Hands-On Robotics Programming with C++

How an ultrasonic sensor measures distances

Now that we've understood the basic workings of an ultrasonic sensor, let's think about exactly how the ultrasonic sensor measures distance:

In order to measure distance, the ultrasonic sensor generates an ultrasonic pulse. To generate this ultrasonic pulse, the trigger pin is set in a high state for 10 microseconds. This produces an eight-cycle sonic burst that travels at the speed of sound, which is received by the echo pin after colliding with an object. When this eight-cycle sonic burst is received, the echo will become high and it will remain high for a time duration that is proportional to ...