The main body of the module consists of ESP32-WROVER-B and SIM800L modules. The TYPE-C interface is extended from the periphery using the USB-to-serial port chip CP210X. It can be directly connected to a computer with a USB cable for debugging. The data transmission is fast and stable. The ESP32-WROVER-B is a universal WI-FI+BT+BLE MCU module, integrating the ESP32-D0WD chip, PCB on-board antenna. SIM800L is a 4-band GSM/GPRS module with operating frequencies of 850/900/1800/1900MHZ, capable of transmitting low-power voice, SMS and data information. The most prominent feature of this module is that it integrates the ESP32-WROVER-B and SIM800L modules, combines the functions of the two modules, and is equipped with a lithium battery charging and discharging circuit. It can supply power to the battery and charge the battery, and has overcharge and overdischarge protection.