Unable to get GPS location to work on BG93M3 PCIE

IoT Modules GNSS Module
1

Hello everyone. I am having some difficulty with getting GPS location with my BG93M3 module

Hardware: BG95M3 Mini PCIe
Firmware: BG95M3LAR02A03_BETA1110A
Issue: GPS state not changing from 3 (WWAN loaded) to 4 (GNSS loaded) after AT+QGPS=1,1,0,1

Initialization Commands

  1. AT - Check module ready
  2. AT+CPIN? - Check SIM card status
  3. AT+CMEE=2 - Enable verbose error reporting

GPS Configuration Sequence (Following Quectel GNSS Application Note V1.3)

Step 1: Set GNSS Priority Mode (CRITICAL - MUST BE FIRST)

AT+QGPSCFG="priority",0,1
  • Purpose: Set GNSS priority mode (0 = GNSS priority, 1 = save to NVRAM)
  • Expected Response: OK
  • Verification: AT+QGPSCFG="priority" → Should return +QGPSCFG: "priority",0,3 (state 3 = WWAN loaded, will change to 4 when GPS starts)

Step 2: Configure GNSS Constellation

AT+QGPSCFG="gnssconfig",1
  • Purpose: Configure GNSS constellation (1 = GPS+GLONASS)
  • Expected Response: OK
  • Note: Takes effect after reboot

Step 3: Configure NMEA Output Source

AT+QGPSCFG="nmeasrc",1
  • Purpose: Enable NMEA output for AT+QGPSGNMEA commands
  • Expected Response: OK

Step 4: Configure GPS Antenna

AT+QGPSCFG="antennatype",1
  • Purpose: Configure active antenna (1 = active antenna)
  • Expected Response: OK or +CME ERROR: 501 (may not be supported on this firmware)
  • Note: GPS may still work with default antenna settings

Step 5: Enable XTRA Feature (Assisted GPS)

AT+QGPSXTRA=1
  • Purpose: Enable XTRA (Assisted GPS) for faster fixes
  • Expected Response: OK
  • Note: Takes effect after module reboot

Step 6: Clear Assistance Data (Cold Start)

AT+QGPSDEL=0
  • Purpose: Delete all assistance data for cold start
  • Expected Response: OK

Step 7: Ensure GPS is Off

AT+QGPSEND
  • Purpose: Ensure GPS is off before starting
  • Expected Response: OK or +CME ERROR: 505 (GPS already off - this is OK)

Step 8: Verify No Active Data Connection

AT+CGACT?
  • Purpose: Check if PDP context is active
  • Expected Response: +CGACT: 1,0 (inactive) or +CGACT: 1,1 (active)

If PDP is active, deactivate:

AT+CGACT=0,1
  • Expected Response: OK or ERROR (if fails, try detaching first)

If deactivation fails, detach from network:

AT+CGATT=0
  • Expected Response: OK
  • Then retry: AT+CGACT=0,1

Step 9: Turn On GPS Module

AT+QGPS=1,1,0,1
  • Parameters:
    • 1 = Mode: Stand-alone
    • 1 = Accuracy: Low (faster fix, recommended for challenging conditions)
    • 0 = Fix count: Continuous positioning
    • 1 = Fix rate: 1 second intervals
  • Expected Response: OK
  • CRITICAL: After this command, state should change from 3 (WWAN loaded) to 4 (GNSS loaded)

Step 10: Verify State Changed to 4 (CRITICAL CHECK)

AT+QGPSCFG="priority"
  • Purpose: Verify state changed to 4 (GNSS loaded)
  • Expected Response: +QGPSCFG: "priority",0,4 (state 4 = GNSS loaded)
  • ISSUE: Sometimes returns +QGPSCFG: "priority",0,3 (state 3 = WWAN loaded) - GPS cannot work in this state!

Step 11: Check GPS Status

AT+QGPS?
  • Purpose: Verify GPS reports it is ON
  • Expected Response: +QGPS: 1 (GPS is ON)

Step 12: Check Satellite Visibility

AT+QGPSGNMEA="GSV"
  • Purpose: Get satellite visibility data (GSV = Satellites in View)
  • Expected Response: +QGPSGNMEA: $GPGSV,... (NMEA sentences) or OK (if no satellites found yet)

Step 13: Attempt to Get Location

AT+QGPSLOC=2
  • Purpose: Get GPS location (2 = format with date/time)
  • Expected Response:
    • +QGPSLOC: <lat>,<lon>,<alt>,<date>,<time>,<num_sat>,<hdop> (success)
    • +CME ERROR: 516 (No fix - GPS not fixed yet - this is normal, keep trying)

Step 14: Turn Off GPS

AT+QGPSEND
  • Purpose: Turn off GPS module
  • Expected Response: OK

Problem Description

Issue: After running AT+QGPS=1,1,0,1 and receiving OK, the state verification (AT+QGPSCFG="priority") sometimes shows state is still 3 (WWAN loaded) instead of 4 (GNSS loaded).

Expected Behavior:

  • State should change from 3 to 4 immediately after AT+QGPS=1,1,0,1 returns OK
  • GPS can only work when state is 4 (GNSS loaded)

Observed Behavior:

  • First test run: State correctly changed to 4 ✓
  • Second test run: State remained at 3 ✗ (GPS cannot work)

Additional Notes:

  • Priority mode is set correctly: AT+QGPSCFG="priority",0,1 returns OK
  • Priority mode query shows: +QGPSCFG: "priority",0,3 (priority_type = 0 is correct, but state is still 3)
  • AT+QGPS? returns +QGPS: 1 (GPS reports it is ON, but state is still 3)
  • PDP context is deactivated before GPS activation
  • No network registration is performed (GPS should work independently)

Questions for Quectel:

  1. Why would state remain at 3 after AT+QGPS=1,1,0,1 returns OK?
  2. Is there a delay required between setting priority mode and turning on GPS?
  3. Are there any prerequisites that must be met before state can change to 4?
  4. Could this be a firmware issue with BG95M3LAR02A03_BETA1110A?
  5. Is there a way to force the state to change to 4?

Complete Command Sequence (in order)

AT
AT+CPIN?
AT+CMEE=2
AT+QGPSCFG="priority",0,1
AT+QGPSCFG="priority"                    (verify)
AT+QGPSCFG="gnssconfig",1
AT+QGPSCFG="nmeasrc",1
AT+QGPSCFG="antennatype",1
AT+QGPSXTRA=1
AT+QGPSDEL=0
AT+QGPSEND
AT+CGACT?                                 (check PDP)
AT+CGACT=0,1                              (if PDP active)
AT+CGATT=0                                (if deactivation fails)
AT+CGACT=0,1                              (retry after detach)
AT+QGPS=1,1,0,1                           (turn on GPS)
AT+QGPSCFG="priority"                     (verify state = 4)
AT+QGPS?                                  (verify GPS is ON)
AT+QGPSGNMEA="GSV"                        (check satellites)
AT+QGPSLOC=2                              (get location - repeat until fix)
AT+QGPSEND                                (turn off GPS)
2

I was able to get the GPS functionality to work. It turns out I cannot get a signal inside of the building I am in.

3

Inside the room, the GPS signal will be greatly weakened and blocked. Your device needs to be placed outdoors or in an open area.

4

Herbert, do you see any areas where my logic can be refined?

5

I think your logic is reasonable.