Here+ RTK GPS with many errors

Hi everyone,

after connecting the drone and wait for all sensors to work fine, then connecting through NTRIP reaching RTK fix after 3D fix and float, then upload the survey mission to Pixhack Cube, I armed in loiter, then auto to start the mission. Some seconds after the first waypoint if I remember well, begun the problems as you can see in the log I attached in the link below which are Bad GPS health, bad compass health, GPS glitch etc…

Actually was the day before when all the problems begun. I was flying in loiter testing my leddar one range finder and then lost GPS signal after some minutes of flying good, then I landed in stabilize and realized the RTK Here+ had no lights on!!! lights had gone off!! Then, I disconnected the battery, back on, and worked again. Flew again and and few time later the same problem. this problem has begun after 5 or 6 good flights with this Here+ RTK GPS with good results.

I have to mention that I have already changed the Here+ RTK for my old and good M8N and works as usual, very good, so it means has nothing to do with the flight controller or whatever.

Before I contact the reseller I would like to ask the experts about this serious problem, specially @proficnc to proceed the right way.

the BIN log is here and I attached a picture of my drone so you can see the position of the GPS which is 21 cm away from the nearest motor.

thanks in advance.
Javier Beringola

What devices do you have plugged into the carrier board?
And can you check for any damage to the gps connector?

Have you contacted your reseller for assistance?

Sorry for so many questions

As the lights are going off, it would indicate a power issue of some sort.

Is it possible for devices connected to the carrier board to affect GPS performance? I’m currently investigating RTK GPS issues on a rover I’m using that has a TX2 connected to the carrier board and I’m wondering if it’s possible that this could be the reason.

Hi and thanks for replying.

I contacted the reseller and asked this:

Good Day Javier,

A tech from Hex has checked the log. Please see the message below.

He was asking if the sensor which connected to the Telem 2 port on FC was powered by the flight controller? Or it was powered directly from the battery? He asked this because he was afraid of strong current.



And I answered this:

Hi Thomas,

The GPS is connected straight to GPS1 port in Pixhawk Cube flight controller. In TELEM2 is connected the Leddar One sensor, and the telemetry module is connected to TELEM1. No more sensor connected to FC. I don’t understand how or why someone wants to connect a sensor to the battery.

The only devices connected to the battery are the video transmitter and the gimbal but the transmitter is connected through a 12V BEC just to avoid this high current and prevent snow in the screen. The gimbal is connected straight to the battery, no BEC.

Tell the tech that everything was fine before begun the problems and now everything is working fine with the M8N GPS connected to GPS1 as always did.

Thanks for helping.

An about your questions @proficnc the connector is good.
And about power issue, now everything is working fine with the GPS M8N as usual.


Very good!!!
Glad to hear it’s working


WelI, I think you misunderstood something.

Nothing is working but my old GPS M8N which I’m using now to working on. I replaced the broken Here+ RTK by my old M8N which proves that there is nothing to do with the Cube, electromagnetic interference etc.

The here+ RTK doesn’t work, is supposed to be in the reseller facilities by now and no news.

Very disappointed with this. Hope to sort it out soon.

Thanks for replying anyway.

Oh :frowning:
Thomas will sort you out


Hi. Thomas sorted it out very professional.

Besides I want to confirm that the problem with the GPS had something to do with the leddar one range finder. After the problem one year ago I stopped using the range finder till now. I tested with another Here+ gps and same problem, gps full disconnected. The problem is cause by this range finder. It is very strange that there is no more reports about this issue.