I am reaching out to seek assistance regarding an issue I am experiencing with GPS tracking on my B524 SoM mounted on an M.2 Evaluation Board. Despite multiple attempts to configure the device, I have been unable to send GPS location data to the Particle Console successfully.
Device Information:
• Model: B524 SoM
• Setup: M.2 Evaluation Board
• Firmware: Latest Device OS (v6.1.1)
Issue Description:
1. I have followed the official documentation to set up the device, including connecting the GNSS antenna to the appropriate port.
2. I have tried using both custom firmware and AT commands to enable and query GPS data (e.g., AT+QGPS=1 to enable GNSS and AT+QGPSLOC? to retrieve GPS data).
3. My firmware compiles and flashes successfully, but I do not receive valid GPS responses. I only get empty or error responses in the Serial Monitor logs.
4. I have tested various configurations, including enabling GNSS with different initialization commands, but the GPS does not provide a location fix or any valid data.
Debugging Attempts:
• Used the Cellular.command API with a callback to debug AT command responses.
• Confirmed that the GNSS antenna is properly connected to the CELL port.
• Verified cellular connectivity, which is working fine for non-GPS operations.
• Monitored logs using Visual Studio Code and Particle Serial Monitor, which consistently show empty GPS responses or no data.
Questions:
1. Is there a specific configuration required to enable and retrieve GPS data on the B524 SoM?
2. Are there any known compatibility issues with the M.2 Evaluation Board or GNSS antennas?
3. Could you provide additional debugging steps or sample firmware for enabling GPS on the B524?
4. Are there diagnostic tools or commands to verify the GNSS module functionality?
I would appreciate your guidance in troubleshooting this issue. Please let me know if you require additional details or logs to assist in resolving this matter.
The B524 has the Quectel EG91-E cellular modem, which does not support GNSS. The U.FL connector in that location is LTE Cat 1 cellular diversity, not GNSS.
The M524 has a EG91-EX, which does support GNSS, though the particle-som-gnss library only works with the M504 (BG95-S5). It does not currently work with the EG91-EX.
Thank you for the clarification.
Given that the B524 does not support GNSS and the M524 supports GNSS but is not currently compatible with the particle-som-gnss library, would it be better to switch to the M504 (BG95-S5) for seamless GNSS tracking integration?
Specifically:
1.Would the M504 (BG95-S5) work out-of-the-box with the particle-som-gnss library for GPS tracking?
2.Are there any significant trade-offs between the M524 and M504 in terms of cellular performance, coverage, or power consumption?
3.If I decide to stay with the M524, is there an alternative way to retrieve GNSS data via AT commands or another method?
4.Is there any planned support update for M524 GNSS in the Particle library?
I want to make sure I choose the best module for reliable GPS tracking. Thank you!
The M504 is only recommended for use in the United States, Canada, and Mexico. It uses LTE Cat M1 only, which is not widely supported outside this region.
The M524 supports Europe, Middle East, Africa, and some Asian countries, using LTE Cat 1, 3G, or 2G. It does not work in North America.
In theory it should be a relatively minor modification to make the particle-som-gnss library work with the EG91-EX, it just hasn't been done.
Thank you for the clarification. Since I am based in Europe, I understand that the M524 is the better option due to its support for LTE Cat 1, 3G, and 2G. However, as the particle-som-gnss library does not currently support the EG91-EX GNSS module, I have a few follow-up questions:
1.Is there a timeline for adding support for GNSS on the EG91-EX in the particle-som-gnss library?
2.In the meantime, could you provide guidance or examples on how to use AT commands with the EG91-EX to retrieve GNSS data?
3.Are there any recommended workarounds for integrating GNSS functionality while library support is pending?
I’d appreciate your advice on how best to proceed. Thank you!
There is currently no schedule for implementation of library support for the EG91-EX. However, it should just be a matter of looking at the Quectel EG91 GNSS manual and making any changes from how it's currently being done with the BG95. The process should be similar, but there may be minor differences in the actual AT commands or settings.