Arduino Radar Project – Ultrasonic Based Radar – Connection and Code

Do you know? For the first time, radar was developed as a method of detecting enemy aircraft in World War 2. Along with the developments in technology, these days it is used in a wide range of sectors. In the last few decades, there have been significant advancements in the use of radar technology.

In this project, we are going to design an Arduino radar project using an ultrasonic sensor for detection. An Arduino microcontroller makes electronics more disciplined.

This Arduino radar project aims to achieve a radar system prototype based on an Arduino board that detects stationary and moving objects. The radar system has different performance specifications, and it is also available in a variety of sizes.

How does radar work?

Radio detection and ranging is the meaning of the term RADAR. Radar is an object detection system that uses microwaves to determine the range, altitude, direction, and speed of objects within about a 100-mile radius of their location.

The radar antenna transmits radio waves or microwaves that bounce off any object in their path. Due to this, we can easily determine the object in the radar range.

The basic operation principle is:

A radar is an electromagnetic sensor that is used to detect and locate an object.

Radio waves or microwaves are radiated out from the radar into free space. Some of these waves are intercepted by reflecting objects.

These intercepted radio waves hit the target and are reflected in many different directions. Some of these waves can be directed back toward the radar, where they are received and amplified.

If these waves are received again at their origin, then it means an object is in the propagation direction.

The modern radar system is very advanced and used in highly diverse applications such as air traffic control, air defense systems, radar astronomy, antimissile systems, outer space surveillance systems, and many more.

What is an ultrasonic sensor?

An ultrasonic sensor is a proximity sensor that is used to measure the distance of a target or object. It detects the object by transmitting ultrasonic waves and converts the reflected waves into an electrical signal. These sound waves travel faster than the speed of the sound that humans can hear.

It has two main components: the transmitter and the receiver. The transmitter emits the sound using a piezoelectric crystal, and the receiver encounters the sound after it has traveled to and from the target.

For the calculation of the object distance, the sensor measures the time taken by the signal to travel from the transmission of the sound by the transmitter to the reflection back toward the receiver.

The formula for this calculation is,

D = ½ T x C 

Where,

• D = distance,
• T = time
• C = speed of sound, which is 343 meters per second.

These sensors are mostly found in automobile self-parking technology and anti-collision safety systems; they are also used in robotic obstacle detection systems, manufacturing technology, and many more. To know more about the ultrasonic sensor, refer to the ultrasonic sensor working principle.

What is a servo motor?

The servo motor is a simple DC motor that can be controlled for specific angular rotation with the help of additional servomechanism. This motor will only rotate as much as we want and then stop. The servo motor is a closed-loop mechanism that uses positional feedback to control the speed and position.

This closed-loop system includes a control circuit, servo motor, shaft, potentiometer, drive gears, amplifier, and either an encoder or resolver.

The servo motor is unlike a standard electric motor, which starts and stops according to the power input. According to the signal, the servo motor will work.

Nowadays, servo motors are widely used in industrial and robotics applications. They are also commonly seen in remote-controlled toy cars, RC planes, and CD or DVD players. Besides these, we see hundreds of applications in our daily lives that use a servo motor. To know more about the servo motor, refer to the servo motor working principle.

Preparing the Fixture for the Arduino Radar Project

After making the connections, to build the fixture for this construction, I used a mounting bracket as shown in the below image to fix the ultrasonic sensor in the Arduino radar project.

After fixing it, the mounting bracket is screwed to the servo motor. Kindly use the DST (double-sided) tape to fix the servo motor firmly to the surface so that it can easily handle the weight of the bracket and the ultrasonic sensor.

This step is optional. You can also make a simple structure with cardboard to mount the ultrasonic sensor with a servo motor.

Hardware Connection for the Arduino Radar Project:

The below image shows the connection to the Arduino radar project. The connections are very simple. Here, we have interfaced the ultrasonic sensor and servo motor with an Arduino Uno. The connection details of the Arduino radar project are:

Arduino Uno	Ultrasonic Sensor	Servo Motor
Vcc	Vcc	Vcc
Gnd	Gnd	Gnd
D10	Trig	-
D11	Echo	-
D12	-	Signal

Software Installation and Code for the Arduino Radar Project:

We need to use two pieces of software to complete this Arduino radar project. One is the Arduino IDE, and the other is the Processing IDE. Download both programs from the below links.

