I2C LCD Code Generator

What Is an Arduino I2C LCD and How to Use It?

An I2C LCD is a standard 16x2 or 20x4 character display with a PCF8574 I2C backpack soldered to the back. A normal LCD needs six or more digital pins, while an I2C LCD works with just two data pins (SDA and SCL). This tool generates a ready-to-run LiquidCrystal_I2C sketch from your size, I2C address and text. Everything runs in your browser.

Wiring (Arduino Uno)

• VCC → 5V
• GND → GND
• SDA → A4
• SCL → A5

On the Arduino Mega, SDA is pin 20 and SCL is pin 21.

Can't Find the I2C Address? (I2C Scanner)

If you do not know your module's address, upload the scanner sketch below and open the Serial Monitor (9600 baud). Enter the address it reports into the I2C Address box above.

#include <Wire.h>
void setup() {
  Wire.begin();
  Serial.begin(9600);
  Serial.println("I2C scanner started...");
  for (byte a = 1; a < 127; a++) {
    Wire.beginTransmission(a);
    if (Wire.endTransmission() == 0) {
      Serial.print("Device found: 0x");
      Serial.println(a, HEX);
    }
  }
}
void loop() {}