Interfacing a Character I2C LCD with Arduino

Contents hide

1. Introduction

2. What is Character I2C LCD?

3. Hardware Components

3.1. Character I2C LCD Pinout

3.2. Character I2C LCD Circuit

3.2.1. Wiring / Connections

3.3. Installing Arduino IDE

3.4. Installing Libraries

3.5. Code

3.5.1. Code Explanation

4. Applications

5. Conclusion.

5.1. Related posts:

Introduction

Interfacing a character I2C LCD with Arduino can be an exciting and rewarding project for beginners and advanced makers alike. This project enables you to display information on a small LCD screen, which can be useful in various applications such as weather monitoring, timekeeping, and home automation. The I2C interface simplifies the wiring and saves valuable pins on the Arduino board.

In this article, we will discuss the necessary steps to interface a “Character I2C LCD” with Arduino and display some sample text on the screen.

What is Character I2C LCD?

A character I2C LCD (Liquid Crystal Display) is a type of display module that can be used to display text and symbols. It consists of a screen made up of a grid of pixels that can be controlled individually to display different characters. The I2C interface allows the LCD to communicate with other devices, such as microcontrollers like the Arduino, using only a few wires.

A character LCD can display a limited number of characters at a time, usually 16×2 or 20×4 characters, depending on the size of the screen. However, it is an efficient and cost-effective way to display information, particularly in applications where a larger, more complex graphical display is not necessary.

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Hardware Components

To interface an I2C Character LCD with Arduino, you’ll need the following hardware components to get started:

Components	Value	Qty
Arduino UNO	–	1
USB Cable Type A to B	–	1
DC Power for Arduino	–	1
Character I2C LCD	–	1
Jumper Wires	–	1

Character I2C LCD Pinout

Pin Name	Pin Description
GND	Ground pin
VCC	5V pin
SDA	Serial Data Pin
SCL	Serial Clock Pin

Character I2C LCD Circuit

Make connections according to the circuit diagram given below.

Wiring / Connections

Arduino	Character I2C LCD
5V	VCC
GND	GND
A4	SDA
A5	SCL

Installing Arduino IDE

First, you need to install Arduino IDE Software from its official website Arduino. Here is a simple step-by-step guide on “How to install Arduino IDE“.

Installing Libraries

Before you start uploading a code, download and unzip the following libraries at /Program Files(x86)/Arduino/Libraries (default), in order to use the sensor with the Arduino board. Here is a simple step-by-step guide on “How to Add Libraries in Arduino IDE“.

Wire.h

Code

Now copy the following code and upload it to Arduino IDE Software.

#include <Wire.h>

void setup() {
  Wire.begin();

  Serial.begin(9600);
  while (!Serial);
  Serial.println("\nI2C Scanner");
}

void loop() {
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for (address = 1; address < 127; address++ ) {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0) {
      Serial.print("I2C device found at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.print(address, HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error == 4) {
      Serial.print("Unknown error at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.println(address, HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);
}

Code Explanation

This Arduino code is used to scan for I2C devices connected to the Arduino board. It starts by initializing the Wire library and Serial communication. The loop function then iterates through all possible I2C addresses (1 to 127), sends a message to each address using Wire.beginTransmission(), and checks for an acknowledgment response using Wire.endTransmission().

If the response is 0, the device is present at that address and its address is printed to the Serial monitor. If the response is 4, an error has occurred and the address is printed to the Serial monitor. If no devices are found, the code prints “No I2C devices found“, and if any devices are found, it prints “done“. The code then waits for 5 seconds before repeating the process.

In summary, this code is a useful tool for identifying the addresses of all connected I2C devices and verifying their proper functioning.