Description
This is an ultrasonic sound based non-contact range finder. The device send sonar burst of ultrasonic sound waves from the transmitter end, ultrasonic sound is sound waves of frequency more than 20 KHz (not audible to human ears). Dolphins and bats use this principle to detect obstacle in front of them. The receiver end of the sensor detects received deflected sound signal from any obstacle or wall, in this way one can use the time taken by the sensor in sending and receiving the sound signals for the calculation of the distance of the wall or obstacle from the sensor. The sensor has 4 pins to be used with any microcontroller board. The pin descriptions are as follows: Trigger, Echo, Vcc, Gnd. The sensor works at DC 5 volt and when a pulse of few microseconds are send to the trigger pin, the sensor sends burst of eight cycles of 40KHz ultrasonic sound waves. The sensor can detect object as close as 2 cm and maximum upto 400 cm. The accuracy of the sensor could be as possible as 3mm.