Ultrasonic Sensor on an Oscilloscope

So having an oscilloscope makes me always wonder how most electronics work and communicate data. I unfortunately am no expert but sometimes a scope can really help you better understand what's actually going on. In my testing of sensors for the sensor project, I was looking at the Ultrasonic sensors output. Really it's pretty straight forward.

The sensor puts out a pulse and listens back for the response. When that pulse is sent out, the output pin for the echo is set to HIGH. When the reflected ultrasonic sound comes back, the echo pin goes back down to LOW. So essentially all that an arduino does it measure the time between the high and low rise and fall, then calculate the distance based on the speed of sound.

Here was a short video of me moving back and forth in front of a sensor showing the incresing and decresing pulse length.