope!!!)

2

@mwestcrew,
Try connecting only one cable at a time to help identify which part of the modules is causing the problem. Start with the GPS first and if the APM does not shutdown, make sure that the GPS red power led is on.
If the module does not shutdown the APM with the GPS plugged in, then the problem is most likely with the compass module.
I assume that it is a 3DR GPS/compass module and you used the cables that were provided with the module?
Regards,
TCIII GM

3

Thanks for your reply.

I tried to use some logical fault finding…

Either one of the cables on it’s own does not cause a power down, adding the second whichever one does.

Cables are original, supplied with the unit.

4

No power light on the GPS board.

5

@mwestcrew,
Sounds like you either have bad cables (not likely) or a defective GPS/compass module.
I suggest that you contact 3DR customer support at help@3drobotics.com for further assistance.
Regards,
TCIII GM

6

So…purchased new 3DR Compass/GPS and fitted it, now all powers up and seems fine BUT when I do the compass calibration it appears to work and the offsets are reported at the end of the 60sec time out but the pre-arm checks are reporting Compass Not Calibrated. I have looked in the standard parameters and all three offsets are showing as zero. Do I need to enter the offsets that are reported or is something else going on.

7

I’m having the exact same issue. When I connect both cables at the same time the APM powers down. When I only connect MAG a red light turns on in my GPS/Compass module. When I only plug GPS no lights turn on but at least the APM doesn’t power off.

Is a defective module the only explanation to this?

8

@Arthurso,
It is interesting that you get the red power led when you plugin just the compass cable as the module is supposedly powered by +5vdc coming through the GPS cable.
Regards,
TCIII GM