1. What Are Additions in Arduino?

Additions refer to any external components or modules that enhance the Arduino's ability to interact with the environment or perform specific tasks.

They include:

• Sensors
• Actuators
• Displays
• Communication modules
• Shields
• Libraries
• Expansion boards

🔹 2. Common Additions in Arduino Projects

✅ A. Sensors (Input Devices)

Used to sense physical parameters:

✅ B. Actuators (Output Devices)

Used to perform actions based on Arduino outputs:

✅ C. Displays

To display data from Arduino:

✅ D. Communication Modules

For wireless or wired communication:

✅ E. Shields

Pre-made boards that stack on top of Arduino for plug-and-play functionality:

✅ F. Expansion Boards

Other microcontroller-based boards to extend Arduino:

• NodeMCU (WiFi)
• ESP32 (WiFi + Bluetooth)
• Arduino Mega (more I/O pins)

✅ G. Libraries (Software Additions)

• Help interact with sensors, displays, and modules
• Examples:DHT.h,Servo.h,Wire.h,LiquidCrystal.h

🔹 3. Real-World Example: Adding DHT11 Sensor and Display

Components Added:

• DHT11 Sensor
• 16x2 LCD Display

Function: Read temperature & humidity, display on LCD.

#include <DHT.h>

#include <LiquidCrystal.h>

#define DHTPIN 2

#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {

  lcd.begin(16, 2);

  dht.begin();

}

void loop() {

  float h = dht.readHumidity();

  float t = dht.readTemperature();

  lcd.setCursor(0, 0);

  lcd.print("Temp: ");

  lcd.print(t);

  lcd.print(" C");

  lcd.setCursor(0, 1);

  lcd.print("Humidity: ");

  lcd.print(h);

  lcd.print("%");

  delay(2000);

}

🧾 Summary Table: Additions in Arduino