Interface an LCD with an Arduino

You can easily interface a liquid crystal display (LCD) with an Arduino to provide a user interface.

Liquid crystal displays (LCDs) are a commonly used to display data in devices such as calculators, microwave ovens, and many other electronic devices..

In this tutorial, I will show you how to use a 16x2 LCD with an Arduino. The 16x2 LCD used in this experiment has a total of 16 pins. As shown in the table below, eight of the pins are data lines (pins 7-14), two are for power and ground (pins 1 and 16), three are used to control the operation of LCD (pins 4-6), and one is used to adjust the LCD screen brightness (pin 3). The remaining two pins (15 and 16) power the backlight.The details of the LCD terminals are as follows:

Experiment 1

In this experiment, we will interface a 16x2 LCD with Arduino Mega 2560 and display some text on the LCD.

Hardware Required

• 1 x 16x2 LCD
  
• 1 x Arduino Mega 2560
  
• 1x 5k ohm potentiometer
  
• female connectors
  
• jumper wires
  

Wiring Diagram

In this circuit, the LCD terminals are connected to the Arduino pins according to the table below. Connect the outer two terminals of the potentiometer to 5V and ground, and the middle terminal to pin 3 of LCD. Rotating the potentiometer controls the brightness of the LCD backlight. The LCD back light pins are connected to 5V and ground as shown in the diagram below:

DB4----->pin4

DB5----->pin5

DB6----->pin6

DB7----->pin7

RS-----> pin8

EN-----> pin9

Code

#include "LiquidCrystal.h"

// initialize the library by providing the nuber of pins to it
LiquidCrystal lcd(8,9,4,5,6,7);

void setup() {
lcd.begin(16,2);

// set cursor position to start of first line on the LCD
lcd.setCursor(0,0);
//text to print
lcd.print("   16x2 LCD");
// set cusor position to start of next line
lcd.setCursor(0,1);
lcd.print("   DISPLAY");
}
void loop()
{}

Interface_LCD_Arduino.zip

Experiment 2

In this experiment, we will display the 'value of' counter in the Arduino. It will count the number of seconds, up to a value of 100.

Hardware Required

Wiring Diagram

The circuit for this experiment is the same as for Experiment #1.

Code

#include "LiquidCrystal.h"

// initialize the library by providing the nuber of pins to it
LiquidCrystal lcd(8,9,4,5,6,7);

void setup() {
lcd.begin(16,2);

// set cursor position to start of first line on the LCD
lcd.setCursor(0,0);
//text to print
lcd.print("    COUNTER");
delay(100);

int a=0;
lcd.setCursor(0,1);
lcd.print("       ");
lcd.print(a);
while(a<=100)
{
  a=a+1;
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print("       ");
  lcd.print(a);
}
}
void loop()
{
  lcd.clear();
}

Interface_an_LCD.zip

Videos

Give this project a try for yourself! Get the BOM.