How to use GSM module to receive short messages, and then control relays through single chip microcomputer to complete the switch control of electrical appliances?

The GSM module is actually very easy to control. Basically, the reserved control ports of GSM module are all serial ports except the power control line, and they are all operated by their corresponding AT commands. You only need to initialize the GSM module through the serial port of the single chip microcomputer. After receiving the short message, it can trigger the serial port interruption of single chip microcomputer to receive data, and then the program turns to control relay or switch tube to realize the control of electrical appliances.