What is an Ultra Sonic Sensor? - ECEdreamTeam/GroupProject GitHub Wiki

The HR-SR04 UltraSonic Sensor is a chip that can be interfaced with the microcontroller, Arduino Uno. The HR-SR04 can be sold for less than $3 because of the basic capabilities. The UltraSonic sensor is a sonar based and range finding chip. The chip contains a receiver and a transmitter which are easily located on the outside. The transmitter sends out 8 bursts of “pings” which are sent out and come back to the receiver. The receiver uses a timer and a clock cycle to determine how long the "ping" was sent out and returned back. The UltraSonic Sensor acts very similar to the way bats are able to move around. The sensor can very effective and pick up objects, movements, and noises regardless of excess sunlight or with black light.

The UltraSonic Sensor needs very little power supply to operate which is due to the limitations to the chip. The chip runs on 10mA and the limitations to the range of the ultrasonic sensor is from 2cm to 400cm. The other restriction to the ultrasonic range finder is the measuring angle. The "pings" that are sent out only have a measurable angle up to 15 degrees. This may not be the most efficient chip; however, it is very reliable. The ultrasonic sensor uses 4 pins which include a ground, power supply, trig pin (input), and echo pin(output).