Introduction
Programmable LEDs come in many different module forms - strings, matrices like Adafruit’s NeoPixels or the RGB123, or even 5mm LEDs. Note that while physically different (some are built into LEDs, some are separate chips), the WS2811/WS2812/WS2812B/APA104/APA106/SK6812 all work the same way electrically. The Youtube LED Strips, what’s the difference explains some of the differences between these. It is a good starting point when selecting what kind to chose for your project. If you prefer reading, try the page LED strip lights - everything you need to know before you buy.
I am primarily interested in using programmable LEDs as a light source for a handheld spectrometer, and that only requires a single LED. The versions I have tested include 5 mm encapsulated LEDs, a breakout board, and a strip that I cut into single units.
KY-009 3-color full-color LED SMD
The simplest modules only contain a single SMD 5050 RGB component with connection points for red (R), green (G) and blue (B), plus ground (- or GND). For this kind of module you have to connect three separate and individually controlled power wires, including resistors for each.
The KY-009 3-color full-color LED SMD module component represent the simplest kind of module, where you have to wire using separate and individual power, with resistors on each power.
8 mm LEDs
The ws281X series of addressable LEDs with inbuilt control chips are available as 8 mm LEDs. They look similar to older LEDs, but work differently. In Sweden you can get these kind of LEDs from pchbutik at about 0.50 USD each.
Breakout board
The breakout board is more expensive (at least in Sweden, where pchbutik sells them at about 3 USD each).
LED strip
LED strips are produced by a range of vendors and offered in many different versions. Usually the strips have either 30 or 60 LEDs per 100 cm. The number of LEDs naturally affect the power requirements and different strips have different solutions. Selecting a strip this requires careful consideration in order to get what you want. For use with Arduino you want strips that operate on 5 V. Some strips are encased and waterproof, other are not. In Sweden Elfa offers a wide range of LED strips.
