# Arduino Lesson 4. Eight LEDs and a Shift Register ## Overview In this lesson, you will learn how to use eight large red LEDs with an Arduino without needing to give up 8 output pins! ![](https://cdn-learn.adafruit.com/assets/assets/000/002/101/medium800/learn_arduino_breadboard.jpg?1396779268) Although you could wire up eight LEDs each with a resistor to an Arduino pin (like we did for an RGB LED in Lesson 2) you would rapidly start to run out of pins on your Arduino. If you don't have a lot of stuff connected to your 'duino it's OK to do so - but often times we want buttons, sensors, servos, etc and before you know it you've got no pins left. So, instead of doing that, you are going to use a chip called the **74HC595 Serial to Parallel Converter**. This chip has eight outputs (perfect) and three inputs that you use to feed data into it a bit at a time. This chip makes it a little slower to drive the LEDs (you can only change the LEDs about 500,000 times a second instead of 8,000,000 a second) but it's still really really fast, way faster than humans can detect, so it's worth it! - [Next Page](https://learn.adafruit.com/adafruit-arduino-lesson-4-eight-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 _a lot_ 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. 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In Stock [Buy Now](https://www.adafruit.com/product/64) [Related Guides to the Product](https://learn.adafruit.com/products/64/guides) ## Related Guides - [74HC595 Shift Register](https://learn.adafruit.com/74hc595.md) - [LED Lightbox](https://learn.adafruit.com/led-lightbox.md) - [Multi-tasking the Arduino - Part 1](https://learn.adafruit.com/multi-tasking-the-arduino-part-1.md) - [1,500 NeoPixel LED Curtain with Raspberry Pi and Fadecandy](https://learn.adafruit.com/1500-neopixel-led-curtain-with-raspberry-pi-fadecandy.md) - [Adafruit IO Basics: NeoPixel Controller](https://learn.adafruit.com/adafruit-io-basics-neopixel-controller.md) - [Adafruit Data Logger Shield](https://learn.adafruit.com/adafruit-data-logger-shield.md) - [Light Meter](https://learn.adafruit.com/light-meter.md) - [Trellis 3D Printed Enclosure](https://learn.adafruit.com/trellis-3d-printed-enclosure.md) - [TTL Serial Camera](https://learn.adafruit.com/ttl-serial-camera.md) - [Adafruit VS1053 MP3/AAC/Ogg/MIDI/WAV Codec Breakout Tutorial](https://learn.adafruit.com/adafruit-vs1053-mp3-aac-ogg-midi-wav-play-and-record-codec-tutorial.md) - [Adafruit 1.27" and 1.5" Color OLED Breakout Board](https://learn.adafruit.com/adafruit-1-5-color-oled-breakout-board.md) - [IR Sensor](https://learn.adafruit.com/ir-sensor.md) - [OLED TRON Clock](https://learn.adafruit.com/oled-tron-clock.md) - [Wave Shield Talking Clock](https://learn.adafruit.com/wave-shield-talking-clock.md) - [LSM303 Accelerometer + Compass Breakout](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout.md) - [Wireless Game Show Poppers for the Classroom!](https://learn.adafruit.com/wireless-game-show-poppers.md)