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LCD Display (I2C) | NexaLearn IoT Lab | NexaLearn

Displays25 دقيقة

LCD Display (I2C)

Printing clear messages using only 4 wires.

Lesson Content

Traditional LCD screens require 6 data wires, consuming Arduino's ports. So we use an I2C module soldered to the back of the screen, which reduces the wires to just 4 (2 power, and 2 data wires: SDA and SCL). The I2C protocol allows multiple devices to share the same two wires as long as each device has a unique 'address'.

Components Needed

Arduino Unoشاشة LCD 16x2 مع موديول I2C

Wiring Notes

VCC to 5V, GND to GND. SDA wire connects to pin A4 on the Uno, and SCL to pin A5.

Code Example

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2); // العنوان غالباً 0x27 أو 0x3F

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0); // العمود 0، الصف 0
  lcd.print("Darhous IoT Lab");
}
void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis() / 1000);
  delay(1000);
}

Common Mistakes

Screen is fully lit or shows black squares but no text? Try turning the small brass screw (Potentiometer) on the back of the module with a screwdriver to adjust the contrast.

Next Lesson

Relay & 220V Control