WHAT IS ULTRASONIC SENSOR?
The ultrasonic sensor is a device that measures distances without any contact which means it can measure the distance between the object and itself without any contact. It works based on ultrasonic sound waves. It measures the distance by using ultrasonic sound waves.
PRINCIPLE OF ULTRASONIC SENSOR
The working of the ultrasonic sensor is mainly based on the ultrasonic sound waves. These sound waves are not hearable to the human ears. There are two parts of the ultrasonic sensor they are:
# transmitter
# receiver
The transmitter sends the ultrasonic sound waves above the 20khz which are not hearable to the human ear and the sound waves travel in the air in case the waves strike any object then the sound waves are reflected back and the waves are received by the receiver. Depending on the how much time the wave travels in the air the sensor can measure the distance of the object.
PHYSICAL OVERVIEW OF THE HC-SR04
The ultrasonic sensor has two cylindrical shapes as shown in the figure
one is the transmitter and another one is the receiver. The transmitter releases the sound waves above the 20khz frequency and the sound waves are received by the receiver after the waves bounce back by hitting the object.
crystal oscillator is present on the sensor for generating the desired frequency of the sound waves.
pins of the hcsr-04
1. VCC
2. GROUND
3. TRIG
4. ECHO
The 5v supply is connected to the VCC pin of the ultrasonic sensor.
Connect the -ve or GND to the ground pin of the ultrasonic sensor.
The ultrasonic sound pulses are triggered by using the trig pin, the trig pin is set to the high for 10 10micro seconds and then the sensor releases the ultrasonic sound waves.
The echo gets high after the sensor releases the ultrasonic sound waves, and it remains high until the sensor receives the transmitted sound wave by bouncing back due to hitting the object, after receiving the sound wave the echo pin gets low.
SPECIFICATIONS:
The measuring range of the hc-sr04 is 2cm to 400cm.
The operating voltage is 5v.
The operating current is 15ma.
The maximum current drawn by the sensor is 20ma.
The working temperature of the sensor is -15 to 70.
The frequency of the sound wave released by the sensor is 40khz.
The measuring angle of the sensor is 15 degrees
