SIM7600G-H-M2 4G Communication Module linux Tutorials

hardware

• LattePanda 3 Delta 864 - Pocket-sized Windows/LattePanda Sigma - x86 Windows ×1
• SIM7600G-H-M2 4G Communication Module ×1
• 600-6000MHz 5G Antenna ×1
• Mouse / Keyboard
• SIM card with data plan

sofetware

• linux_driver.rar
• • Refer to the LattePanda tutorial (linux section) for OS installation

Installation Diagram

Note: The Sigma board is used here as an example. After installation, simply power on and boot.

Driver Installation and Device Recognition

When running a modern Linux distribution (e.g., Ubuntu 20.04/22.04/24.04) on the LattePanda Sigma, the kernel will automatically load the drivers. If drivers are not loaded automatically, please install them manually according to the driver manual.

• Check USB devices

command: lsusb

Look for a device with ID 1e0e:9001 (QMI mode) or ID 1e0e:9011 (RNDIS mode). The vendor name is usually displayed as SimTech or Qualcomm.

• Check communication ports

command: ls /dev/ttyUSB*

Expected result: You should see multiple ports, such as /dev/ttyUSB0 through /dev/ttyUSB4. Typically, ttyUSB2 or ttyUSB3 is the AT command port, while ttyUSB0 is usually the diagnostic port.

• Check network interfaces

command: ip addr

Expected result: You should see a network interface named wwan0, usb0, or cdc-wdm0 (its status may be DOWN).

If no /dev/ttyUSB* devices are found, the option driver may not have loaded automatically. Try loading it manually:

command: sudo modprobe option
command: sudo sh -c 'echo 1e0e 9001 > /sys/bus/usb-serial/drivers/option1/new_id'

Network Configuration

1. Using NetworkManager (Recommended for Ubuntu Desktop/Server)

• Ensure ModemManager is installed. If not, an active network connection is required for installation.

command: sudo apt update
command: sudo apt install modemmanager libqmi-utils

• Check modem status

command: mmcli -L

# Create a new 4G connection profile
# con-name: connection name (arbitrary, e.g., my-4g)
# ifname: leave empty or use * (let the system auto-detect the modem)
# apn: your carrier's APN
sudo nmcli connection add type gsm con-name "my-4g" ifname "*" apn "cmnet"

# Bring up the connection
sudo nmcli connection up "my-4g"

• Verify

command: ping www.google.com

2. Switching NIC Mode via AT Commands (RNDIS Driver-Free Mode)

• Install a serial port tool
  If not already installed, an active network connection is required for installation.

command: sudo apt install minicom

• Open the serial port to send commands

command: sudo minicom -D /dev/ttyUSB2 ## Typically, the AT command port is USB2; if it doesn't work, try other ports

• Send the mode-switching command

command: AT+CUSBPIDSWITCH=9011,1,1 9011 represents RNDIS mode

• Verify the network
  After the module restarts, run ip addr. You should see a NIC named usb0 or enx....... that has already been assigned an IP address (e.g., 192.168.x.x). At this point, internet access should work immediately.
  Note: To switch back from RNDIS mode to the default mode, send AT+CUSBPIDSWITCH=9001,1,1.

command: ping www.google.com

Common AT Command Operations

To debug the module under Linux, you can use echo and cat directly, or use minicom / socat.

#!/bin/bash
PORT="/dev/ttyUSB2" # Modify the port according to your actual setup

echo "Checking SIM status..."
sudo chat -V -s '' 'AT+CPIN?' OK > $PORT < $PORT

echo "Checking Signal Quality..."
sudo chat -V -s '' 'AT+CSQ' OK > $PORT < $PORT

Common Troubleshooting

1. System does not recognize /dev/ttyUSB* devices
   Cause: Ubuntu's brltty (Braille display service) often occupies USB-to-serial devices, causing conflicts.
   Solution:
   command1: sudo systemctl stop brltty-udev.service
   command2: sudo systemctl disable brltty-udev.service
   command3: sudo apt remove brltty
   Unplug and replug the module, or restart the computer

2. NetworkManager shows "Connected" but cannot access the internet
   Cause: This may be a DNS resolution issue or a routing priority issue (when both WiFi and 4G are active simultaneously).

Solution: Check the routing table: ip route. Make sure the default route (default via) points to the 4G NIC interface. Disconnect WiFi and Ethernet to test: sudo nmcli radio wifi off.

3. APN settings invalid / Dial-up fails
   Manually specify the APN via AT commands: Stop ModemManager first, then enter the serial port and input:

command1: AT+CGDCONT=1,"IP","your_APN"
command2: AT$QCRMCALL=1,1