Can't connect via ECM

alexanderabbott96 · January 18, 2024, 4:32pm

I just received my Sixfab 4G/LTE Cellular Modem Kit for Raspberry Pi, and I’m following along with the Getting Started with Base HAT + Telit Modules Guide.
The hardware setup went smoothly with my Raspberry Pi 4 B. Below are the commands and outputs from the end of the guide.

lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 006: ID 1bc7:1206 Telit Wireless Solutions LE910C4-NF
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

dmesg | grep ttyUSB
[ 9.637558] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB0
[ 9.660084] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB1
[ 9.671236] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB2
[ 9.674175] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB3
[ 9.684014] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB4

Next, I move on to the guide Cellular Internet Connection in ECM Mode.
I run the command lsusb -t and get the following:

lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 6, If 0, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 6, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 1: Dev 6, If 2, Class=Communications, Driver=cdc_ether, 480M
|__ Port 1: Dev 6, If 3, Class=CDC Data, Driver=cdc_ether, 480M
|__ Port 1: Dev 6, If 4, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 6, If 5, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 6, If 6, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 6, If 7, Class=Vendor Specific Class, Driver=option, 480M

Next starts the AT commands, and that’s where things begin to go wrong.
I ran sudo apt install python3-pip and it was already the newest version. So onto pip3 install atcom and it installed no problem. I went to test my connection with atcom AT and I receive [ERR] Couldn’t open serial communication. I have tried a fresh OS several times, I have removed and reseated the hat and card several time, and I’ve tried 3 different USB cables. I’m at a loss. Please help.

saeed · January 18, 2024, 9:12pm

Hello @alexanderabbott96,

I am assuming you have bookworm version(Debian 12) of the Raspberry Pi OS.
If yes it comes with modemmanager installed. The modemmanager blocks all the USB interfaces of the cellular module. You will need to remove it to access the USB interface. Use the following command to remove modemmanager.
sudo apt purge modemmanager

alexanderabbott96 · January 21, 2024, 2:13am

Thank you @saeed , I can now communicate over serial with atcom. Now when I send the command
atcom AT

I get the expected response of OK. When I went to the next step in the guide and send the command atcom AT+CGDCONT=1,"IPV4V6","super" I get the response ERROR. Is there a different guide I should be using to set this up?

saeed · January 22, 2024, 5:57am

The command should be atcom AT+CGDCONT=1,\"IPV4V6\",\"super\"
as mentioned in the README of the atcom repo or in the Sending AT Commands tutorial.