BG95-M3 GNSS can't get location

IoT Modules LPWA Module
1

Hi everyone,

I have a BG95-M3 with which I want to get the location using the GNSS. To do so I did :

  • AT+QGPSCONFIG=“gnssconfig” = 3 (as I am located in Europe)
  • AT+QGPS=1
  • AT+QGPSLOC? gets me Error 516 which description is “No fix”.

Even after waiting 15 minutes outside I still got the Error 516 while I got GSV sentences :
GPGSV,3,1,11,03,00,000,28,10,00,000,28,15,00,000,26,21,00,000,28,16D
GPGSV,3,2,11,23,00,000,27,24,00,000,28,25,00,000,27,26,00,000,27,16E
GPGSV,3,3,11,27,00,000,26,28,00,000,27,30,00,000,29,152

Is there something that I missed in the configuration or something else to do to get the location ?

Thank you ?

2

Hey Thomas_Allain,

I have noticed that with GPS module that with only a limited number of satellites in range, reducing the “Accuracy” rating can increase the chances of getting a fix faster. I have observed that on a cold boot it can take ~5minutes for a “High” Accuracy fix and <2minutes for a “Medium” fix.

Generally the accuracy rating mentioned in the GNSS Application note (V1.2) seem to be a “Worst case” scenario- so keep this in mind.

On testing with a BG95-M2 I also have observed a significant performance improvement in later versions of the firmware- so ensure your module is up to date. (This is not something I have measured and is more of an observation)

3

Hi james,

Which firmware version are you currently using?

Thanks

4

I don’t know why your GSV sentences showed zero elevation and azimuth. If these 2 fields are zero or missing, that satellite will not be used for position calculation no matter how high the CNo is.

Moreover your CNo’s are quite low only in the range of 2x dBHz. To get a fix you need 3 to 4 satellites of CNo’s in the range of 35dBHz.