📌 1. What Is Arduino?

Arduino is an open-source electronics platform used to build:

• Robots
• Smart home systems
• IoT devices
• Sensors
• Automation tools
• Learning electronic circuits

It consists of:

• A microcontroller board (like Arduino Uno)
• A programming software (Arduino IDE)
• A wide ecosystem of sensors, modules, motors, LEDs, etc.

📌 2. What You Need to Start

Mandatory:

• Arduino Uno board
• USB cable (type A to type B)
• LED + 220Ω resistor
• Breadboard
• Jumper wires

Optional but very useful:

• Potentiometer
• Temperature sensor (LM35 or DHT11)
• Ultrasonic sensor HC-SR04
• Servo motor
• Buzzer
• LCD display 16x2

You can easily order a starter kit on Amazon or AliExpress.

📌 3. Installing the Arduino IDE

Step 1: Download Arduino IDE

👉 https://www.arduino.cc/en/software

Step 2: Install it

Windows / Mac / Linux supported

Step 3: Connect your Arduino board with USB

Your computer will install drivers automatically.

Step 4: Select the board

Tools → Board → Arduino Uno

Step 5: Select the COM port

Tools → Port → COMX (Arduino Uno)

📌 4. Understanding the Arduino IDE

Basic program structure:

void setup() {
  // runs once
}

void loop() {
  // runs forever
}

• setup() initializes pins, communication…
• loop() is the program that runs repeatedly (like a continuous cycle)

📌 5. Your First Project: Blink an LED

Wiring

Code: Blink LED

void setup() {
  pinMode(13, OUTPUT);  // Use pin 13
}

void loop() {
  digitalWrite(13, HIGH); // LED ON
  delay(1000);            // wait 1 sec
  digitalWrite(13, LOW);  // LED OFF
  delay(1000);
}

Upload → The LED blinks every second.
Congratulations! You executed your first microcontroller program!

📌 6. Project 2: Control LED with a Button

Wiring

Code

int button = 2;
int led = 13;

void setup() {
  pinMode(button, INPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  int state = digitalRead(button);

  if (state == HIGH) {
    digitalWrite(led, HIGH);
  } else {
    digitalWrite(led, LOW);
  }
}

Now the LED turns ON when you press the button.

📌 7. Project 3: Read Analog Values (Potentiometer)

This teaches you analog signals and analogRead().

Wiring

Code

int pot = A0;
int value;

void setup() {
  Serial.begin(9600);
}

void loop() {
  value = analogRead(pot);   // read 0–1023
  Serial.println(value);
  delay(200);
}

Open Serial Monitor → you will see the values change.

📌 8. Project 4: Control LED Brightness (PWM)

Using analogWrite() on a PWM pin (marked with ~).

Wiring: LED to pin 9

Code:

int led = 9;
int brightness = 0;

void setup() {
  pinMode(led, OUTPUT);
}

void loop() {
  for (brightness = 0; brightness <= 255; brightness++) {
    analogWrite(led, brightness); 
    delay(10);
  }

  for (brightness = 255; brightness >= 0; brightness--) {
    analogWrite(led, brightness);
    delay(10);
  }
}

LED will fade in and out smoothly.

📌 9. Project 5: Ultrasonic Distance Sensor (HC-SR04)

Purpose: measure distance (robotics, security, parking system)

Wiring

Code

#define trig 9
#define echo 10

void setup() {
  Serial.begin(9600);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
}

void loop() {
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  long duration = pulseIn(echo, HIGH);
  long distance = duration * 0.034 / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(300);
}

Now you have a basic radar distance measurement system.

📌 10. Project 6: Servo Motor Control

Used in:

• Robotics
• Arm movement
• Car steering

Wiring

Code

#include <Servo.h>

Servo motor;

void setup() {
  motor.attach(9);
}

void loop() {
  motor.write(0);
  delay(1000);
  motor.write(90);
  delay(1000);
  motor.write(180);
  delay(1000);
}

📌 11. Project 7: Temperature & Humidity Sensor (DHT11)

Wiring

Code

#include "DHT.h"

#define DHTPIN 2
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  dht.begin();
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  Serial.print("Temp: "); Serial.print(t); Serial.println("°C");
  Serial.print("Hum: ");  Serial.print(h); Serial.println("%");
  delay(1000);
}

You now have a mini-weather station.

📌 12. Summary of Essential Arduino Skills

By completing these lessons, you’ve learned:

You now have enough knowledge to build real-world Arduino projects.

📌 13. What You Can Build Next (Advanced Projects)

Next-level ideas:

• Smart home system (lights + gas sensor + relay)
• Robot car with obstacle avoidance
• Fingerprint door lock
• IoT system with ESP8266 (WiFi)
• Automated irrigation system
• Motion detection alarm with PIR sensor
• RFID access security system