CatM+GNSS module : cellular and GNSS simultanous incompatible ?

[HappyUser]

What should have been an easy switch from the regualr sim7089 module to the CatM+GNSS module (also based on SIM7080), ended up in some serious back to basic debugging.
This link (https://github.com/wottreng/SIM7080G-NB-IoT-Cat-M-LTE-GPS), mentions:
GPS/GNSS and cellular can not be used together. Causes module to hang and be unresponsive

We are going to check whether that is the cause of our issue with this module.
Anyone else experience with this incompatibility.
Thanks

[felmue]

Hello @HappyUser

this seems to be true. In version 1.05 (but not in older versions) of the Hardware Design document section 4.3.2 GNSS Application Guide there is a note:

Due to the limitation by Qualcomm chipset, the LTE and GNSS RX chains of SIM7070x and SIM7080G share some hardware blocks, therefore concurrent WWAN and GNSS operations are not supported.

Thanks
Felix

[HappyUser]

@felmue Thanks,
And now i am really curious about the Ideas from the M5Stack engineers about a fast responding program that integrates MQTT and GNSS. We are also working on it now.

[HappyUser]

@HappyUser First tests seem to indication that in order to switch from data mode to GNSS mode, you need to power off the GNSS module. As a result, the GNSS forgets its position and it takes another 5 to 10 seconds to get updated position data again. Btw, during the whole operation the module is powered. we are open to smarter solutions for this problem.