Using ppp0 to connect but AT communication not working

Hi, all
Actually, I do not know the practical operation principle of the “RASPBERRY PI 3G/4G&LTE BASE HAT”, i just connect this module with RASPBERRY PI, then follow the instruction of “Cellular Internet Connection in ECM Mode”. The connection is not stable, i need to wait a moment then it can connect the internet (actually, i do not know whether it is turely connect, i can using ppp0 to ping some website like google or sixfab, and the blue light on the module is flashing, but, I can’t communicate with the module via AT commands when the blue light is blinking). Has this happened to anyone?


Did you go through the troubleshooting guide:

Also, if you have followed the ECM tutorial without any problems, you should not use ppp0 interface but usb0 (for Quectel module) or wwan0 (for Telit module).