About
In this bonus lesson, we use an ultrasonic sensor to measure distance. A sound wave pulse is directed at an object and the time it takes for the echo to return can be related to distance using the speed of sound. A user interface is built around the sensor to make a non-contact ruler which can measure over 10 feet. Units can be inches or centimeters. A momentary button is used to save data to a table for later use. This useful gizmo can be used whenever a physical ruler just can't be used or is impractical.
Price
Free