• Arduino IDE 1.8.13
• Processing IDE

Processing applications are visual arts-based software for learning to code. After downloading, extract the zip file, and you will get the processing application (.exe file).

In this Arduino radar project, we are using two codes: one for Arduino UNO and the other for Processing.

• Here is the Arduino source code for the Arduino radar project:

// Includes the Servo library
#include <Servo.h>. 
// Defines Tirg and Echo pins of the Ultrasonic Sensor
const int trigPin = 10;
const int echoPin = 11;
// Variables for the duration and the distance
long duration;
int distance;
Servo myServo; // Creates a servo object for controlling the servo motor
void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  Serial.begin(9600);
  myServo.attach(12); // Defines on which pin is the servo motor attached
}
void loop() {
  // rotates the servo motor from 15 to 165 degrees
  for(int i=15;i<=165;i++){  
  myServo.write(i);
  delay(30);
  distance = calculateDistance();// Calls a function for calculating the distance measured by the Ultrasonic sensor for each degree
  
  Serial.print(i); // Sends the current degree into the Serial Port
  Serial.print(","); // Sends addition character right next to the previous value needed later in the Processing IDE for indexing
  Serial.print(distance); // Sends the distance value into the Serial Port
  Serial.print("."); // Sends addition character right next to the previous value needed later in the Processing IDE for indexing
  }
  // Repeats the previous lines from 165 to 15 degrees
  for(int i=165;i>15;i--){  
  myServo.write(i);
  delay(30);
  distance = calculateDistance();
  Serial.print(i);
  Serial.print(",");
  Serial.print(distance);
  Serial.print(".");
  }
}
// Function for calculating the distance measured by the Ultrasonic sensor
int calculateDistance(){ 
  
  digitalWrite(trigPin, LOW); 
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH); 
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH); // Reads the echoPin, returns the sound wave travel time in microseconds
  distance= duration*0.034/2;
  return distance;
}

• Here is the processing code for the Arduino radar project:

import processing.serial.*; // imports library for serial communication
import java.awt.event.KeyEvent; // imports library for reading the data from the serial port
import java.io.IOException;
Serial myPort; // defines Object Serial
// defubes variables
String angle="";
String distance="";
String data="";
String noObject;
float pixsDistance;
int iAngle, iDistance;
int index1=0;
int index2=0;
PFont orcFont;
void setup() {
  
 size (1200, 700); // ***CHANGE THIS TO YOUR SCREEN RESOLUTION***
 smooth();
 myPort = new Serial(this,"COM5", 9600); // starts the serial communication
 myPort.bufferUntil('.'); // reads the data from the serial port up to the character '.'. So actually it reads this: angle,distance.
}
void draw() {
  
  fill(98,245,31);
  // simulating motion blur and slow fade of the moving line
  noStroke();
  fill(0,4); 
  rect(0, 0, width, height-height*0.065); 
  
  fill(98,245,31); // green color
  // calls the functions for drawing the radar
  drawRadar(); 
  drawLine();
  drawObject();
  drawText();
}
void serialEvent (Serial myPort) { // starts reading data from the Serial Port
  // reads the data from the Serial Port up to the character '.' and puts it into the String variable "data".
  data = myPort.readStringUntil('.');
  data = data.substring(0,data.length()-1);
  
  index1 = data.indexOf(","); // find the character ',' and puts it into the variable "index1"
  angle= data.substring(0, index1); // read the data from position "0" to position of the variable index1 or thats the value of the angle the Arduino Board sent into the Serial Port
  distance= data.substring(index1+1, data.length()); // read the data from position "index1" to the end of the data pr thats the value of the distance
  
