Blinking an LED with Arduino

Things You’ll Need

• Arduino UNO board
• 1 x LED (any color)
• 1 x 220Ω resistor
• Breadboard
• Jumper wires
• USB cable to connect Arduino to your computer

Step 1: Circuit Connections

The LED has two legs: long leg = anode (+), short leg = cathode (–).

• Connect the anode (long leg) to pin 13 on the Arduino through a 220Ω resistor.
• Connect the cathode (short leg) to the Arduino’s GND.

Step 2: Building the Circuit

1. Place the LED on the breadboard.
2. Connect a 220Ω resistor to the long leg of the LED.
3. Use a jumper wire to connect the other side of the resistor to digital pin 13.
4. Connect the short leg of the LED directly to GND on the Arduino.

Step 3: Write the Code

Let’s now write the code for the Arduino sketch. Launch the Arduino IDE and enter:

Copy
void setup() {
  pinMode(13, 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
}