Hi. I was having trouble with a Telit ME910C1-WW. I was unable to connect to the cellular network. I wondered if a firmware upgrade would help. I did that, and I see three serial ports in Linux, but I get no response on any of them.
In Windows i see one serial port, but I also get no response from it.
What should I do? Is it bricked? Is there any way to recover from this?
Please share the details of you host device(Raspberry Pi/PC).
Which tool are you using for the serial communication?
I would appreciate any logs or screenshots that you believe could provide a comprehensive understanding of the issue you are experiencing
Sure thing.
The ME910C1-WW is connected to a RPi 5 with the latest software. It’s sitting in the PCIe module hat.
$ cat /etc/os-release
PRETTY_NAME=“Debian GNU/Linux 12 (bookworm)”
NAME=“Debian GNU/Linux”
VERSION_ID=“12”
VERSION=“12 (bookworm)”
VERSION_CODENAME=bookworm
ID=debian
HOME_URL=“https://www.debian.org/”
SUPPORT_URL=“Debian -- User Support”
BUG_REPORT_URL=“https://bugs.debian.org/”
I can see the serial ports:
$ dmesg | grep tty
…
[ 713.635337] usb 3-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 713.635539] usb 3-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 713.635652] usb 3-1: GSM modem (1-port) converter now attached to ttyUSB2
, but when I connect with minicom, I get no response. not even an echo of the things I type. I can hit AT, then enter, and I should get an OK, but I get nothing. I don’t even see the characters AT showing.
$ minicom -b 115200 -D /dev/ttyUSB2
That did work before the firmware upgrade.
I had tried a lot of things, and the module was in a weird state. I was trying to get ECM working, and for whatever reason, the serial ports had disappeared. I was hoping a firmware upgrade would put it back to a default state. I’m not really sure how that happened.
When I connect the serial port on the hat to a windows machine, I see Telit Serial Diagnostics Interface (COM20) in the device manager. If I try to connect with PuTTY, I get nothing. I’m not using any flow control, just an 8N1 connection.
It’s kind of weird that Linux would see 3 com ports, and windows would only see one.
The firmware I used was the one here: Cellular Modems Technical Documents and Compliance
under the heading Telit ME910C1-WW Mini PCle LTE-M & NB-IoT Module
SKU: S135
Prior to the firmware upgrade, it looked like this:
AT#ECM=1,0
OK
AT#USBCFG?
#USBCFG: 3
OK
AT#ECM?
#ECM: 0,1
OK
AT+CPIN?
+CPIN: READY
OK
AT+CREG?
+CREG: 0,0
OK
AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“super”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 2,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 3,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 4,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 5,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 6,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
OK
AT+CSQhclient -v wwan0
+CSQ: 99,99
I did notice that now, since the firmware upgrade, I have an IP address for wwan0. In the Asset Manager I see the device status and cellular status as orange. I will investigate further… I didn’t have an IP address at first after the firmware upgrade.