SENSORS/ACTUATORS

INTERNET OF THING (IoT)

Arduino Nano - Ethernet

Arduino Nano - Web Server

Arduino Nano - LCD

This tutorial instructs you how to use LCD display with Arduino Nano, how to program for Arduino Nano to display text, special characters on LCD.

Hardware Preparation

1	×	Arduino Nano
1	×	USB A to Mini-B USB cable
1	×	LCD I2C
1	×	Jumper Wires
1	×	Breadboard
1	×	(Recommended) Screw Terminal Expansion Board for Arduino Nano
1	×	(Recommended) Breakout Expansion Board for Arduino Nano

Or you can buy the following sensor kits:

1	×	DIYables Sensor Kit (30 sensors/displays)
1	×	DIYables Sensor Kit (18 sensors/displays)

Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.

Overview of LCD I2C 16x2

LCD I2C is made up of a standard LCD, an I2C module and a potentiometer. It is highly recommended to use the LCD I2C instead of standard LCD. That is because using the LCD I2C make the wiring much easier.

The LCD Pinout

The LCD I2C uses the I2C interface to connect to Arduino Nano. It has four pins:

The GND pin needs to be connected to ground (0V).
The VCC pin is the power supply for the LCD and must be connected to VCC (5V).
The SDA pin is the I2C data signal.
The SCL pin is the I2C clock signal.

LCD Coordinate

The LCD I2C 16x2 has 16 columns and 2 rows, with the columns and rows being numbered starting from 0.

Wiring Diagram

This image is created using Fritzing. Click to enlarge image

LCD I2C module	Arduino Nano
Vin	5V
GND	GND
SDA	A4
SCL	A5

How To Program For LCD I2C

The LiquidCrystal_I2C library needs to be included in order to use the LCD.

Set up the LCD:

The LCD must be set up properly for it to work correctly.

Write to the LCD:

Writing to the LCD is easy thanks to the LiquidCrystal_I2C library.

#include <LiquidCrystal_I2C.h> // Library for LCD

Create a LiquidCrystal_I2C object with an I2C address, the number of columns, and the number of rows specified.

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows

Start up the LCD.

lcd.init(); //initialize the lcd lcd.backlight(); //open the backlight

Go to the column and row indicated by column_index and row_index respectively.

lcd.setCursor(column_index, row_index);

Display a message on the LCD.

lcd.print("Hello World!");

Explore the possibilities of what can be achieved with LCD by looking at the "Do More with LCD" section.

※ NOTE THAT:

The address of the LCD may differ depending on the manufacturer. For our code, we used 0x27 as specified by DIYables.

Arduino Nano Code

#include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows void setup() { lcd.init(); // Initialize the LCD I2C display lcd.backlight(); lcd.setCursor(3, 0); // move cursor to (3, 0) lcd.print("DIYables"); // print message at (3, 0) lcd.setCursor(0, 1); // move cursor to (0, 1) lcd.print("www.diyables.io"); // print message at (0, 1) } void loop() { }

Detailed Instructions

Click to the Libraries icon on the left bar of the Arduino IDE.
Search for "LiquidCrystal I2C" and locate the LiquidCrystal_I2C library created by Frank de Brabander.
Then, click the Install button to add the library.

Copy the code and open it with the Arduino IDE.
Click the Upload button in the IDE to send the code to the Arduino Nano.
Check the LCD for the result.

Experiment with altering the text and its location.

Guide for Choosing an LCD I2C Display

There are many types of LCD I2C displays available, mainly differing in background color and the shape of the I2C interface module.

Regarding color, these displays usually come in two background colors: green and blue.

For the shape of the I2C interface module, consider two main aspects:

Potentiometer size: This includes options for thin and thick potentiometers.

Thick potentiometer: Easier to adjust but takes up more space.
Thin potentiometer: More compact and saves space due to its smaller height.

I2C selection jumper:

With jumper: Allows switching between two I2C addresses, useful when your code uses two LCD displays simultaneously. However, it can cause confusion with I2C addresses when only one LCD is used and it also requires more space.
Without jumper: Has a fixed I2C address and is very convenient when your code uses just one LCD display. Since most applications use only one LCD, this type is highly recommended.

Video Tutorial

Do More with LCD

Custom Character

lcd.print() only works with ASCII characters. To display a special character or symbol (e.g. heart, angry bird), you must use the character generator.

An LCD 16x2 can show up to 32 characters. Each character is made up of 40 pixels, which are arranged in 8 rows and 5 columns.

