Executing AT Commands on USB Modem
 

I have a USB modem on a Debian install that I want to be able to use AT commands to diagnose, specifically for obtaining signal strength (RSSI). I know the command for this is AT+CSQ but I cannot seem to get the interface for issuing AT commands to work.

The modem is using /dev/ttyACM0 and when I try to use minicom, I type in AT commands and nothing is echoed to the screen (Yes, echo is turned on). Maybe I just don't know how to use minicom correctly.

Any assitance is appreciated.

I will guess you need to start with modemtool since com1 isn't how the modem is connected.

Is minicom configured to use /dev/ttyACM0?
Are all the settings correct i.e. baud rate, start,stop bits, parity etc?

Yes, except I get the indication that the modem is setup with a speed of 921200 which isn't an option in the minicom config. Can this be set somewhere else?

What is the make/model of your USB MODEM and post the output of the lsusb command.

The modem is a Pantech UMW190 like this one.

http://www.phonenews.com/verizon-lau...al-modem-8868/

lsusb results in the following output:

Bus 002 Device 003: ID 106c:3716 Curitel Communications, Inc.
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000

I found some info that should help you get going. According to the following the baudrate 460800.
http://ubuntu-ky.ubuntuforums.org/sh....php?p=8820174

Thanks but the modem is working. What I need is a way to access the AT command interface to the modem, specifically to periodically obtain the received signal strength. BTW, I am using Debian on an embedded device so there is no desktop--only command line.

Try minicom again using a baudrate of 460800.

I finally did get it working in minicom with a baud rate of 921600. The issue was that the modem will not repond to AT inquiries while it's actually connected. I guess I should have figured that out sooner.

I'd still like to be able monitor the signal strength (using the AT command AT+CSQ) while the modem is connected. Does anyone know if this is possible?