How to Make an Ultrasonic Range Finder Using an LCD and Arduino





Introduction: How to Make an Ultrasonic Range Finder Using an LCD and Arduino

About: My name is Andrew Falcon and I am a thirteen-year-old inventor, app developer, entrepreneur, student, and athlete. Here on my Instructables account you can expect to find step-by-step tutorials on some of th...

In this Arduino tutorial I will show you how to use the HC-SR04 ultrasonic sensor and integrate it with an LCD display, so that it can display the distance between the sensor and certain objects.

Materials Needed:

- Arduino UNO

- Breadboard

- 16 x 2 LCD Display

- HC-SR04 Ultrasonic Sensor

- 10K Potentiometer (Comes with LCD display linked above)

- Jumper Cables

Step 1: Connecting HC-SR04 Ultrasonic Sensor

The HC-SR04 ultrasonic sensor has 4 pins... The VCC pin, trig pin, echo pin, and GND pin. Like the diagram above shows, the VCC pin connects to +5V on the breadboard, the GND pin connects to GND on the breadboard, the trig pin connects to digital pin 11 of the Arduino, and the echo pin connects to digital pin 10 of the Arduino.

Step 2: Connecting LCD and Potentiometer

In order to connect the the LCD to the breadboard, I recommend that you solder a pin header strip to the connectors on the display. The connections for the LCD display are as follows:

- LCD VSS pin to Arduino GND on breadboard

- LCD VDD pin to Arduino 5V on breadboard

- LCD VO pin to 10k Potentiometer center pin

- LCD RS pin to digital pin 1

- LCD RW pin to Arduino GND on breadboard

- LCD Enable pin to digital pin 2

- LCD D4 pin to digital pin 4

- LCD D5 pin to digital pin 5

- LCD D6 pin to digital pin 6

- LCD D7 pin to digital pin 7

- LCD A pin to +5V on breadboard

- LCD K pin to GND on breadboard

The remaining pins of the 10K potentiometer connect to +5V on the breadboard and GND.

Step 3: Supplying Power

For this project, we can supply power to the Arduino through any +5V power source. You can use a USB port from your computer to power the Arduino, but in this project I will be using a portable battery. Before you connect a power source to your Arduino, make sure that the +5V port on the Arduino is connected to the +5V on the breadboard. Do the same and connect the GND port on the Arduino to the GND of the breadboard.

Step 4: Get the Code

#include 'LiquidCrystal.h' // Replace ' ' with < >

LiquidCrystal lcd(1, 2, 4, 5, 6, 7); // Creates an LCD object. Parameters: (rs, enable, d4, d5, d6, d7)

// defines pins numbers

const int trigPin = 11;

const int echoPin = 10;

// defines variables

long duration;

int distance;

void setup() {

lcd.begin(16,2); // Initializes the interface to the LCD screen, and specifies the dimensions

pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output

pinMode(echoPin, INPUT); // Sets the echoPin as an Input


void loop() {

// Clears the trigPin digitalWrite

(trigPin, LOW);


// Sets the trigPin on HIGH state for 10 micro seconds

digitalWrite(trigPin, HIGH);


digitalWrite(trigPin, LOW);

// Reads the echoPin, returns the sound wave travel time in microseconds

duration = pulseIn(echoPin, HIGH);

// Calculating the distance

distance= duration*0.034/2;

// Prints the distance on LCD

lcd.setCursor(0,0); // Sets the location at which subsequent text written to the LCD will be displayed

lcd.print("Distance: "); // Prints string "Distance" on the LCD

lcd.print(distance); // Prints the distance value from the sensor

lcd.print(" cm");





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    Nice system. How accurate is it with objects that are not right in front of it?