I am trying to find out if it is possible to light up multiple LEDs with a standard Arduino Uno. Say I have 500 LEDs and logically I give each one of them a number from 1 to 500. In my test scenario I'd like to say something like "LED No 275 On" and as a result only have this single LED turning on while all others remain off.

Is there a way to do that at all? Or will I have to use many different Arduino Unos for that?

  • With these kinds of amount, people generally use multiplexing. You could light 500 leds with "only" 45 pins. You can do this yourself, or use a dedicated IC like e.g. the MAX7219.
    – Gerben
    Dec 15, 2015 at 16:24

2 Answers 2


Rectangular matrices and strips of dozens or hundreds of LEDs are available from places like Adafruit and Sparkfun, with added circuitry to allow you to address and manipulate single LEDs easily. Some are single color, some are RGB. Adafruit in particular has many products like this and many tutorials on how to use them.


Probably the simple answer is to use 63 8-bit shift registers, with a LED and resistor attached to each shift register output pin. There are many good examples of using shift registers to add output ports on the internet.

The shift register solution will let you turn on just one LED at a time, or if your power supply can stand it, all 500 at once.

This question shows how to go about the expansion Is there a way to have more than 14 Output pins on arduino? It also gives some other valid options.

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