Killed my AT Terminal

[jsnawrocki]

Hey all,

I am at my wits' end.
I was changing my modem composition in an attempt to get a Verizon Data line sim working.
Apparently, AT+QCFG="usbnet",0 is the default QMI.
AT+QCFG="usbnet",2 is MBIM.

I was following a thread here that said "Clear out your APNs again, delete your APN under ModemConnection Profile, and try AT+QCFG=”usbnet”,1 (ECM mode) for giggles. Then power cycle the router and then enter the APN into connection profile again then power cycle again."

Well, I guess that 1 value has scrambled my ttyldev port, so my AT command terminal just won't work now.
I have putty, have tried various commands, but absolutely cannot get my terminal port fixed.

Can anyone help?
It's a Quectel RM500q-GL in a Wodaplug LTE H721 router.
It's running the OpenWRT firmware which hasn't been messed with.

[Didneywhorl]

It's not borked, no worries.

The WebUI stuff doesn't seem to like ECM mode on the modems.

Remote in via SSH and send AT commands with picocom or microcom.

[jsnawrocki]

Hey friend, thanks for the reply.

Could you dial your answer back to noob-mode for me?
I seem like I know what I'm doing, but I really don't, lol.

I have only managed to get in via putty, which is the only quick and free ssh I've found.
What is picocom and microcom?

[Didneywhorl]

no worries.

picocom and microcom are SSH/serial console applications that have to be present on the router. Usually microcom is already on rooter/goldenorb images.

if you SSH into the router, and login using your root name and admin password you can see which is available by just sending "picocom" or "microcom" and seeing it it returns either command not found or asks for more for the command.

Then just google for ye olde AT commands over microcom or picocom.

I don't have a ready tutorial or links myself.

[jsnawrocki]

Ok I've logged in via Putty and tried picocom and microcom - here is what comes back:

login as: root
root@192.168.1.1's password:


BusyBox v1.28.3 () built-in shell (ash)

_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
-----------------------------------------------------
OpenWrt 18.06.0, r7188-b0b5c64c22
-----------------------------------------------------
root@PandaRooter:~# picocom
No port given
root@PandaRooter:~# microcom
-ash: microcom: not found
root@PandaRooter:~#

I'm not sure what No Port Given means, but it seems this router has picocom?

[jsnawrocki]

Another update - I log in via Putty, and i run the command:


root@PandaRooter:~# picocom /dev/ttyUSB0
picocom v1.7

port is : /dev/ttyUSB0
flowcontrol : none
baudrate is : 9600
parity is : none
databits are : 8
escape is : C-a
local echo is : no
noinit is : no
noreset is : no
nolock is : no
send_cmd is : sz -vv
receive_cmd is : rz -vv
imap is :
omap is :
emap is : crcrlf,delbs,

Terminal ready

I feel like this should e be it...but it's just frozen. I can't type or enter any commands. I can hit CNTL-A CNTL-X to exit picocom and go back to the command prompt. Any idea why Terminal Ready is just frozen?

Edit: C-a followed by C-c enables local echo, which lets me see anything I enter. I'm getting closer, but can't seem to enter AT+QCFG="usbnet",0 and get it to do anything. The enter key just moves the cursor down like a carriage reset, but the command doesn't actually take.

[Didneywhorl]

Try ttyUSB3 or ttyUSB2

[jsnawrocki]

We freakin' did it!

ttyUSB3 was the answer. The stupid part is, I actually tried USB0, 1, and 2 (because those are the only ones I've seen in the AT commands so far...).
When 1 and 2 just returned errors, I went back to 0.

So in the end:
Putty, SSH to router IP
Log in with admin credentials
picocom /dev/ttyUSB3 (also learned that this is case sensitive!)
Terminal Ready
AT+QCFG="usbnet",0
ok

Reboot router.
Now I can web in again and comm port is showing dev/ttyUSB again!

Thanks friend! So many thanks.

[Didneywhorl]

Sweet! <HighFive>