# Source: https://learn.adafruit.com/adafruit-arduino-lesson-2-leds.md

# Arduino Lesson 2. LEDs

## Overview

In this lesson, you will learn how to change the brightness of an LED by using different values of resistor.

![](https://cdn-learn.adafruit.com/assets/assets/000/002/158/medium800/learn_arduino_overview.jpg?1396780031)

- [Next Page](https://learn.adafruit.com/adafruit-arduino-lesson-2-leds/parts.md)

## Featured Products

### Adafruit METRO 328 Fully Assembled - Arduino IDE compatible

[Adafruit METRO 328 Fully Assembled - Arduino IDE compatible](https://www.adafruit.com/product/50)
We sure love the ATmega328 here at Adafruit, and we use them&nbsp;_a lot_&nbsp;for our own projects. The processor has plenty of GPIO, Analog inputs, hardware UART SPI and I2C, timers and PWM galore - just enough for most simple projects. When we need to go small, we use a <a...></a...>

Out of Stock
[Buy Now](https://www.adafruit.com/product/50)
[Related Guides to the Product](https://learn.adafruit.com/products/50/guides)
### Diffused Red 5mm LED (25 pack)

[Diffused Red 5mm LED (25 pack)](https://www.adafruit.com/product/299)
Need some indicators? We are big fans of these diffused red LEDs, in fact we use them exclusively in our kits. They are fairly bright so they can be seen in daytime, and from any angle. They go easily into a breadboard and will add that extra zing to your project.

- Pack of 25...

In Stock
[Buy Now](https://www.adafruit.com/product/299)
[Related Guides to the Product](https://learn.adafruit.com/products/299/guides)
### Half Sized Premium Breadboard - 400 Tie Points

[Half Sized Premium Breadboard - 400 Tie Points](https://www.adafruit.com/product/64)
This is a cute, half-size breadboard with&nbsp;400 tie points, good for small projects. It's 3.25" x 2.2" / 8.3cm&nbsp;x 5.5cm&nbsp;with a standard double-strip in the middle and two power rails on both sides.&nbsp;You can pull the power rails off easily to make the breadboard as...

In Stock
[Buy Now](https://www.adafruit.com/product/64)
[Related Guides to the Product](https://learn.adafruit.com/products/64/guides)
### Premium Male/Male Jumper Wires - 40 x 6" (150mm)

[Premium Male/Male Jumper Wires - 40 x 6" (150mm)](https://www.adafruit.com/product/758)
Handy for making wire harnesses or jumpering between headers on PCB's. These premium jumper wires are 6" (150mm) long and come in a 'strip' of 40 (4 pieces of each of ten rainbow colors). They have 0.1" male header contacts on either end and fit cleanly next to each other...

In Stock
[Buy Now](https://www.adafruit.com/product/758)
[Related Guides to the Product](https://learn.adafruit.com/products/758/guides)

## Related Guides

- [LSM303 Accelerometer + Compass Breakout](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout.md)
- [Arduino Lesson 6. Digital Inputs](https://learn.adafruit.com/adafruit-arduino-lesson-6-digital-inputs.md)
- [WiFi Candy Bowl Monitor](https://learn.adafruit.com/wifi-candy-bowl.md)
- [Arduino Lesson 12. LCD Displays - Part 2](https://learn.adafruit.com/adafruit-arduino-lesson-12-lcd-displays-part-2.md)
- [Character LCDs](https://learn.adafruit.com/character-lcds.md)
- [Silicone Robo-Tentacle](https://learn.adafruit.com/silicone-robo-tentacle.md)
- [Arduino Ethernet + SD Card](https://learn.adafruit.com/arduino-ethernet-sd-card.md)
- [Arduino Lesson 15. DC Motor Reversing](https://learn.adafruit.com/adafruit-arduino-lesson-15-dc-motor-reversing.md)
- [Arduin-o-Phone](https://learn.adafruit.com/arduin-o-phone-arduino-powered-diy-cellphone.md)
- [Remote controlled door lock using a fingerprint sensor & Adafruit IO](https://learn.adafruit.com/remote-controlled-door-lock-using-a-fingerprint-sensor-and-adafruit-io.md)
- [Adafruit 4-Channel ADC Breakouts](https://learn.adafruit.com/adafruit-4-channel-adc-breakouts.md)
- [Ladyada's Learn Arduino - Lesson #2](https://learn.adafruit.com/ladyadas-learn-arduino-lesson-number-2.md)
- [Adafruit 2.8" TFT Touch Shield v2 - Capacitive or Resistive](https://learn.adafruit.com/adafruit-2-8-tft-touch-shield-v2.md)
- [Arduino Lesson 4. Eight LEDs and a Shift Register](https://learn.adafruit.com/adafruit-arduino-lesson-4-eight-leds.md)
- [2.8" TFT Touch Shield](https://learn.adafruit.com/2-8-tft-touch-shield.md)