DW5811c No com ports

[bkcberry]

Hey guys, i just got a batch of DW5811c/EM7455 modems from ebay and i cannot get com ports enabled on any of them. When i plug them up lsusb shows:

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Bus 001 Device 008: ID 413c:81c2 Dell Computer Corp. 4-Port USB 2.0 Hub

and cdc-wdm1 appears in /dev

I found instructions at the link below for enabling the com ports, but it says that it is already set to usbcomp=8.
https://zukota.com/sierra-wireless-em74 ... com-ports/

I hooked one of them up to a windows machine and used the sierra wireless utility to update the firmware to the latest generic version but that did nothing. Also danielwood's script does nothing because there are no com ports. Anyone have any ideas?

[Didneywhorl]

When hooked to linux, have you tried using microcom to send at commands?

[bkcberry]

I tried the command below, but it just output little characters with question marks. Wasn't sure if maybe I had the wrong port speed?

Minicom -D /dev/cdc-wdm1

Someone suggested that I try huweai terminal on windows, but I can't find any drivers that will install. The Dell drivers say something like they're not for my machine model and the Sierra wireless drivers don't work either

[bkcberry]

I figured it out!!

The com ports are enabled, ubuntu just wasn't loading a driver for them. I was able to get them loaded using these commands (as root):

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modprobe option
echo 413c 81c2 > /sys/bus/usb-serial/drivers/option1/new_id 

413c 81c2 are the values listed for the modem from the lsusb output. After running that i was able to use minicom ( minicom -D /dev/ttyUSB2 ) and follow instructions on the danielwood github page for converting the modem to a generic sierra wireless EM7455.

[Didneywhorl]

Good work!

[Didneywhorl]

I usually use the minicom -s command to setup my connection