How to Make an Arduino Radar




Introduction: How to Make an Arduino Radar

This is a radar, designed to detect the distance and direction an object is from the ultrasonic sensor. With the ultrasonic sensor connected to a servo, it has the ability to rotate 180 degress, similar to a radar utilised to detect the position of planes. As the radar wasn't my original idea, I have also made improvements and adjustments to the original source of this project. This includes 3D printing an ultrasonic sensor bracket, laser cutting a box to make it look cleaner, and the inclusion of a buzzer. The original inspiration for this project can be viewed here: as it gave me a good understanding into what the end result was going to look like, but also gave me ideas on improvements I could make to the overall aesthetics of the project.

Step 1: Materials and Programs

The materials required for this build include:

- 1 Servo

- 1 Ultrasonic sensor

- 1 Buzzer

- 1 Bread board

- 1 UNO R3 Arduino

- Heaps of wires

Programs required to make this radar:

- Arduino IDE

- Processing 3.4

To download the above programs onto your computer, follow the links below:



Step 2: Arduino Code

This is the arduino code which basically controls the movement and input of the servo and sensor. This was copied from the youtube video and seemed to work nicely with my arduino board and computer.

// Includes the servo library
#include <Servo.h>. 
// Defines Trig and Echo pins of the Ultrasonic Sensor
const int trigPin = 10;
const int echoPin = 11;
#define buzzerPin A0 //Defines the pin A0 as an output to buzzerPin
// 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
  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++){  
  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
  tone(buzzerPin, 10000 / distance);
  // Repeats the previous lines from 165 to 15 degrees
  for(int i=165;i>15;i--){  
  distance = calculateDistance();
  tone(buzzerPin, 10000 / distance); //Produces a different tone according to the distance the object is from the sensor
// Function for calculating the distance measured by the Ultrasonic sensor
int calculateDistance(){ 
  digitalWrite(trigPin, LOW); 
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH); 
  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;

Step 3: Processing Code

Here is the code I used for the processing program to take the information from the ultrasonic sensor, and turn it into the display that it creates. This was a code the I copied from the video which worked really well, it only needed a few tweaks.

