RE: Difference between GPS_EVT_PVT_FIX and GPS_EVT_NMEA_FIX

XavierN — Wed, 04 Nov 2020 09:48:29 GMT

Thank you for the quick answer!

RE: Difference between GPS_EVT_PVT_FIX and GPS_EVT_NMEA_FIX

Håkon Alseth — Wed, 04 Nov 2020 09:40:39 GMT

Hi,

[quote user=""]As I understand it PVT and NMEA are two different ways of expressing the fix data?[/quote]

PVT stands for position, velocity, and time. NMEA is a defined ascii representation of the gps data. If you search for "nmea explained" you should see more detailed information related to this format.

In nrf_socket.h, the pvt struct is a binary representation of the information found in the nmea strings:

https://github.com/nrfconnect/sdk-nrfxlib/blob/v1.4.0/bsdlib/include/nrf_socket.h#L777-L792

[quote user=""]Why are there two different events for those and under what conditions are they triggered?[/quote]

For NMEA, you can select the frames you're interested in, as shown here (where all are enabled):

https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/samples/nrf9160/gps/src/main.c#L140-L144

For pvt, its given as a struct.

The reasons they're split in the driver is because they're also split in the API from the modem (bsdlib) side:

https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/samples/nrf9160/gps/src/main.c#L305

https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/samples/nrf9160/gps/src/main.c#L321

Kind regards,

Håkon