How to use LCD 1602 I2C and show Joystick values with Arduino

What is an LCD 1602?

The LCD 1602 is a popular display module that can show 2 lines of 16 characters. It’s great for displaying values, messages, or sensor data in embedded and Arduino projects.

Without I2C, it requires up to 12 pins, which is not ideal. That’s where I2C comes in.

What is I2C?

I2C (Inter-Integrated Circuit) is a communication protocol that lets microcontrollers and peripherals (like LCDs) communicate using just two wires:

• SDA (data)
• SCL (clock)

This reduces the number of Arduino pins used, making your project cleaner and more scalable.

Most I2C LCD modules have an I2C backpack with a default address 0x27.

Hardware Used

• Arduino UNO
• LCD 1602 with I2C backpack
• Analog Joystick
• Breadboard + Jumper wires

Connections:

Arduino Code Explanation

Here's the optimized code that avoids flickering and updates only when needed:

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

LiquidCrystal_I2C lcd(0x27, 16, 2);
int lastValue = -1;

void setup() {
  pinMode(A0, INPUT);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 1);
  lcd.print("soslab.net");
}

void loop() {
  int readJoy = analogRead(A0);
  if (abs(readJoy - lastValue) > 2) {
    lcd.setCursor(0, 0);
    lcd.print("Value:       ");
    lcd.setCursor(7, 0);
    lcd.print(readJoy);
    lastValue = readJoy;
  }
  delay(10);
}

Fixing LCD Flickering

When working with analog inputs like joysticks, values may fluctuate slightly even without movement.
To avoid flickering and unnecessary redraws, we added:

if (abs(readJoy - lastValue) > 2)

This creates a small "dead zone" that ignores minor noise and updates the screen only when the joystick actually moves.

Why This Matters

• 🧹 Cleaner UI: No more screen blinking or ghost values.
• ⚡ Efficient: Less screen redraw, better performance.
• 🧠 Scalable: This method can be reused for other sensors and LCD displays.

Summary

In this tutorial, we:

• Connected a 1602 LCD with I2C to an Arduino
• Read joystick values via analog pin A0
• Optimized display updates to reduce flickering
• Displayed real-time values smoothly

This is a great beginner project to learn I2C, analog input handling, and how to write efficient Arduino code.