NDIS dial-up and self-starting

Change to RNDIS(9001) mode

Use the following command to check whether SIM820X and Raspberry Pi and other devices are connected properly. If there is no problem, you can see Qualcomm (Qualcomm) devices and ttyUSB0-USB4.

lsusb
ls /dev

• After connecting the device, copy the following command to the Terminal.
• Send the following command via minicom, and wait for the module to restart.

AT+CUSBPIDSWITCH=9001,1,1

• If you use RM5XXX, please use this command

AT+QCFG="usbnet",0
AT+CFUN=1,1

NDIS Dial-up

sudo apt-get install p7zip-full
wget https://www.waveshare.net/w/upload/8/89/SIM8200_for_RPI.7z
7z x SIM8200_for_RPI.7z -r -o./SIM8200_for_RPI
sudo chmod 777 -R SIM8200_for_RPI
cd SIM8200_for_RPI/Goonline
make
sudo ./simcom-cm &
sudo apt-get install udhcpc
sudo udhcpc -i wwan0
sudo route add -net 0.0.0.0 wwan0

You can successfully see that DNS has been generated at the bottom

Auto-start at boot

Set boot up, open the Raspberry Pi boot configuration script

sudo nano /etc/rc.local

Add the startup command to the penultimate line, note that it is the absolute path of your running Internet file, that is, the previous line of exit 0.

sudo /home/pi/SIM8200_for_RPI/Goonline/simcom-cm &
sudo udhcpc -i wwan0

Note that you must add "&" to run in the background, otherwise the system may not be able to start.