Ultrasonic Sonar Distance Sensor from Adafruit

Similar to dolphins’ echo-location ability, ultrasonic sensors are used to detect the distance between the object and the sensors. With this function, it is commonly used for automation, interactive art, and motion sensing.

Technical Description

A ultrasonic sensor consists of a transmitter and a receiver. The transmitters sends high-level signal at a certain frequency and the receiver detects whether there is a pulse signal back. The time duration from sending the signal to receiving it back multiplied by the sound speed can give us the distance between the sensor and the object being detected.

Limitation

Different devices may have distinct restrictions on the distance that can be measured with relatively high accuracy. Be careful when selecting a suitable one for you.

Skill

Rookie

Sample Sensors

Ultrasonic Distance Sensor: https://www.sparkfun.com/products/13959. 

Ultrasonic Sonar Distance Sensor: https://www.adafruit.com/product/3942.

Sample Exercise

https://www.instructables.com/id/Simple-Arduino-and-HC-SR04-Example/.