Mix Any Color: Red, Green And Blue LED Combined Provide A Universal Color LED

RGB LED contain at minimum three separate LED in the colors red, green, and blue. In addition, cold white and warm white LED can be added to provide more levels of brightness and contrast.

Please do not confuse RGB LED with programmable RGB LED. Simple RGB LED (as discussed here) are often used in cheap LED strips: they can change color, but they can change the color only for the entire strip.
Programmable RGB LED come with a built-in chip per LED. They are more expensive but can be individually controlled. Each programmable RGB LED can have its individual color and brightness.

Identifying Anode and Cathode

Classic RGB LED have four pins: a common ground, and three pins for the three individual LED.

  • Common Cathode (-): the longest pin is the common cathode (-).
  • Red: On one side of the common cathode, there is only one pin. That’s the anode for the red LED
  • Green and Blue: on the other side of the common cathode, there are two pins: first the anode for green, then for blue

Be careful:

  • Do not confuse LED type: programmable RGB LED also come with four pins, however they are completely different: two supply power, one is the digital input, and the other one serves as digital output to daisy-chain the signal to other programmable RGB LED in that string.
  • You are responsible: In classic RGB, you are solely responsible for providing the correct current to each individual color LED. Each color has a different forward voltage and needs a different series resistor. If you want to connect multiple RGB LED, it’s therefore much easier to use a constant current power supply. In programmable RGB LED, the built-in chip takes care of current control, and you just submit 5V, 12V or 24V to the LED (depending on type).


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(content created Mar 03, 2024 - last updated Mar 18, 2024)