No GPS fix on

[SP]

Hi,

I made 20 x prototypes with a nRF9160 SICA B1 (Modem FW 1.3.4) and I use the SDK nRF Connect version 2.2.0.

On few boards, I can't get satellites fixed after 5 x minutes of searching and you can see below the last trace that I received :

PRN:16 | C/N0:40.9 | In Fix:0
PRN:18 | C/N0:42.5 | In Fix:0
PRN:26 | C/N0:39.4 | In Fix:0
PRN:5 | C/N0:30.6 | In Fix:0
PRN:2 | C/N0:24.4 | In Fix:0
PRN:29 | C/N0:31.7 | In Fix:0

Signals seems good for PRN 16, 18, 26 and 5 (> 30db/Hz).

The matching was done on this prototypes and many of this works perfectly (they can get GPS fix after 1 x minute).

I don't undestand why some samples doesn't get GPS fix !

I added this code on the search_start() function to reduce accuracy : 

uint8_t use_case = NRF_MODEM_GNSS_USE_CASE_MULTIPLE_HOT_START;
        use_case |= NRF_MODEM_GNSS_USE_CASE_SCHED_DOWNLOAD_DISABLE;
        use_case |= NRF_MODEM_GNSS_USE_CASE_LOW_ACCURACY;
	err = nrf_modem_gnss_use_case_set(use_case);
	if (err) {
		LOG_WRN("Failed to set GNSS use case, error: %d", err);
		return;
	}

Do you have aby idea about this issue ?

Can you confirm me whether the code above reduce accuracy ?

Thanks in advance

[Turbo J]

Try waiting for 30 minutes.

Download of the GPS Almanac can take >15 minutes when using GPS only.

[SP]

Thanks for your reply.

Almanac are already downloaded by assistance minimal at the start of application.

after 10 x minutes of GPS searching, here the last log : 

PRN:7 | C/N0:42.0 | In Fix:0
PRN:27 | C/N0:40.8 | In Fix:0
PRN:10 | C/N0:35.5 | In Fix:0
PRN:18 | C/N0:32.6 | In Fix:0
PRN:8 | C/N0:39.5 | In Fix:0
PRN:26 | C/N0:24.6 | In Fix:0
PRN:21 | C/N0:26.2 | In Fix:0
PRN:3 | C/N0:24.6 | In Fix:0

It's the same thing !