I want to use a serial Modem like Huawei E303
or Huawei MS2372 for my project.
And I want to use SIM cards from a special M2M provider.
Now I already got the setup working on a normal RaspberryPi with Raspbian Stretch and NetworkManager and ModemManager installed.
When I try the exact same hardware and exact same configuration files with NetworkManager and ModemManager on ResinOS, the ModemManager goes into a loop and never finishes the connection.
I think part of the reason might be that my (working) configuration file in /etc/NetworkManager/system-connections/my-m2m-conf specifies an EMTPY apn field. This is accepted and used successfully by the ModemManager on Stretch and is not used for some reason by the ModemManager on resinOS (it just tries a default APN instead - without success, as you can see in the logs).
Does Resin have special requirements for the config files that other systems do not?
Attached, you will find a log of ModemManager --debug on both systems.
They are regular M2M SIM cards from the German carrier Telekom.
The configuration from my post worked with ModemManager on Raspbian and on Ubuntu 16.10 out of the box.
Is this device using the OS image you downloaded from the resin.io dashboard? If so, could you send us the dahsboard lnk to the device so we can take a look at it?
Hi Floion,
The problem seems to be unique to the specific installation on the RaspberryPi, since the problem was not reproducible with 6 different installations.
If you are still interested to look for the problem with the support help, i’ll notify you via PM as soon as we have the system running for you to work at.
Hi @floion,
I was finally able to reproduce the error. The ModemManager is unable to connect, due to not releasing the device lock on Port tty/USB2
Even after disconnection the device, the Port is still on lockdown
Closing the ModemManager also leaves the device lock unhandled.