ULTRASONIC RANGE FINDER

Abstract

A range finder determines the range between the observer and the obstacle. The range finders employing infra-red and ultrasonic waves are highly popular. This particular ultrasonic rangefinder can measure distances up to 400 centimeters at an accuracy of 1 centimeter. ATmega16a microcontroller and the ultrasonic transducer module HC-SR04 forms the basis of this circuit. The ultrasonic module sends a signal to the object, then picks up its echo and outputs a wave form whose time period is proportional to the distance. The microcontroller accepts this signal, performs necessary processing and displays the corresponding distance on the 3 digit seven segment display. This circuit finds a lot of application in areas like automotive parking sensors, obstacle warning systems, terrain monitoring robots, industrial distance measurements etc.