A Simple Two-Wire LCD Programming With Arduino Uno

In this example, I use PCF8574T module that designed for character LCD interfacing. We can solder this module directly with the LCD. However I put either PCF8574T module and the LCD on a single breadboard.

Running program

 The connection between the Arduino Uno and the two-wire display module uses only two communication wires, and two power supply pins.

1. GND
2. +5V (VDD)
3. SCL connects to Arduino pin A5
4. SDA connects to Arduino pin A4

It need the LiquidCrystal_I2C.h file that we need to install it. The program will show a simple text display with a little delay between each characters.

//Two-Wire Library
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
 
//LCD Setting
LiquidCrystal_I2C lcd(0x27,16,2);
 
void setup(){
  //Initialize the LCD
  lcd.init();
  //Turn on the back light
  lcd.backlight();
  //Blink the cursor
  lcd.blink();
 
  lcdShow("AKI Technical");
  lcd.setCursor(0,1);
  lcdShow("YouTube Channel");
}
 
void lcdShow(char *txt){
  while(*txt){
    lcd.print(*txt++);
    delay(500);
  }
}
 
void loop(){
 
}
 

 Click here to download its source file.

We can use the ATMega32 to control a 3-Wire SPI LCD module (SN74HC595N chip).