I picked up an ultrasonic range finder and was hoping I could repurpose it for making a compressed air leak detector.
I did a simple sketch with Serial.println(pulseIn(pingPin, HIGH)); and blasted some compressed air at it, but the trace simply indicates “0” at the default 1 second interval.
I believe these ultrasonic sensor’s frequency response centers around 40kHz and I believe the turbulence from an air leak expresses itself in that range. If this had worked, I was going to make a band-pass filter and frequency divider to get an audible signal.
Should this work and I’m simply doing something wrong, -or- barking up the wrong tree?