<p>p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px 'Helvetica Neue'; color: #000000; -webkit-text-stroke: #000000}<br>p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px 'Helvetica Neue'; color: #000000; -webkit-text-stroke: #000000; min-height: 12.0px}
span.s1 {font-kerning: none}</p><p>import processing.serial.*; // imports library for serial communication</p><p>import java.awt.event.KeyEvent; // imports library for reading the data from the serial port</p><p>import;</p><p>Serial myPort; // defines Object Serial</p><p>// defubes variables</p><p>String angle="";</p><p>String distance="";</p><p>String data="";</p><p>String noObject;</p><p>float pixsDistance;</p><p>int iAngle, iDistance;</p><p>int index1=0;</p><p>int index2=0;</p><p>PFont orcFont;</p><p>void setup() {</p><p> size (1200, 700); // ***CHANGE THIS TO YOUR SCREEN RESOLUTION***</p><p> smooth();</p><p> myPort = new Serial(this,"/dev/cu.usbmodem143401", 9600); // starts the serial communication</p><p> myPort.bufferUntil('.'); // reads the data from the serial port up to the character '.'. So actually it reads this: angle,distance.</p><p>}</p><p>void draw() {</p><p>  fill(98,245,31);</p><p>  // simulating motion blur and slow fade of the moving line</p><p>  noStroke();</p><p>  fill(0,4); </p><p>  rect(0, 0, width, height-height*0.065); </p><p>  fill(98,245,31); // green color</p><p>  // calls the functions for drawing the radar</p><p>  drawRadar(); </p><p>  drawLine();</p><p>  drawObject();</p><p>  drawText();</p><p>}</p><p>void serialEvent (Serial myPort) { // starts reading data from the Serial Port</p><p>  // reads the data from the Serial Port up to the character '.' and puts it into the String variable "data".</p><p>  data = myPort.readStringUntil('.');</p><p>  data = data.substring(0,data.length()-1);</p><p>  index1 = data.indexOf(","); // find the character ',' and puts it into the variable "index1"</p><p>  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</p><p>  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</p><p>  // converts the String variables into Integer</p><p>  iAngle = int(angle);</p><p>  iDistance = int(distance);</p><p>}</p><p>void drawRadar() {</p><p>  pushMatrix();</p><p>  translate(width/2,height-height*0.074); // moves the starting coordinats to new location</p><p>  noFill();</p><p>  strokeWeight(2);</p><p>  stroke(98,245,31);</p><p>  // draws the arc lines</p><p>  arc(0,0,(width-width*0.0625),(width-width*0.0625),PI,TWO_PI);</p><p>  arc(0,0,(width-width*0.27),(width-width*0.27),PI,TWO_PI);</p><p>  arc(0,0,(width-width*0.479),(width-width*0.479),PI,TWO_PI);</p><p>  arc(0,0,(width-width*0.687),(width-width*0.687),PI,TWO_PI);</p><p>  // draws the angle lines</p><p>  line(-width/2,0,width/2,0);</p><p>  line(0,0,(-width/2)*cos(radians(30)),(-width/2)*sin(radians(30)));</p><p>  line(0,0,(-width/2)*cos(radians(60)),(-width/2)*sin(radians(60)));</p><p>  line(0,0,(-width/2)*cos(radians(90)),(-width/2)*sin(radians(90)));</p><p>  line(0,0,(-width/2)*cos(radians(120)),(-width/2)*sin(radians(120)));</p><p>  line(0,0,(-width/2)*cos(radians(150)),(-width/2)*sin(radians(150)));</p><p>  line((-width/2)*cos(radians(30)),0,width/2,0);</p><p>  popMatrix();</p><p>}</p><p>void drawObject() {</p><p>  pushMatrix();</p><p>  translate(width/2,height-height*0.074); // moves the starting coordinats to new location</p><p>  strokeWeight(9);</p><p>  stroke(255,10,10); // red color</p><p>  pixsDistance = iDistance*((height-height*0.1666)*0.025); // covers the distance from the sensor from cm to pixels</p><p>  // limiting the range to 40 cms</p><p>  if(iDistance<40){</p><p>    // draws the object according to the angle and the distance</p><p>  line(pixsDistance*cos(radians(iAngle)),-pixsDistance*sin(radians(iAngle)),(width-width*0.505)*cos(radians(iAngle)),-(width-width*0.505)*sin(radians(iAngle)));</p><p>  }</p><p>  popMatrix();</p><p>}</p><p>void drawLine() {</p><p>  pushMatrix();</p><p>  strokeWeight(9);</p><p>  stroke(30,250,60);</p><p>  translate(width/2,height-height*0.074); // moves the starting coordinats to new location</p><p>  line(0,0,(height-height*0.12)*cos(radians(iAngle)),-(height-height*0.12)*sin(radians(iAngle))); // draws the line according to the angle</p><p>  popMatrix();</p><p>}</p><p>void drawText() { // draws the texts on the screen</p><p>  pushMatrix();</p><p>  if(iDistance>40) {</p><p>  noObject = "Out of Range";</p><p>  }</p><p>  else {</p><p>  noObject = "In Range";</p><p>  }</p><p>  fill(0,0,0);</p><p>  noStroke();</p><p>  rect(0, height-height*0.0648, width, height);</p><p>  fill(98,245,31);</p><p>  textSize(25);</p><p>  text("10cm",width-width*0.3854,height-height*0.0833);</p><p>  text("20cm",width-width*0.281,height-height*0.0833);</p><p>  text("30cm",width-width*0.177,height-height*0.0833);</p><p>  text("40cm",width-width*0.0729,height-height*0.0833);</p><p>  textSize(40);</p><p>  text("Ryan's Radar", width-width*0.875, height-height*0.0277);</p><p>  text("Angle: " + iAngle +" °", width-width*0.48, height-height*0.0277);</p><p>  text("Distance: ", width-width*0.26, height-height*0.0277);</p><p>  if(iDistance<40) {</p><p>  text("        " + iDistance +" cm", width-width*0.225, height-height*0.0277);</p><p>  }</p><p>  textSize(25);</p><p>  fill(98,245,60);</p><p>  translate((width-width*0.4994)+width/2*cos(radians(30)),(height-height*0.0907)-width/2*sin(radians(30)));</p><p>  rotate(-radians(-60));</p><p>  text("30°",0,0);</p><p>  resetMatrix();</p><p>  translate((width-width*0.503)+width/2*cos(radians(60)),(height-height*0.0888)-width/2*sin(radians(60)));</p><p>  rotate(-radians(-30));</p><p>  text("60°",0,0);</p><p>  resetMatrix();</p><p>  translate((width-width*0.507)+width/2*cos(radians(90)),(height-height*0.0833)-width/2*sin(radians(90)));</p><p>  rotate(radians(0));</p><p>  text("90°",0,0);</p><p>  resetMatrix();</p><p>  translate(width-width*0.513+width/2*cos(radians(120)),(height-height*0.07129)-width/2*sin(radians(120)));</p><p>  rotate(radians(-30));</p><p>  text("120°",0,0);</p><p>  resetMatrix();</p><p>  translate((width-width*0.5104)+width/2*cos(radians(150)),(height-height*0.0574)-width/2*sin(radians(150)));</p><p>  rotate(radians(-60));</p><p>  text("150°",0,0);</p><p>  popMatrix(); </p><p>}</p>

Step 4: Ultrasonic Sensor Bracket

As my inspiration for this project hadn't included any sort of bracket to hold the ultrasonic sensor in place, I decided that it would be a good idea to 3D print this bracket to give the finished design a cleaner look, and make everything easier to put together. The section which holds the ultrasonic sensor ended up fitting relatively tightly around the ultrasonic sensor, doing a good job at keeping it in place. However, the hole cut out underneath for the servo arm to go in is slightly too big, so I needed to add a lot of glue to keep it in place. But overall, it works quite nicely and gives the design a good look.

