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RGB LED FOR MAKERS

Artium Nihamkin�a@nihamkin.com

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What are RGB LEDs?

  • Cheap RGB LED
  • SMD component price around 10 cents
  • Usually sold as part of a strip, matrix ring etc.
  • Can chain hundreds of LEDs together
  • Each LED is individually addressable
  • Use only 1 or 2 microcontroller lines total
  • In some cases the driver is embedded inside the LED package
  • Adafruit sells RGB LED based products under the names NeoPixel and DotStar

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SMD LED �Package Sizes

  • Marked by a 4 digit number
  • For example 5050 is a 5x5 mm
  • 5050 is the most common size

Image from:�https://www.flexfireleds.com/comparison-between-3528-leds-and-5050-leds/

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Physical�Configurations

Individual SMD

Breadboard friendly parts

Strips

Rings (as large as 60 pixels)

Matrices and flexible pads

Images from:�http://rgb-123.com/ws2812-color-output/

https://learn.adafruit.com/assets/21922

DHGate, Amazon

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  • As advertised - sub 10c for SMD part
  • 10c if you buy 100
  • 8.5c if you buy 1000

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  • Right page is from Adafruit
  • Notice the diameter difference

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Other Parameters

Strip background color

Waterproof sleeve or coating

Strip density (up to 144 LEDs/Meter)

Clear vs diffused

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Images from:�http://pololu.com

Amazon

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  • Strip density does not affect price much
  • Number of LEDs is the big factor

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Models Overview

https://github.com/FastLED/FastLED/wiki/Chipset-reference

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WS2801

Data and Clock

IC is not integrated with the LED

Old and slow

Image from: Random seller on DHGate

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WS2811 / WS2812

WS2811 is the driver

WS2812 is the integrated LED

WS2812B is the better variant

Only one data line required

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  • Waterproof sleeve adds ~10%

FAKE?

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WS2813

Similar as WS2812

Has a backup input

Protects against single LED failure

WS2818 is the stand alone driver

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APA102

Data and Clock (SPI interface)

IC is integrated inside the LED

Faster data rate

Faster PWM

SK9822 is a clone that has 5 bit brightness control but slower PWM

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  • eBay is cheaper than specialised websites
  • SK9822 is usually cheaper
  • Pricey relative to WS2812B
  • Beware of fakes - I payed $19.37 for that APA102 listing and got a fake SK9822.
  • Later discovered how to distinguish

FAKE

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How To Wire + Demo?

Almost all LEDs require 5V

Large (100+) chains require auxiliary power source

Easy to use libraries for Arduino/ish platforms

Demo?

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Thanks!

I was Artium Nihamkin

a@nihamkin.com

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https://github.com/alkhimey

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