ESP32 - Ultrasonic Sensor - LCD

This tutorial instructs you how to use ESP32 to measure distance and display it on LCD using Ultrasonic sensor.

Hardware Used In This Tutorial

1×ESP-WROOM-32 Dev Module
1×Micro USB Cable
1×LCD I2C
1×Ultrasonic Sensor
n×Jumper Wires
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Introduction to Ultrasonic Sensor and LCD

We have specific tutorials about Ultrasonic sensor and LCD. Each tutorial contains detailed information and step-by-step instructions about hardware pinout, working principle, wiring connection to ESP32, ESP32 code... Learn more about them at the following links:

Wiring Diagram

wiring diagram between esp32 ultrasonic sensor lcd

This image is created using Fritzing. Click to enlarge image

ESP32 Code

/* * This ESP32 code is created by esp32io.com * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-ultrasonic-sensor-lcd */ #include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x3F, 16, 2); // I2C address 0x3F, 16 column and 2 rows #define TRIG_PIN 26 // ESP32 pin GIOP26 connected to Ultrasonic Sensor's TRIG pin #define ECHO_PIN 25 // ESP32 pin GIOP25 connected to Ultrasonic Sensor's ECHO pin float duration_us, distance_cm; void setup() { lcd.init(); // initialize the lcd lcd.backlight(); // open the backlight pinMode(TRIG_PIN, OUTPUT); // config trigger pin to output mode pinMode(ECHO_PIN, INPUT); // config echo pin to input mode } void loop() { // generate 10-microsecond pulse to TRIG pin digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10); digitalWrite(TRIG_PIN, LOW); // measure duration of pulse from ECHO pin duration_us = pulseIn(ECHO_PIN, 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); }

※ NOTE THAT:

The LCD I2C address can be different from each manufacturer. In the code, we used address of 0x27 that is specified by DIYables manufacturer

Quick Instructions

  • If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
  • Do the wiring as above image.
  • Connect the ESP32 board to your PC via a micro USB cable
  • Open Arduino IDE on your PC.
  • Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.

On Arduino IDE, Navigate to Tools Manage Libraries

ESP32 add library
  • Type “LiquidCrystal I2C” on the search box, then look for the LiquidCrystal_I2C library by Frank de Brabander
  • Click Install button to install LiquidCrystal_I2C library.
  • ESP32 LiquidCrystal I2C library
  • Copy the above code and paste it to Arduino IDE.
  • Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
  • Arduino IDE Upload Code
  • Put the sensor on hot and cold water, or grasp the sensor by your hand
  • See the result in LCD
  • wiring diagram between esp32 ultrasonic lcd

    This image is created using Fritzing. Click to enlarge image

If LCD displays nothing, see Troubleshooting on LCD I2C

Line-by-line Code Explanation

The above ESP32 code contains line-by-line explanation. Please read the comments in the code!

Video Tutorial

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