Step 5: Laser-Cut Box Design

This box was implemented to give the project a clean and professional look. It does a good job at concealing all of the wires and the arduino board itself. To create the actual box design, I used the website to get the finger edges to join each side of the box together. This was a very useful website as it saves me heaps of time and is very easy to use. As you can see from the finished product of the radar, I cut out measured holes in the side and top of the design to allow for the parts of the project which needed to be on the outside. This included holes for the servo, which I stuck to the box from underneath, wires to the ultrasonic sensor, the buzzer, and to the arduino board itself from the computer. It is quite big (there is a lot of room in the box) but at least it gives you a lot of room to work with and nothing is ever cramped. If you were to make a box design yourself, you could definitely make ti smaller and everything would still fit.

Step 6: Wiring Construction

As per the arduino code, the ultrasonic sensor has to be wired to pin 10 and 11. Though, as well as with all ultrasonic sensors, it also has to be wired to the ground and 5V pin. The servo has to be connected to the pin 12 (myServo.attach(12);) and it also has to be connected to the ground and 5V pins. As for the buzzer, it just connects to ground and the analog output pin A0. Once you have attached all the necessary items for the radar, your circuit should look somewhat like the diagram above. Also, try and keep everything neat! Once the circuit is in the box, it the wires are all extremely tangled, there is the chance a wire or two can slip out of place and cause your radar to malfunction. It happened to me, and I found keeping it neat from then on reduced these occurrences.

Step 7: Assembly

Assemble the laser cut box using strong super glue, so there is no chance that it will slip apart after you have finished the radar. I found it easier to use some books to hold up one of the sides of the box so I could then glue the adjacent side. After holding it there for 5 or so minutes, I would then continue to the next side and so on. Remember no to glue one of the ends on, as you will obviously need to put in and take out the radar. Once the glue on your box has hardened, you can continue with your assembly. Firstly, I glued the buzzer to the top of the case (shown above) and then when that was dry, I fed the wires through the relative hole and connected them to the buzzer. When it came to the servo, I glued the little wings of the servo underneath the box, so just the top part of the servo was showing. This allowed the whole thing to look aesthetic while also maintaining it's practicality, with the head of the servo readily available for easy access. Then with the ultrasonic sensor in the 3D printed bracket, attach the bracket to the servo using glue so that it is secure. Once this is done, your project is ready to test!

Step 8: Execution

First start by connecting your computer to the arduino board. Next, open up both programs. Once the arduino code has loaded, upload it to the board. This should begin the servo and the buzzer, so noises will be produced and the servo will turn accordingly. Then, when the processing code has loaded, click run and if everything runs smoothly, the animation of the radar should appear. If this doesn't happen, check that the port name you are using is exactly the same as what it says in the code. For example if I am using the port "/dev/cu.usbmodem143401" , make sure the line of code in processing says "myPort = new Serial(this,"/dev/cu.usbmodem143401", 9600);". This should fix everything and it should all run smoothly. The process of getting it up and running can all be seen on the video link above of it working and detecting objects.

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    Question 1 year ago on Step 2

    Can you provide us some insight on where to get the materials?


    Answer 1 year ago

    Apologies, but my school provided me with the materials to make this so unfortunately I do not know the answer to this. But if I were to make an educated guess, your local electronics store should sell these items as they are quite common. Hope this helps!


    2 years ago

    How can i open up the menue/ radar?
    How can i add LEDs in?


    Question 2 years ago on Step 3

    dear sir that ultrasonic code not working please help me. i am using board Arduino leonardo


    Question 2 years ago on Step 8

    Great design....Thanks. I'm wondering if this could be used as a speed sensor to feed an LED with the speed displayed? My street has become a thoroughfare for Many cars and they are constantly going over the 35mph limit. If I could display their actual speed it might help to make them aware of the danger they are posing as they top the hill in front of my house. They have NO way of seeing what's on the other side. Kids or pets.

    Penolopy Bulnick
    Penolopy Bulnick

    2 years ago

    Fun project and your photos are really easy to follow along with :)