Arduino Ultrasonic Range finder

In previous topic of Arduino Ultrasonic Distance Sensor, we have used a four-terminal Ultrasonic sensor.

Here, we will use a three-terminal Ultrasonic sensor, which is shown below:

It has three terminal GND (Ground), 5V, and SIG (signal). The process and the function of this sensor is similar to the Ultrasonic Distance Sensor.

The frequency waves travel through the air and strike the object on its path. The waves bounce back from the object and reach back to the module.

The Ultrasonic Range sensor pings the obstacles or objects with the ultrasound.

It detects the range from 3 cm or 4m or 400 cm.

The example of such a sensor is:

SEN136B5B

It is a sensor from SeedStudio. We need to switch the state between HIGH and LOW to notice the output.

Let's start the project.

Hardware Required

The components required to create the project are listed below:

Arduino UNO R3 board (We can also use any Arduino board)
Jump wires
Ultrasonic sensor
Breadboard

Structure of the project

The structure of the project is shown below:

Procedure

The steps to connect the Ultrasonic sensor to the board are listed below:

Connect 5V pin of the sensor to 5V of the Arduino board.
Connect the GND pin of the sensor to the GND of the Arduino board.
Connect the SIG pin of the sensor to pin 8 of the Arduino board.

Sketch

Consider the below code:

const int pinTOping = 7;
void setup() {
 
  Serial.begin(9600); //Serial communication at 9600 bps rate
  Serial.println("Test for the Ultrasonic range sensor");
}
void loop() 
{
  // initialzing the variables using long data type
  long TIMEduration, in, cm;
  // The PING))) is triggered by a HIGH pulse valu2 of 2 or more microseconds.
  // We have specified short time to clean HIGH pulse:
  pinMode(pinTOping, OUTPUT);
  digitalWrite(pinTOping, LOW);
  delayMicroseconds(4);
  digitalWrite(pinTOping, HIGH);
  delayMicroseconds(8);
  digitalWrite(pinTOping, LOW);
  // We have used the same pin to read the signal from the PING)), which is a HIGH pulse
  // the time is measured in microseconds
  pinMode(pinTOping, INPUT);
  TIMEduration = pulseIn(pinTOping, HIGH);
  // convert the time into a distance
  in = microsecondsToIn(TIMEduration);
  cm = microsecondsToCm(TIMEduration);
  Serial.print(in);
  Serial.print("inches, ");
  Serial.print(cm);
  Serial.print("centimeters");
  Serial.println();
  delay(200); //time delay of 200 microseconds
}
long microsecondsToIn(long microseconds) {
  //  there are 73.746 microseconds per inch according to PING datasheet 
  // we need to divide the distance by 2
  //It is because the ping travels forward and bounces backward
  return microseconds / 74 / 2;
}
long microsecondsToCm(long microseconds) {
  // The speed of sound is 340 m/s 
  return microseconds / 29 / 2;
}