Blog

LCD1602 Parallel LCD Display with Blue Backlight

Posted by

Ekostra Electronics

On April 5, 2025

Comments Off

LCD1602 Parallel LCD Display with Blue Backlight

16×2 Character Display for Arduino and Microcontroller Projects

Introduction

The LCD1602 display module is a classic parallel interface character LCD featuring a 16×2 character display with blue backlight. These displays use the HD44780 controller or compatible chips and are widely supported in the maker community.

Key Features

🔵 Blue Backlight

High-contrast display with adjustable blue backlight

🔢 Character Grid

16 columns × 2 rows (32 characters total)

⚙️ Parallel Interface

4-bit or 8-bit parallel communication

💾 Custom Characters

Supports 8 user-defined characters

Technical Specifications

Display Type	Character LCD
Display Format	16 columns × 2 rows
Controller	HD44780 or compatible
Interface	Parallel (4-bit or 8-bit)
Operating Voltage	5V (typically)
Backlight	Blue with adjustable brightness

Pin Configuration

Pin	Symbol	Description	Arduino Connection
1	VSS	Ground	GND
2	VDD	Power (+5V)	5V
3	VO	Contrast adjustment	Potentiometer
4	RS	Register Select	Digital Pin
5	RW	Read/Write	GND (for write only)
6	E	Enable	Digital Pin
7-14	DB0-DB7	Data Bus	Digital Pins (4-bit: DB4-DB7)
15	A	Backlight Anode (+)	5V via resistor
16	K	Backlight Cathode (-)	GND

Note: For 4-bit mode, only DB4-DB7 need to be connected

Wiring with Arduino

4-Bit Mode Connection

// Typical 4-bit connections:
// LCD RS → Arduino D12
// LCD E → Arduino D11
// LCD D4 → Arduino D5
// LCD D5 → Arduino D4
// LCD D6 → Arduino D3
// LCD D7 → Arduino D2
// LCD R/W → GND
// LCD VSS → GND
// LCD VDD → 5V
// LCD VO → Potentiometer center pin
// LCD A → 5V (with resistor)
// LCD K → GND

// Typical 4-bit connections:

// LCD RS → Arduino D12

// LCD E → Arduino D11

// LCD D4 → Arduino D5

// LCD D5 → Arduino D4

// LCD D6 → Arduino D3

// LCD D7 → Arduino D2

// LCD R/W → GND

// LCD VSS → GND

// LCD VDD → 5V

// LCD VO → Potentiometer center pin

// LCD A → 5V (with resistor)

// LCD K → GND

Contrast Adjustment

Connect pin 3 (VO) to a 10K potentiometer between VCC and GND for contrast control.

Arduino Library Setup

Install the LiquidCrystal library (included with Arduino IDE)
Include the library in your sketch:

Arduino

#include <LiquidCrystal.h>

1

#include <LiquidCrystal.h>
Initialize the display with your pin configuration:

// Initialize with (RS, E, D4, D5, D6, D7)
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

1 2	// Initialize with (RS, E, D4, D5, D6, D7) LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

Basic Display Example

#include <LiquidCrystal.h>

// Initialize the library with pin numbers
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // Set up the LCD's number of columns and rows
  lcd.begin(16, 2);
  
  // Print a message to the LCD
  lcd.print("Hello, World!");
}

void loop() {
  // Set the cursor to column 0, line 1
  lcd.setCursor(0, 1);
  
  // Print the number of seconds since reset
  lcd.print(millis() / 1000);
}

#include <LiquidCrystal.h>

// Initialize the library with pin numbers

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {

// Set up the LCD's number of columns and rows

lcd.begin(16, 2);

// Print a message to the LCD

lcd.print("Hello, World!");

}

void loop() {

// Set the cursor to column 0, line 1

lcd.setCursor(0, 1);

// Print the number of seconds since reset

lcd.print(millis() / 1000);

}

Advanced Features

Custom Characters

// Create custom character
byte heart[8] = {
  0b00000,
  0b01010,
  0b11111,
  0b11111,
  0b01110,
  0b00100,
  0b00000,
  0b00000
};

void setup() {
  lcd.createChar(0, heart);
  lcd.write(byte(0));
}

// Create custom character

byte heart[8] = {

0b00000,

0b01010,

0b11111,

0b01110,

0b00100,

0b00000,

0b00000

};

void setup() {

lcd.createChar(0, heart);

lcd.write(byte(0));

}

Scrolling Text

void scrollText(String message) {
  for (int i=0; i < message.length(); i++) {
    lcd.scrollDisplayLeft();
    lcd.print(message[i]);
    delay(300);
  }
}

void scrollText(String message) {

for (int i=0; i < message.length(); i++) {

lcd.scrollDisplayLeft();

lcd.print(message[i]);

delay(300);

}

Backlight Control

// Connect backlight through transistor
// or MOSFET for PWM control
void setBacklight(int brightness) {
  analogWrite(backlightPin, brightness);
}

// Connect backlight through transistor

// or MOSFET for PWM control

void setBacklight(int brightness) {

analogWrite(backlightPin, brightness);

}

Multiple Displays

// Use different enable pins
LiquidCrystal lcd1(12, 11, 5, 4, 3, 2);
LiquidCrystal lcd2(12, 10, 5, 4, 3, 2);

// Use different enable pins

LiquidCrystal lcd1(12, 11, 5, 4, 3, 2);

LiquidCrystal lcd2(12, 10, 5, 4, 3, 2);

Troubleshooting

Blank Display

Adjust contrast potentiometer
Check power connections (5V and GND)
Verify backlight is connected properly

Garbled Characters

Check data pin connections
Ensure proper initialization (lcd.begin(16, 2))
Verify RW pin is grounded

Missing Characters

Check timing (add small delays if needed)
Verify correct column/row in setCursor()
Ensure proper contrast setting

Hotline 24/7

LCD1602 Parallel LCD Display with Blue Backlight

Introduction

Key Features

🔵 Blue Backlight

🔢 Character Grid

⚙️ Parallel Interface

💾 Custom Characters

Technical Specifications

Pin Configuration

Wiring with Arduino

4-Bit Mode Connection

Contrast Adjustment

Arduino Library Setup

Basic Display Example

Advanced Features

Custom Characters

Scrolling Text

Backlight Control

Multiple Displays

Troubleshooting

Blank Display

Garbled Characters

Missing Characters

Project Ideas

Weather Station

Menu System

Data Logger

Related Posts

Get to Know Us

Shop

Useful Links

Subscribe Newsletter

Safety Payments