1602 16×2 HD44780 LCD Display with Soldered I2C Module – Support Documentation

The 1602 16×2 HD44780 LCD Display with Soldered I2C Module simplifies the process of integrating a character LCD into your Arduino projects. By utilising the I2C interface, this module reduces the number of required microcontroller pins, making it ideal for applications where pin availability is limited.

Key Features

• Display: 16 characters x 2 lines
• Controller: HD44780
• Interface: I2C (via PCF8574 I/O expander)
• Operating Voltage: 5V DC
• Backlight: Blue with white characters
• Adjustable contrast via onboard potentiometer
• Default I2C Address: 0x27 or 0x3F (dependent on module)
• Compact size: approximately 80mm x 36mm

Pinout Configuration

The I2C module attached to the LCD provides a 4-pin interface:

Wiring to Arduino

Connect the LCD module to your Arduino as follows:

Note: For other Arduino boards, SDA and SCL pins may differ. Refer to your board’s documentation.

Library Installation

To use the LCD with Arduino, install the LiquidCrystal_I2C library:

1. Open the Arduino IDE.
2. Navigate to Sketch > Include Library > Manage Libraries…
3. In the Library Manager, search for LiquidCrystal_I2C.
4. Install the library by Frank de Brabander.

Sample Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 or 0x3F for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  lcd.init();                      // Initialize the LCD
  lcd.backlight();                 // Turn on the backlight
  lcd.setCursor(0, 0);             // Set cursor to column 0, row 0
  lcd.print("Hello, World!");      // Print message
}

void loop() {
  // Add your code here
}

Note: If the display does not show text, try changing the I2C address from 0x27 to 0x3F in the code.

Adjusting Contrast

Use the onboard potentiometer (blue square component) to adjust the display contrast:

• Turn the potentiometer clockwise or counter-clockwise until the characters are clearly visible.

Changing I2C Address

The I2C address can be changed by modifying the address selection jumpers (A0, A1, A2) on the I2C module:

• Each jumper corresponds to a bit in the address.
• Bridging a jumper sets the corresponding bit to 0; leaving it open sets it to 1.
• Refer to the PCF8574 datasheet for detailed address configuration.

Common Issues and Troubleshooting

• Blank Display: Adjust the contrast potentiometer; ensure correct wiring and power supply.
• Incorrect Characters: Verify the I2C address in the code matches the module’s address.
• No Backlight: Check the backlight control jumper or code settings; ensure the backlight is enabled in the code.

Applications

• Displaying sensor readings (e.g., temperature, humidity)
• Creating user interfaces for Arduino projects
• Menu systems for embedded applications
• Educational purposes and prototyping