Beginner 15 mins

1. LED Blink

The "Hello World" of electronics. In this project, you will learn how to write your first program, upload it to the Arduino board, and control a Light Emitting Diode (LED).

Hero Image Placeholder

Components Required

  • 1x Arduino UNO R3 Buy
  • 1x 5mm LED (Any Color)
  • 1x 220Ω Resistor
  • 1x Breadboard
  • 2x Jumper Wires (Male-to-Male)

Tools Required

  • Computer (Windows/Mac/Linux) To write and upload code.
  • USB Cable To connect the Arduino to your computer.

Circuit Diagram

Follow the schematic below to wire up your components on the breadboard.

Circuit Diagram / Fritzing Placeholder Add wiring diagram here.

Important Wiring Note

Make sure to connect the longer leg (anode) of the LED to Digital Pin 13 through the resistor, and the shorter leg (cathode) to GND.

Step-by-Step Instructions

1

Connect the LED

Place the LED on the breadboard. Connect a 220Ω resistor to the long leg (anode). Connect a wire from the other end of the resistor to Pin 13 on the Arduino.

2

Connect to Ground

Connect a wire from the short leg (cathode) of the LED to any of the GND pins on the Arduino board.

3

Connect to Computer

Use the USB cable to connect the Arduino to your computer. Open the Arduino IDE software.

The Code

blink.ino 
// The setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(13, OUTPUT);
}

// The loop function runs over and over again forever
void loop() {
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);              // wait for a second
  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);              // wait for a second
}

Copy this code and paste it into the Arduino IDE. Select your Arduino board and port from the Tools menu, then click the "Upload" arrow button.

Troubleshooting

  • LED not blinking?
    Check if the LED is plugged in backwards. Try flipping it around.
  • Upload Error?
    Make sure you have selected the correct Board and Port in the Arduino IDE Tools menu.

Downloads

blink_source_code.ino
circuit_diagram.pdf

Project Complete! 🎉

Great job completing your first project. Ready to add more complexity?

Next Project: Traffic Light