  // converts the String variables into Integer
  iAngle = int(angle);
  iDistance = int(distance);
}
void drawRadar() {
  pushMatrix();
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location
  noFill();
  strokeWeight(2);
  stroke(98,245,31);
  // draws the arc lines
  arc(0,0,(width-width*0.0625),(width-width*0.0625),PI,TWO_PI);
  arc(0,0,(width-width*0.27),(width-width*0.27),PI,TWO_PI);
  arc(0,0,(width-width*0.479),(width-width*0.479),PI,TWO_PI);
  arc(0,0,(width-width*0.687),(width-width*0.687),PI,TWO_PI);
  // draws the angle lines
  line(-width/2,0,width/2,0);
  line(0,0,(-width/2)*cos(radians(30)),(-width/2)*sin(radians(30)));
  line(0,0,(-width/2)*cos(radians(60)),(-width/2)*sin(radians(60)));
  line(0,0,(-width/2)*cos(radians(90)),(-width/2)*sin(radians(90)));
  line(0,0,(-width/2)*cos(radians(120)),(-width/2)*sin(radians(120)));
  line(0,0,(-width/2)*cos(radians(150)),(-width/2)*sin(radians(150)));
  line((-width/2)*cos(radians(30)),0,width/2,0);
  popMatrix();
}
void drawObject() {
  pushMatrix();
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location
  strokeWeight(9);
  stroke(255,10,10); // red color
  pixsDistance = iDistance*((height-height*0.1666)*0.025); // covers the distance from the sensor from cm to pixels
  // limiting the range to 40 cms
  if(iDistance<40){
    // draws the object according to the angle and the distance
  line(pixsDistance*cos(radians(iAngle)),-pixsDistance*sin(radians(iAngle)),(width-width*0.505)*cos(radians(iAngle)),-(width-width*0.505)*sin(radians(iAngle)));
  }
  popMatrix();
}
void drawLine() {
  pushMatrix();
  strokeWeight(9);
  stroke(30,250,60);
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location
  line(0,0,(height-height*0.12)*cos(radians(iAngle)),-(height-height*0.12)*sin(radians(iAngle))); // draws the line according to the angle
  popMatrix();
}
void drawText() { // draws the texts on the screen
  
  pushMatrix();
  if(iDistance>40) {
  noObject = "Out of Range";
  }
  else {
  noObject = "In Range";
  }
  fill(0,0,0);
  noStroke();
  rect(0, height-height*0.0648, width, height);
  fill(98,245,31);
  textSize(25);
  
  text("10cm",width-width*0.3854,height-height*0.0833);
  text("20cm",width-width*0.281,height-height*0.0833);
  text("30cm",width-width*0.177,height-height*0.0833);
  text("40cm",width-width*0.0729,height-height*0.0833);
  textSize(40);
  text("Robu.in", width-width*0.875, height-height*0.0277);
  text("Angle: " + iAngle +" °", width-width*0.48, height-height*0.0277);
  text("Distance: ", width-width*0.26, height-height*0.0277);
  if(iDistance<40) {
  text("        " + iDistance +" cm", width-width*0.225, height-height*0.0277);
  }
  textSize(25);
  fill(98,245,60);
  translate((width-width*0.4994)+width/2*cos(radians(30)),(height-height*0.0907)-width/2*sin(radians(30)));
  rotate(-radians(-60));
  text("30°",0,0);
  resetMatrix();
  translate((width-width*0.503)+width/2*cos(radians(60)),(height-height*0.0888)-width/2*sin(radians(60)));
  rotate(-radians(-30));
  text("60°",0,0);
  resetMatrix();
  translate((width-width*0.507)+width/2*cos(radians(90)),(height-height*0.0833)-width/2*sin(radians(90)));
  rotate(radians(0));
  text("90°",0,0);
  resetMatrix();
  translate(width-width*0.513+width/2*cos(radians(120)),(height-height*0.07129)-width/2*sin(radians(120)));
  rotate(radians(-30));
  text("120°",0,0);
  resetMatrix();
  translate((width-width*0.5104)+width/2*cos(radians(150)),(height-height*0.0574)-width/2*sin(radians(150)));
  rotate(radians(-60));
  text("150°",0,0);
  popMatrix(); 
}

Output of Arduino Radar Project:

After uploading the code, the servo motors start running from 0 to 180 degrees and again back to 0 degrees. An ultrasonic sensor also rotates along with the servo as it is mounted on the motor.

Now, open the processing application and paste the above code. In this code, update the COM port number where your Arduino board is connected.

Now, run this processing code. If your code is right, then you will get a new window. This is the graphical representation of data from the ultrasonic sensor, which is represented on a radar-type display.

If an ultrasonic sensor detects any object within its range, you can see the same in the graphical representation. The below gif shows the output of the Arduino radar project.

Final Words

I hope this tutorial helps you understand the radar sensor, how it works, and the prototype of the Arduino radar project.

Tags : Radar system