GY-53L1 is a low-cost digital infrared ranging sensor module. Working voltage 3-5v, low power consumption, small size, easy installation. Its working principle is that the infrared LED emits light, after irradiating the measured object, the return light is received by the MCU, and the MCU calculates the time difference to obtain the distance. Direct output distance value. This module has two ways to read data, namely serial port UART(TTL level) PWM (switching value) or chip IIC mode. The baud rate of serial port is 9600bps and 115200bps, which can be configured and has two ways of continuous inquiry and output. It can save the setting when power is lost. Provide arduino, stm32 microcontroller communication program. Schematic diagram and internal MCU source code are not provided. In addition, the module can set a separate sensor chip working mode. As a simple sensor module, MCU does not participate in data processing. The module has added a switch output mode. After the upper computer is used to set the warning distance, the test distance is lower than the set value and the pin outputs a low level.