2.The ultrasonic distance measuring instrument of single chip microcomputer is designed with single chip microcomputer+-SR04 ultrasonic sensor+Nixie tube+button+buzzer. 1.Use high-quality materials. -SRO4 ultrasonic ranging module, stable measurement, range up to 4 meters. 3.The alarm distance can be set. After pressing the setting button, you can press the plus or minus keys to modify the alarm distance, and it has the function of saving after power failure. 4.When the measured distance is less than the set distance, the buzzer alarm. Can be used as a car reversing radar, and the alarm distance can be set by pressing a button. 5.The characteristics of this design: wide measurement range, stability, and very convenient operation. It can be used when powered on., Manufacturer: Akfldms