GPS here+ plus rover is not getting detected

[siddyyagno3]

I have a Here plus rtk gps. The rovers gps module, when connected to pixhawk 2 cube and loaded with px4 stable is not locking to gps. I tried leaving it out for half hour. It is blinking blue light and GPS count is 0. But if I flash it with ArduPilot it is locking in seconds. Am I missing some parameter change.
NSH command GPS status
NuttShell (NSH)
nsh> gps status
INFO [gps] Main GPS
INFO [gps] protocol: MTK
INFO [gps] port: /dev/ttyS3, baudrate: 38400, status: NOT OK
INFO [gps] sat info: disabled, noise: 0, jamming detected: NO
nsh> gps status
INFO [gps] Main GPS
INFO [gps] protocol: MTK
INFO [gps] port: /dev/ttyS3, baudrate: 38400, status: NOT OK
INFO [gps] sat info: disabled, noise: 0, jamming detected: NO
nsh> gps status
INFO [gps] Main GPS
INFO [gps] protocol: UBX
INFO [gps] port: /dev/ttyS3, baudrate: 38400, status: NOT OK
INFO [gps] sat info: disabled, noise: 0, jamming detected: NO
Also, I wanted to know that I can set the RTK survey in accuracy to lowest 0.5. So is this parameter is congruous to the overall accuracy of the setup. Or leaving the setup for more time will eventually increase the accuracy to 10cm level.

Thanks in advance.
Regards,
Sidd

[LorenzMeier]

Which port do you have it connected to?

[siddyyagno3]

GPS 1 port on hardware pixhawk2 cube

[LorenzMeier]

@bkueng Anything that comes to mind?

[mhkabir]

Potentially related : #9461 (comment)

[tops4u]

@siddyyagno3 try >gps stop / >gps start if needed 2-3x and check if your GPS is then found. If so, we may have the same Problem (#9461). Also it may work prior to 1.7.4.

[siddyyagno3]

@tops4u tried the gps stop gps start didn't help. Should I try rolling back the firmware to pirior to 1.7.4

[siddyyagno3]

I tried rolling back to 1.70 didn't help.

[siddyyagno3]

@bkueng @mhkabir @LorenzMeier
Can I rule out that issue is due to configuration as in guide "The PX4 GPS stack automatically sets up the u-blox M8P modules to send and receive the correct messages over the UART or USB, depending on where the module is connected (to QGroundControl or the autopilot)."
So, It might not be because i might have changed some config in ublox center.
Also, When the rover module is connected using usb it is detected as rtk.

[bkueng]

So, It might not be because i might have changed some config in ublox center.

Most likely not, but you can try resetting it to factory defaults.

[siddyyagno3]

@bkueng Tried resetting the settings that didn't help. Then I did a Firmware Update (I had already tried both 1.30 and 1.40 of rover and base with legacy firmware update option in ucenter) this time using the Firmware Update option instead of legacy firmware update then I tried changing the Baud rate to 115200 in message view>UBX>CFG>PRT which finally resulted in detection and GPS Lock: 3D Lock.

But When I tried nsh> gps status protocol is showing as Ashtech not UBX. Also I tried restarting gps with

gps start -d /dev/ttyS3 -m ubx -b 115200 -r
gps error failed to instantiate object

[bkueng]

I got my hands on a Here+, which is attached to a Pixhawk Pro. It works fine when flashing stable.

But When I tried nsh> gps status protocol is showing as Ashtech not UBX

It means it's using the NMEA protocol instead of the u-blox protocol. This should not happen if you use the default config.

gps error failed to instantiate object

The board is probably out of memory. A reboot will help.

[siddyyagno3]

Found the problem and Murphy was involved so the issue was with the Pixhawk2 cube carrier board's faulty gps port, some internal wiring and probably inadequate soldering. I found a spare DF13 connector and connected it to nice old pixhawk and everything was working. I was banging my head on configuration or gps hardware but both were fine. Quality should be ramped up on Pixhawk2 cube carrier boards. Still could not get the 3d RTK Fix but 3D rtk float made me happy. Will be changing the setup to improve signal strength.
Thanks for the help and sorry for inconvenience.

[bkueng]

Glad to see that you found it, thanks for letting us know.