Arduino - Ultrasonic Sensor - LCD

Hardware Required

1×Arduino UNO or Genuino UNO
1×USB 2.0 cable type A/B
1×Ultrasonic Sensor
n×Jumper Wires
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About Ultrasonic Sensor and LCD

If you do not know about Ultrasonic sensor and LCD (pinout, how it works, how to program ...), learn about them in the following tutorials:

Wiring Diagram

  • Wiring diagram
  • Arduino Ultrasonic Sensor LCD Wiring Diagram

    Image is developed using Fritzing. Click to enlarge image

  • Real wiring
  • Arduino Ultrasonic LCD Wiring Diagram

    Image is developed using Fritzing. Click to enlarge image

Arduino Code

/* * Created by * * This example code is in the public domain * * Tutorial page: */ #include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x3F, 16, 2); // I2C address 0x3F, 16 column and 2 rows int trigPin = 9; // TRIG pin int echoPin = 8; // ECHO pin float duration_us, distance_cm; void setup() { lcd.init(); // initialize the lcd lcd.backlight(); // open the backlight pinMode(trigPin, OUTPUT); // config trigger pin to output mode pinMode(echoPin, INPUT); // config echo pin to input mode } void loop() { // generate 10-microsecond pulse to TRIG pin digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); // measure duration of pulse from ECHO pin duration_us = pulseIn(echoPin, HIGH); // calculate the distance distance_cm = 0.017 * duration_us; lcd.clear(); lcd.setCursor(0, 0); // start to print at the first row lcd.print("Distance: "); lcd.print(distance_cm); delay(500); }

Quick Steps

  • Connect Arduino to PC via USB cable
  • Open Arduino IDE, select the right board and port

On Arduino IDE, Go to Tool Manage Libraries

Arduino add library
  • Search “LiquidCrystal I2C”, then find the LiquidCrystal_I2C library by Frank de Brabander
  • Click Install button to install LiquidCrystal_I2C library.
  • Arduino LiquidCrystal I2C library
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Arduino IDE Upload Code
  • Put the sensor on hot and cold water, or grasp the sensor by your hand
  • See the result in LCD
  • Arduino Ultrasonic LCD Wiring Diagram

    Image is developed using Fritzing. Click to enlarge image

If LCD displays nothing, see Troubleshooting on LCD I2C

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

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