Waveshare SIM7600 Series - Receiving SMS Messages; SIM7600 CE-HAT SMS Test; Send Test SMS to Dongle; Serial Port Message Output

Receive Message
1.
Send a message from phone to the SIM7600 DONGLE: “This is a receive test for
SIM7600X！”
2.
The serial port will print data when receiving, for example: “SM”， 20， it means
that there are 20 messages in SM and the last message received is the 20th
message.
3. Read message：AT+CMGR=20 Read the 20th message 读（AT+CMGL="ALL" to read
all messages）
4. Delete message：AT+CMGD=20
5. Convert the message to string by convertor.。