💡 Arduino UNO LED Blink

A simple and classic project that blinks an LED connected to pin 13 on the Arduino UNO board.
This is often called the “Hello World” of embedded systems — the first step toward mastering microcontrollers.

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🧠 Overview

This project demonstrates how to control a digital output pin on the Arduino UNO.
The LED is turned ON for one second and then OFF for one second, repeating forever.

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⚙️ Hardware Requirements

• Arduino UNO
• USB Cable (Type-B)
• Built-in LED (on pin 13) or
• External LED + 220Ω resistor

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🔌 Circuit Connection

If using an external LED:

• LED Anode (+) → Digital Pin 13
• LED Cathode (–) → GND (through a 220Ω resistor)

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🧾 Arduino Code

const int led = 13;

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

void loop() {
  digitalWrite(led, HIGH);
  delay(1000);
  digitalWrite(led, LOW);
  delay(1000);
}
🚀 How to Upload the Code
Open Arduino IDE

Copy and paste the code above

Select Tools → Board → Arduino UNO

Select the correct COM Port

Click Upload

The LED should blink every one second after successful upload.

🧰 Software Tools
Arduino IDE (version 2.0 or later)

GitHub Desktop (optional for version control)

📸 Output
🔹 LED turns ON for 1 second
🔹 LED turns OFF for 1 second
🔁 Repeats continuously