CIPAD: Leçon 13: Branchements des écrans lcd 16x2 standards VS les écrans LCD I2C

Introduction

This tutorial will guide you through the process of connecting standard 16x2 LCD screens versus I2C LCD screens to an Arduino. Understanding these connections is crucial for beginners in Arduino programming, especially when working with multiple displays.

Step 1: Understanding LCD Types

• Standard 16x2 LCD: This type has 16 columns and 2 rows. It requires more wiring since each pin must be connected directly to the Arduino.
• I2C LCD: This is an advanced version that uses an I2C interface, simplifying the connection process to just two wires (SDA and SCL) plus power and ground.

Practical Advice

• Choose the type of LCD based on your project needs. If you're working on a compact project, I2C is preferred due to its simplicity.

Step 2: Wiring the Standard 16x2 LCD

To connect a standard 16x2 LCD to your Arduino, follow these steps:

1. Identify Pins: A standard 16x2 LCD has several pins, typically:
   • VSS: Ground
   • VDD: Power (+5V)
   • V0: Contrast
   • RS: Register Select
   • RW: Read/Write
   • E: Enable
   • D0-D7: Data pins (8 in total)
2. Connect Pins: Use jumper wires to connect the LCD pins to the corresponding Arduino pins. A common setup is:
   • VSS to Ground
   • VDD to 5V
   • V0 to a potentiometer for contrast adjustment
   • RS to pin 12
   • RW to Ground
   • E to pin 11
   • D4 to pin 5
   • D5 to pin 4
   • D6 to pin 3
   • D7 to pin 2

Common Pitfalls

• Ensure that the contrast pin is connected properly to avoid a blank screen.
• Double-check pin connections to prevent programming errors.

Step 3: Wiring the I2C LCD

Connecting an I2C LCD is straightforward:

1. Identify Pins: An I2C LCD typically has four pins:
   • VCC: Power (+5V)
   • GND: Ground
   • SDA: Data line
   • SCL: Clock line
2. Connect Pins: Use jumper wires to connect:
   • VCC to 5V
   • GND to Ground
   • SDA to pin A4 (for most Arduino boards)
   • SCL to pin A5 (for most Arduino boards)

Practical Advice

• With I2C, you can connect multiple devices on the same bus, making it ideal for projects with several sensors or displays.

Step 4: Programming the Arduino

Regardless of the LCD type, you will need to include specific libraries in your Arduino IDE:

• For standard LCDs, use the LiquidCrystal library.
• For I2C displays, use the LiquidCrystal_I2C library.

Example Code for Standard 16x2 LCD

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  lcd.print("Hello, World!");
}

void loop() {
  // Your code here
}

Example Code for I2C LCD

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

LiquidCrystal_I2C lcd(0x27, 16, 2); // Adjust address as needed

void setup() {
  lcd.begin();
  lcd.print("Hello, World!");
}

void loop() {
  // Your code here
}

Conclusion

By following this tutorial, you have learned how to connect both standard and I2C LCD screens to an Arduino and how to write the basic code to display text. Depending on your project requirements, choose the appropriate LCD type and enjoy exploring the capabilities of your Arduino with these displays. As a next step, consider experimenting with additional libraries and functionalities, such as displaying sensor data or creating interactive menus.