The character generator creates a character that is 40 pixels in size. To use it, simply follow these steps:

Click on each pixel to select/deselect

Copy below custom character code

Replace the customChar[8] in the below code

#include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows byte customChar[8] = { 0b00000, 0b01010, 0b11111, 0b11111, 0b01110, 0b00100, 0b00000, 0b00000 }; void setup() { lcd.init(); // Initialize the LCD I2C display lcd.backlight(); lcd.createChar(0, customChar); // create a new custom character lcd.setCursor(2, 0); // move cursor to (2, 0) lcd.write((byte)0); // print the custom char at (2, 0) } void loop() { }

The LCD showed the result. The result was displayed on the LCD.

Multiple custom characters

We are able to make a maximum of 8 custom characters, numbered from 0 to 7. The example below shows how to create and display three of them.

#include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows byte customChar0[8] = { 0b00000, 0b01010, 0b11111, 0b11111, 0b01110, 0b00100, 0b00000, 0b00000 }; byte customChar1[8] = { 0b00100, 0b01110, 0b11111, 0b00100, 0b00100, 0b00100, 0b00100, 0b00100 }; byte customChar2[8] = { 0b00100, 0b00100, 0b00100, 0b00100, 0b00100, 0b11111, 0b01110, 0b00100 }; void setup() { lcd.init(); // Initialize the LCD I2C display lcd.backlight(); lcd.createChar(0, customChar0); // create a new custom character (index 0) lcd.createChar(1, customChar1); // create a new custom character (index 1) lcd.createChar(2, customChar2); // create a new custom character (index 2) lcd.setCursor(2, 0); // move cursor to (2, 0) lcd.write((byte)0); // print the custom char 0 at (2, 0) lcd.setCursor(4, 0); // move cursor to (4, 0) lcd.write((byte)1); // print the custom char 1 at (4, 0) lcd.setCursor(6, 0); // move cursor to (6, 0) lcd.write((byte)2); // print the custom char 2 at (6, 0) } void loop() { }

The outcome displayed on the LCD is: . The result that appears on the LCD is:

Summary: how to use custom character on LCD

Employ the character generator to generate binary code for your custom character.
Copy the binary code generated in the previous step.

byte customChar[8] = { 0b00000, 0b01010, 0b11111, 0b11111, 0b01110, 0b00100, 0b00000, 0b00000 };

Assign a custom character to an index value ranging from 0 to 7 inside the setup() function.

lcd.createChar(index, customChar);

Print the custom character on the LCD at any time, either in the setup() or loop() function.

lcd.setCursor(column, row); // move cursor to a desired position lcd.write((byte)index); // print the custom char at the desired position

Other functions

Print "Hello World"

Insert the following functions into the loop() function, one at a time, with a delay of 5000 milliseconds after each:

Clear the LCD screen
Print "Hello World"

lcd.clear();

Screen
Position the cursor at the top left corner of the LCD display.

lcd.home();

Position the cursor at a certain column and row.

lcd.setCursor(column, row);

Show the LCD cursor on the screen.

lcd.cursor();

Makes the LCD cursor invisible.

lcd.noCursor();

Show the LCD cursor blinking.

lcd.blink()

Disable the blinking of the LCD cursor.

lcd.noBlink()

Additionally, you can find information at LiquidCrystal Library Reference

Challenge Yourself

Try using an LCD for one of these projects:

Sending text from a computer (via Serial Monitor) and displaying it on the LCD. Hint: See How to send data from PC to Arduino
Showing the key pressed on the keypad on the LCD. Hint: Check out Arduino Nano - Keypad

Troubleshooting on LCD I2C

Rotate the potentiometer on the back of the LCD to adjust its contrast.
Depending on the manufacturer, the I2C address of the LCD may be different. Generally, the default I2C address of the LCD is either 0x27 or 0x3F. Try both these values. If you are still unsuccessful, run the code below to find the I2C address.

// I2C address scanner program #include <Wire.h> void setup() { Wire.begin(); Serial.begin(9600); Serial.println("I2C 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"); else Serial.println("done"); delay(5000); // wait 5 seconds for next scan }

The output displayed on the Serial Monitor is: . The outcome that appears on the Serial Monitor is:

COM6

Send

Scanning... I2C device found at address 0x3F ! done Scanning... I2C device found at address 0x3F ! done

Autoscroll Show timestamp

Clear output

9600 baud

Newline

Learn More

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