It is well know that pests like rats, mice etc are repelled by ultrasonic frequency in the range of 30 kHz to 50 kHz. Human beings can’t hear these high-frequency sounds. Unfortunately, all pests do not react at the same ultrasonic frequency. While some pests get repelled at 35 kHz, some others get repelled at [...]
It works on the sonar principle, sending an ultrasound burst and listening for first echo. The burst generated by the oscillator built around U4D (you must set the frequency using TR2 to have 40 kHz or the maximum sensitivity), U4E buffers the output and U4F boost the signal doubling the voltage span across the TX [...]
This circuit is measuring the range to an object by using ultrasonic transmitter and ultrasonic receiver. The distance is calculated by PIC microprocessor and is displayed on the three digit 7-segment LED display.
Related Links
More circuit about Meter
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More about PIC Microcontroller
More circuit about ultrasonic
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