Hello, my name is Cyril HAENEL, and I am new on this
mailing list :)
I subscribed to this list because I was looking for
informations on Quectel LTE modem, and yesterday I found
this fantastic video :
https://media.ccc.de/v/33c3-8151-dissecting_modern_3g_4g_cellular_modems#t=690
I actually work on the Quectel LTE SC20 Smart module, which
is proposed with Android, but also Linux without all Android
layers.
We want to use the Linux version and we use the official
Quectel Linux SDK, based on Yocto.
We can successfully build and flash the image in the module,
no problem from this side.
But the goal of this module is not to be used just as an LTE
modem for an external host, it's a standalone module and we
embed our IoT application inside.
The problem we are facing is that we don't know how to start
a broadband connection !! There is absolutely no Quectel
documentation about that, and their support is really bad,
they don't help us at all...
So we done some reverse engineering to understand how the
internal Modem is connected to main processor, how to send
him AT command, how to start data connection, etc...
We finally found and understood all methods they use (Shared
Memory Devices, qmuxd, qmi proxy, QMI protocol, etc.....).
But we are stuck to the same point, we don't find any easy
way with scripts or some utilities with config file (to set
the APN for example) to start a broadband connection :(
We flashed an Android version in the SC20 to see how it
works, and they have Android applications which connect to
netmgrd, qmuxd, etc....
But we don't have these tools under Yocto Linux, so we
wondering how we can easily set our broadband connection.
Any help or comment will be great :)
Best regards,
Cyril
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Cyril Haenel
Registered Linux User #332632
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