GPS RMC and pvt parsing

RE: GPS RMC and pvt parsing

Bjørn Kvaale — Tue, 16 Jul 2019 05:44:53 GMT

Great to hear that you are making progress! Is there anything else I should ask about internally regarding RMC sentencing & parsing the NMEA sentences?

RE: GPS RMC and pvt parsing

Tron — Mon, 15 Jul 2019 08:12:36 GMT

I have been testing, and i get fix relatively fast using RMC sentences. The GPS driver doesn't deliver a fix using the RMC sentences, it seems it uses only GGA to deliver fix events.

In order to use RMC, I will have to manually parse the incoming NMEA sentences by hand.

RE: GPS RMC and pvt parsing

Tron — Mon, 15 Jul 2019 07:06:25 GMT

When I look in the nrf9160_gps.c file in the drivers section of my project, I see that by default only gga sentences are enabled,

In the c file, I see

#ifdef CONFIG_NRF9160_GPS_NMEA_GSV
nmea_mask |= NRF_CONFIG_NMEA_GSV_MASK;
#endif
#ifdef CONFIG_NRF9160_GPS_NMEA_GSA
nmea_mask |= NRF_CONFIG_NMEA_GSA_MASK;
#endif
#ifdef CONFIG_NRF9160_GPS_NMEA_GLL
nmea_mask |= NRF_CONFIG_NMEA_GLL_MASK;
#endif
#ifdef CONFIG_NRF9160_GPS_NMEA_GGA
nmea_mask |= NRF_CONFIG_NMEA_GGA_MASK;
#endif
#ifdef CONFIG_NRF9160_GPS_NMEA_RMC
nmea_mask |= NRF_CONFIG_NMEA_RMC_MASK;
#endif

And seggeg greys out the not defined, and I see that only GGA is enabled. If I in my prj.conf defines the variables as described above, I see that RMC is enabled, but GGA is not.

RE: GPS RMC and pvt parsing

Bjørn Kvaale — Fri, 12 Jul 2019 07:33:23 GMT

I cannot see any mention of CONFIG_NRF9160_GPS_NMEA_RMC or CONFIG_NRF9160_GPS_NMEA_GGA in the gps code. The only code I can see that may be relevant is the following in init_app:

	u16_t nmea_mask     = NRF_CONFIG_NMEA_GSV_MASK |
			      NRF_CONFIG_NMEA_GSA_MASK |
			      NRF_CONFIG_NMEA_GLL_MASK |
			      NRF_CONFIG_NMEA_GGA_MASK |
			      NRF_CONFIG_NMEA_RMC_MASK;

Regarding the quicker GPS fix, I have asked about this internally & will get back to you soon. It seems we are asking an external expert for some help regarding this.