4G/5G

This section introduces how to use the M.2 B KEY interface functions on the Raspberry Pi, laying the foundation for subsequent project development.

danger

• The test uses the SIM7600. If using other modules, refer to the corresponding 4G/5G module's Wiki.
• The board itself does not support 4G/5G; the module must be connected via the M.2 B KEY interface. The M.2 B KEY interface provides only a USB2.0 channel and does not support PCIe devices.

warning

• To turn off the 4G/5G module, use GPIO6 (BCM pin 6). Output high to disable the module, output low to enable it.
• Enabling or disabling the module takes some time (approximately 30 seconds).

Troubleshooting

No new ttyUSB device appears

• Execute the following commands in the terminal to load the USB device descriptors:

  sudo modprobe option
  sudo sh -c 'echo "1e0e 9011" > /sys/bus/usb-serial/drivers/option1/new_id'
  sudo sh -c 'echo "1e0e 9018" > /sys/bus/usb-serial/drivers/option1/new_id'
  sudo sh -c 'echo "1e0e 901E" > /sys/bus/usb-serial/drivers/option1/new_id'

Setting up the AT command configuration environment

• Install the text-based serial communication tool minicom:

  sudo apt-get install minicom 

• Connect to the 4G/5G module port (use ttyUSB2, which appears when the module is connected; adjust the port according to your actual situation):

  sudo minicom -D /dev/ttyUSB2 

• The following AT commands are common to both 4G and 5G modules:

  Command	Description	Return Value
  AT	Test command	OK
  ATE	ATE1 enables echo ATE0 disables echo	OK
  AT+CGMI	Query module manufacturer	OK
  AT+CGMM	Query module model	OK
  AT+CGSN	Query product serial number	OK
  AT+CSUB	Query module version and chip	OK
  AT+CGMR	Query firmware version serial number	OK
  AT+IPREX	Set module hardware serial port baud rate +IPREX:	OK
  AT+CRESET	Reset module	OK
  AT+CSQ	Query network signal quality; returns signal value +CSQ: 17,99	OK
  AT+CPIN?	Query SIM card status; returns READY if the SIM card is recognized properly	+CPIN: READY
  AT+COPS?	Query current operator; returns operator information when connected to the network +COPS:	OK
  AT+CREG?	Query network registration status +CREG:	OK
  AT+CPSI?	Query UE system information
  AT+CNMP	Network mode selection command: 2: Automatic 13: GSM only 38: LTE only 48: Any modes but LTE ... ....	OK

  • For more AT commands, refer to: SIM7600 AT Command Reference
  • For more documentation, refer to: SIM7600 Reference

ifconfig cannot find the device

• Click here to set up the AT command configuration environment
• Compare the newly added ttyUSB interfaces (if the new interfaces are ttyUSB0~ttyUSB4). If no new ttyUSB device appears, click here to configure.
• Use the newly added ttyUSB interface for configuration changes (here we use the newly added ttyUSB2):

  sudo minicom -D /dev/ttyUSB2 

• Enter the following command and press Enter; the module will automatically restart to apply the settings (adjust according to the actual module requirements – each module supports different dial‑up methods; the following uses Qualcomm's RNDIS dial‑up).
• This command needs to be set only once; the module will default to this mode on subsequent power‑ups.

  AT+CUSBCFG=USBID,1E0E,9011  # 1E0E: Vendor ID    9011: according to the actual module requirements

  
• Rescan the devices:

  ifconfig 

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4G/5G Usage

• Connect the 4G/5G module and the SIM card to the device, then power on.
• Use ifconfig to scan for usb0 (USB network adapter – the exact device name may vary; it is not necessarily usb0). If ifconfig does not find the device, click here to troubleshoot.

  ifconfig 

  
• If the SIM card is properly connected, the NET LED blinks normally but no IP address is obtained, verify that the SIM card is working.
• If the SIM card is working but still no IP address is obtained, execute the following commands in the terminal to renew the IP address:

  sudo dhclient -v usb0
  sudo apt-get install udhcpc
  sudo udhcpc -i usb0
  sudo route add -net 0.0.0.0 usb0

• Test whether the wireless network card can ping Baidu successfully; be sure to connect the antenna.

  ping -I usb0 www.baidu.com  # Here the port added by the 4G/5G module is usb0; adjust the command according to your actual situation

• If you are using an IoT SIM card that successfully registers on the network but dial‑up fails and ping does not work, try one of the following AT commands to select the optimal frequency band (click here to set up the AT command configuration environment):

  AT+CNBP=0x0002000000400183,0x000001E000000000,0x0000000000000021
  AT+CNBP=0x0002000000400180,0x480000000000000000000000000000000000000000000042000001E200000095,0x0000000000000021

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