Title Ultrasonic Level Sensor Based on MCS—51 _ ——The Hardware Design
Abstract This design is familiar with the SCM, Ultrasonic and LED and AD694 properties. With AT89C51, ultrasonic transducer using the piezoelectric level for automatic detection; LED real-time display measurement data; Convenient operation personnel testing results of monitoring system. The system hardware circuit design includes ultrasound circuit, receiving circuit, analog signal output circuit, digital tube display circuit, etc. Ultrasound circuit using NE555 firing pulse after two levels of power amplifier and pulse transformer transducer presser inspire piezoelectric element of producing ultrasonic signal. Receiving circuit altogether consists of three parts: The first part is isolating circuit; The second part is the signal amplifier circuit; The third part is the threshold circuit; AT89C51 is whole ultrasonic level sensor measuring system, the core part, Main task is to produce pulse signal circuit driver, through the launch ultrasonic transducer, and receives the ultrasonic issued ultrasonic produced along the signal drop back, triggering interrupts.