Trouble with SIM card when Fibocom FM101 and miniPCIe Adapter on Raspberry PI 4G/LTE Hat


I’ve been trying to use the Raspberry Pi Hat with a M2 modem that I have but I have some trouble getting it to recognize the SIM card that is inserted on the HAT.
AT Commands work well but as soon as I try to ping the SIM (using AT+CPIN?), I get an error “SIM not inserted”.
I reckon this might have to do with the pretty atypical setup that I used to try this out (M2 modem → miniPCIe Adapter → Sixfab HAT) but this still is strange to me since the pinout of the adapter should be alright, and I can ping and see every info about the modem so most of it seems to work.

Here a picture of the setup :

And the output from the AT commands :

For the full setup : RPi 4 on Bullseye, Fibocom FM101-EAU modem (QMI-enabled) (also tried with Intel-based Fibcom L850-GL), Sixfab Raspberry PI LTE Hat.

Thank you for any info that you have.


Compare the pins of the module and adapter you are using with the pins connected to the Base HAT.


Thank you for your input!
Effectively, I think there is a problem with the pinout. I haven’t been able to find the information for the adapter but that most likely seems to be the issue.
I will try finding a supported miniPCIe device that could work with the HAT. Thanks!