This design adopts the hardware circuit and software design of low-cost, high-precision, miniaturized digital ultrasonic rangefinder with single chip microcomputer as the core. After the system is started, the ultrasonic wave emitted by an ultrasonic transmitter is transmitted in the air for a period of time and then reflected back before the detected object, and the signal is amplified and shaped by the ultrasonic receiver, the ultrasonic receiver circuit and the receiver chip. After receiving the echo, the ultrasonic receiver circuit sends a falling level to enter the interruption program. In the interruption program, the temperature detection circuit of the single chip microcomputer converts the read value into the current temperature speed, and the detection distance is calculated by using the time difference method. Finally, all the data are displayed in the LCD display circuit. This design adopts modular design, and the hardware includes microcontroller module, temperature compensation module, ultrasonic receiving module and liquid crystal display module. In the software design, the ultrasonic ranging program module, the display module, the temperature measuring program module and the external interrupt module are organically combined through the general program. The probe signal is comprehensively analyzed and processed by single chip microcomputer to realize various functions of ultrasonic range finder. Based on the overall design of the system, it is composed of hardware and software of each functional module. The relevant part is attached with hardware circuit diagram and program flow chart.
Experiments show that the system has reasonable hardware and software design, strong anti-interference ability and good real-time performance. After the system is expanded and upgraded, it can effectively solve the problem of automobile reversing.