SIM820X RNDIS Dial-Up

Check whether SIM820X and Raspberry Pi and other devices are connected well through the following commands, if there is no problem, you can see Qualcomm devices and ttyUSB0-USB4

 lsusb
 ls /dev

After connecting the device, copy the following commands to the Terminal:

wget https://www.waveshare.com/w/upload/1/1e/SIM820X_RNDIS.zip
sudo apt-get install python3-pip
sudo pip3 install pyserial
sudo apt-get install unzip
unzip  SIM820X_RNDIS.zip
sudo chmod 777 SIM820X_RNDIS.py
sudo python3 SIM820X_RNDIS.py

After dialing, the Raspberry Pi can see that usb0 gets the ip through the following command:

ifconfig

Test usb0 networking status

 ping -I usb0 www.baidu.com

If you cannot get the IP or fail to connect to the Internet, use the following commands to get the IP and connect to the Internet:

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

If you need to switch to windows, or restore the default settings of the module, you can send the following command to restore through the serial port:

at+cusbcfg=usbid,1e0e,9001

SIM820X RNDIS Dial-Up

Raspberry Pi 400 GPIO Header Adapter, Header Expansion