Install Arduino IDE

Download and install the Arduino IDE from the official website.

1. Go to arduino.cc/en/software
2. Download the version for your OS (Windows / Mac / Linux)
3. Install it and open the IDE
4. Connect your Arduino UNO via USB - the IDE should detect it automatically

Wire the Circuit

Connect the LED and resistor to the Arduino on a breadboard.

1. Place the LED on the breadboard - note the longer leg is positive (+)
2. Connect the positive leg of the LED to Pin 13 on Arduino via a jumper wire
3. Connect a 220Ω resistor between the negative leg of the LED and the GND pin on Arduino

Wiring Diagram

Write the Code by opening Arduino UNO

Open Arduino IDE, create a new sketch, and type the following code:

// Blink LED - NKDevSpace Tutorial

void setup() {
  pinMode(13, OUTPUT);  // Set pin 13 as output
}

void loop() {
  digitalWrite(13, HIGH);  // Turn LED ON
  delay(1000);              // Wait 1 second
  digitalWrite(13, LOW);   // Turn LED OFF
  delay(1000);              // Wait 1 second
}

Upload & Run

1. Click the Upload button (right arrow icon) in Arduino IDE
2. Wait for "Done uploading" message at the bottom
3. Your LED should now blink ON and OFF every 1 second!

Try It Yourself - Challenges

Now that it works, try these to level up:

• Make the LED blink 3 times fast, then pause for 2 seconds
• Add a second LED on Pin 12 and alternate the blinking
• Use the Serial Monitor to print "ON" and "OFF" messages