RE: Unable to get GPS fix with GPS samples

Didrik Rokhaug — Mon, 29 Nov 2021 13:56:32 GMT

Hi,

Based on the log from the GPS sample, it doesn't look like the DK was able to receive strong enough signals from the satellites.

In the following NMEA sentence, we can see that it has found 2 satellites (PRNs 1 and 31), though the signal to noice ratio is too low for the GPS to calculate their elevation or azimuth.

$GPGSV,1,1,2,1,,,25,31,,,24,1*64

The GPS would also need to track at least 4 satellites to produce a fix.

The AGPS sample doesn't print the satellite SNRs, but my guess is that the same thing happens. the SNR of the satellites it finds are too low, and it finds too few satellites.

Getting a fix indoors is generally quite hard (not completely impossible, but also not something you should expect to happen). When testing outdoors, you should also try to be in a spot with a clear view of the sky, and as little as possible obstructing the view of the horizon. Tall buildings can create the same problems as a deep canyon.

Best regards,

Didrik