Reed Switch Sensor Module for harduino

The HC–SR04 ultrasonic sensor uses sonar to determine distance to an object like bats do. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package. From 2 cm to 400 cm or 1” to 13 feet. Ultrasonic sensors are used typically in applications to measure the level or the distance. Especially in the level measurement ultrasonic sensors are used because they are quick and easy to implement.