nRF9151 GNSS issue

[Majid Bahmani]

I hope this message finds you well.

I am currently working on a project using the nRF9151-DK Evaluation Board and have been testing GNSS functionality in various environments with different antennas and configuration settings. However, I am experiencing significant difficulties in obtaining GNSS fixes:

• When both LTE and GNSS are enabled, the GNSS receiver does not seem to acquire any satellites, even after waiting for more than an hour. (Tested with or without external antenna) 

• When LTE is disabled, a location fix is occasionally received, but only after several minutes and very sporadically.

Additionally, I could not find any AT command or documented method to configure or enable additional GNSS satellite systems such as GLONASS, Galileo, BeiDou, SBAS, or IMES. It appears that only GPS and QZSS are enabled and supported by default.

Could you please confirm:

• Whether nRF9151 GNSS supports additional constellations such as GLONASS, Galileo, SBAS, BeiDou, or IMES?

• If so, how can I configure and enable them?

For your reference, here are the AT commands I am using to enable GNSS and obtain a fix:

AT+CFUN=0
AT%XSYSTEMMODE=1,0,1,0
AT+CPSMS=1,,,"00000001","00000011" // tested with and without this command
AT+CFUN=1
AT%XMAGPIO=1,0,0,1,1,1550,1600 // tested with and without this command using various ranges
AT%XCOEX0=1,1,1565,1586 // tested with and without this command
AT#XGPS=1,0,0,0

Note: I am not using nRF Cloud for this project and would prefer a standalone GNSS solution.

Thank you in advance for your support and clarification. I look forward to your response.

Best regards,

Majid Bahmani

[Michal]

Hello Majid,

Whether nRF9151 GNSS supports additional constellations such as GLONASS, Galileo, SBAS, BeiDou, or IMES?

If you look into the datasheet, we only specify GPS and QZSS both in the key features and GPS receiver pages.

When both LTE and GNSS are enabled, the GNSS receiver does not seem to acquire any satellites, even after waiting for more than an hour. (Tested with or without external antenna) 

I don't know what kind of software you are running, but check out GNSS priority modes. If LTE is running very often and has a priority than it may interrupt GNSS before getting a fix.

When LTE is disabled, a location fix is occasionally received, but only after several minutes and very sporadically.

Is it only for the first fix or every fix takes so much time? You could test out low accuracy mode to see if it gets quicker and if the error in that mode is acceptable.

Best regards,

Michal