Timing issue when GPS used with NB-IoT

[paul_tanner]

In SDK 1.4 we combined the udp and GPS examples and the result is unstable.

I think this could be because once enabled by RRC mode == Idle, GPS keeps going forever.

After getting a fix we want to send the data with location.  At this point it seems there is often a clash where GPS is fetching the next location.

I think we need to switch GPS off, send the data, delay a while and then switch it on again to get the next fix.

What is the proper way to do this pls?

Regards.

[helsing]

Sorry for the delay.

You may read about Continuous navigation mode here:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.5.0/nrfxlib/nrf_modem/doc/gnss_extension.html#fix-interval

'Continuous navigation mode is engaged by setting the fix interval to one.'

[paul_tanner]

Thx. Will try that but in the mean time I read something else here:

https://devzone.nordicsemi.com/f/nordic-q-a/57448/nrf9160-gps-hangs-when-starting-after-stopping

Specifically, there is apparently a GPS driver in the SDK.  The provided GPS example doesn't use it but would this not be a better approach than just polling for a fix?

[paul_tanner]

I tried something else and it worked.  Just before sending data I stopped GPS with gnss_ctrl()

after sending I waited for LTE idle before restarting.  Error messages no longer seen.

Solution.