ULTRASONIC SENSOR
An
ultrasonic sensor uses a transducer to send and receive ultrasonic pulses that
relay back information about an object’s proximity.
The
sensor consists of 4pins :
.VCC-5V
,INPUT POWER
.TRIG-Trigger
input
.ECHO-Echo
Output
.GND-Ground
It
has two modules one transmitter and one receiver.
HARDWARE SETUP OF ULTRASONIC SENSOR:
Connect
Trig pin to pin D12 on the Arduino board.
Connect
the Echo pin to pin D13 on the Arduino board.
Connect
VCC pin to 5V pin on the Arduino board.
Connect
the GND pin to the GND pin on the Arduino board.
Explanation:
Provide
input to TRIG input then enables the module to transmit ultrasonic burst.
If
there is an obstacle detected in front of the module then it will reflect those
ultrasonic waves.
If
the signal comes back, the ECHO output will be high for some specific time of
duration for sending and receiving ultrasonic signals.
The
formula used to calculate distance :
Distance
=(speed*time)/2
The basic components required for the
setup:
.HC-SR04
ultrasonic sensor
.Arduino
Uno
.Breadboard
.Jumper
wires(as per requirements)
Basic
specifications of ultrasonic sensor:
.Input
current: 15 mA
.Output
voltage: 0 – 5V
.Modulation
frequency: 40 HZ
.Beam
Angle: Max. 15 degrees
.Distance:
2 cm – 400cm
.Accuracy:
0.3 cm
.Output
cycle: 50ms
Basic
dimensions of the ultrasonic sensor:
.Length:
45 mm
.Height:
20 mm
.Height
of transmitter and receiver: 11 mm.
.The
diameter of the transmitter and Receiver: 16 mfm
BASIC STEPS FOR PROGRAM EXECUTION
Open
the Arduino IDE software on your desktop. Open a new sketch File by clicking
New. The Arduino code should contain two functions as void setup() and void
loop(). All pinMode declarations are made in void setup(). The functions inside
the void loop() will run infinitely. These are the basic steps you can follow
to write the program for interfacing.
SMALL STEPS FOR PROGRAM EXECUTION
Serial.begin(9600) – to set the
baud-rate for the sensor reading.
pinMode(pin, mode) – to declare the
pin and specify that it is an input pin or output pin.
digitalWrite(pin, HIGH/LOW) – to
specify the particular pin as high or low.
delay(µs) – to delay the process
executing for some microseconds.
.PulseIn (echo-pin, mode) – Reads a
pulse on a pin(either HIGH or LOW).
.print(data)- to print the reading on
the serial monitor.
Basic code for demonstration of
ultrasonic sensor :
Condition :
when the Obstacle is
within 10cm of range then the inbuilt led of Arduino will switch on
Else it will remain off
const int trigpin=9;
const int echopin=10;
long duration;
int distance;
void setup() {
pinMode(trigpin,OUTPUT);
pinMode(echopin,INPUT);
pinMode(13,OUTPUT);
//using the arduino's inbuilt led for
output//
Serial.begin(9600);
//to set the baud rate for the
serial
communication//
}
void loop() {
digitalWrite(trigpin,LOW);
delayMicroseconds(2);
digitalWrite(trigpin,HIGH);
delayMicroseconds(10);
digitalWrite(trigpin,LOW);
duration=pulseIn(echopin,HIGH);
distance=duration*0.034/2; //distance
of the obstacle in cm//
Serial.println(distance);
//printing the calculated distance in
the serial monitor//
delay(1000);
if(distance<=10)
{
digitalWrite(13,HIGH);
//led on if obstacle is within the range
10cm//
}
else
{
digitalWrite(13,LOW);
}
}
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