Distance Display

Note

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Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

Name	Includes Arduino board	PURCHASE LINK
Ultimate Sensor Kit	Arduino Uno R4 Minima	BUY
Elite Explorer Kit	Arduino Uno R4 WiFi	BUY
3 in 1 Ultimate Starter Kit	Arduino Uno R4 Minima	BUY
Universal Maker Sensor Kit	×	BUY

Course Introduction

In this project, we use an ultrasonic sensor and an I2C 1602 LCD with an Arduino board to create a real-time distance measurement display system.

The ultrasonic sensor continuously measures the distance to an obstacle, and the result is shown on the LCD screen in centimeters.

The system updates the display approximately every 800 milliseconds, making it suitable for simple proximity detection applications.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino UNO R4 WIFI	1	BUY
2	USB Type-C cable	1
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	Ultrasonic Sensor Module	1	BUY
6	I2C LCD 1602	1	BUY

Wiring

Common Connections:

I2C LCD 1602
- SDA: Connect to A4 on the Arduino.
- SCL: Connect to A5 on the Arduino.
- GND: Connect to breadboard’s negative power bus.
- VCC: Connect to breadboard’s red power bus.
Ultrasonic Sensor Module
- Trig: Connect to 4 on the Arduino.
- Echo: Connect to 3 on the Arduino.
- GND: Connect to breadboard’s negative power bus.
- VCC: Connect to breadboard’s red power bus.

Writing the Code

Note

You can copy this code into Arduino IDE.
To install the library, use the Arduino Library Manager and search for LiquidCrystal I2C and install it.
Don’t forget to select the board(Arduino UNO R4 WIFI) and the correct port before clicking the Upload button.

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // initialize the Liquid Crystal Display object with the I2C address 0x27, 16 columns and 2 rows

// Define the pin numbers for the ultrasonic sensor
const int echoPin = 3;
const int trigPin = 4;

void setup() {
  pinMode(echoPin, INPUT);   // Set echo pin as input
  pinMode(trigPin, OUTPUT);  // Set trig pin as output

  lcd.init();       // initialize the LCD
  lcd.clear();      // clear the LCD display
  lcd.backlight();  // Make sure backlight is on
}

void loop() {
  float distance = readDistance();  // Call the function to read the sensor data and get the distance

  lcd.setCursor(0, 0);           //Place the cursor at Line 1, Column 1. From here the characters are to be displayed
  lcd.print("Distance:");        ////Print Distance: on the LCD
  lcd.setCursor(0, 1);           //Set the cursor at Line 1, Column 0
  lcd.print("               ");  //Here is to leave some spaces after the characters so as to clear the previous characters that may still remain.
  lcd.setCursor(7, 1);           //Set the cursor at Line 1, Column 7.
  lcd.print(distance);           // print on the LCD the value of the distance converted from the time between ping sending and receiving.
  lcd.setCursor(14, 1);          //Set the cursor at Line 1, Column 14.
  lcd.print("cm");               //print the unit "cm"

  delay(800);  // Delay for 800 milliseconds before repeating the loop
}

// Function to read the sensor data and calculate the distance
float readDistance() {
  digitalWrite(trigPin, LOW);   // Set trig pin to low to ensure a clean pulse
  delayMicroseconds(2);         // Delay for 2 microseconds
  digitalWrite(trigPin, HIGH);  // Send a 10 microsecond pulse by setting trig pin to high
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);  // Set trig pin back to low

  // Measure the pulse width of the echo pin and calculate the distance value
  float distance = pulseIn(echoPin, HIGH) / 58.00;  // Formula: (340m/s * 1us) / 2
  return distance;
}