Ultrasonic ranging method is rapid, convenient, simple, easy to achieve real-time control, mentioned the ultrasonic distance measurement system based on MCU design can be more in-depth understanding of SCM application.

This design uses a microcontroller as the core of low cost, high precision, miniaturization digital display ultrasonic rangefinder hardware circuit and software design. After starting the system, an ultrasonic emission head emission of ultrasonic transmission in the air after a period of time in front of the objects to be detected by the reflected back by the ultrasonic receiving head, ultrasonic receiving circuit, the receiving chip for signal amplification shaping, ultrasonic receiving circuit receives the echo after sending a drop level to enter the interrupt program, in the interrupt program SCM temperature detection circuit, from reading the numerical and converting the current temperature velocity, using the time difference method to calculate the detection distance, finally all the data in the LCD display circuit displays. The design uses the modular design, the hardware, including the microcontroller module, temperature compensation module, ultrasonic receiving module, LCD module. In software design, through the general program will ultrasonic ranging program module, display module, temperature measurement program module, external interrupt module organically unifies in together. The probe signal by single chip integrated analysis and processing, to achieve various functions of ultrasonic ranger. On the basis of the overall system design, hardware and software by the end of each function module. Relevant portion enclosing the hardware circuit diagram, program flow chart.

Proved by experiment, the system hardware and software design is reasonable, strong anti-interference ability, good real-time, after the system expansion and upgrade, can effectively solve the problem of car reversing.