ARK RTK GPS not getting RTK fix

WARGRaph · August 12, 2022, 1:39pm

Hello everyone,

I bought an ARK RTK GPS to profit from an F9P GPS Module while still using CAN.
When I connect it to a Matek H743 Slim running ArduCopter v4.2.1 and start sending correction data I get from an local NTRIP server, it doesn’t go to rtk Fixed.
When I connect it to a Pixhawk4 Mini running PX4 (unsure what version right now) and start sending correction data I get from an local NTRIP server, it goes to rtk Fixed.

A Here3 connected to the same H743 goes to rtk Float easily. Even when both are connected, the Here3 will go to rtk Float, the ARK RTK GPS stays at 3D Fix.

Any Ideas what could cause it and what could fix it?

Thanks and kind regards.

WARGRaph · August 15, 2022, 5:09pm

After quite some debugging, I found out that the ARK RTK GPS expects the ardupilot.gnss.MovingBaselineData message instead of the uavcan.equipment.gnss.RTCMStream, I will contact the developer as I want to use it as a single GPS and not in a moving baseline config.

alexklimaj · January 3, 2023, 7:19pm

Hi Raphael,

I have updated the firmware to use ardupilot.gnss.MovingBaselineData or uavcan.equipment.gnss.RTCMStream.

github.com

PX4/PX4-Autopilot/blob/main/src/drivers/uavcannode/uavcannode_params.c#L63-L80


      
          /**
           * Enable MovingBaselineData subscription
           *
           * @boolean
           * @max 1
           * @reboot_required true
           * @group UAVCAN
           */
          PARAM_DEFINE_INT32(CANNODE_SUB_MBD, 0);
          
          
/**
           * Enable RTCM subscription
           *
           * @boolean
           * @reboot_required true
           * @group UAVCAN
           */
          PARAM_DEFINE_INT32(CANNODE_SUB_RTCM, 0);

You will want to update the firmware and set CANNODE_SUB_RTCM to 1.

reversedpuppy · March 17, 2024, 7:05pm

Hello!

I seem to be running into same problem, Using the ARK RTK GPS Rev 3 with on my Pixhawk 6x running ArduCopter. When I start sending correction data via NTRIP in mission planner, The GPS stays in 3D fix.

Did you discover a work around that works with Ardupilot/ArduCopter?

I’m considering Forking Mission Planner to attempt to modify the “InjectGpsData” function to send the “ardupilot_gnss_MovingBaselineData” message instead of the other one, but I’m not confident that I can figure it out.

In any case I haven’t been able to configure the ARK RTK GPS to get RTK Fix at all, and I can’t test on a different FC firmware without re-flashing my pixhawk 6x. I’m willing to switch to PX4 firmware, but our project heavily relies on Mavproxy, so I’m motivated to get this to work with ArduCopter.

Any guidance in regards to calibrating the ARK RTK GPS to work with NTRIP and ArduCopter/Mission Planner that would be greatly appreciated!

Thanks.

WARGRaph · March 18, 2024, 9:13am

Hi,

we switched to a different GPS solution, so it’s been a long time, but as far as I can remember it worked after updating the firmware as Alex described and setting the parameter.
If that doesn’t help, Alex seems to be very responsive regarding such problems.