I just got a Huawei MSI2131 and am trying to use it (on an Intel Edison, Yocto distribution). The device shows up as 12d1:1506 Huawei ... E398 LET/UMTS/GSM Modem/Networkcard.
But there is no /dev/ttyACM0, nor is there /dev/ttyUSB0 to work with when I boot up with this device attached.
I tried the standard modeswitch command, but got this response: Error: can't use storage command in MessageContent with interface 0; interface class is 255, expected 8. Abort.
So then I tried just forcing the driver to deal with the Huawei in its original state,
echo 12d1 1506 > /sys/bus/usb/drivers/cdc_acm/new_id
This did create /dev/ttyACM0 and I could launch a PPP link on it. But there was also an information/warning message from the driver, something like
cdc_acm 1-1:1.1 This needs exactly 3 endpoints
(and indeed, I would have expected to see /dev/ttyACM0, /dev/ttyACM1, /dev/ttyACM2 but only got the first).
Is there something I am missing?