Powering WS2812B through USB

Hey Noob here,

for a shool project i want to build a keyboard using an Arduino Micro, as an extra i wanted to add a few WS2812B leds.
My question is if and how many LEDs i could power through the micro usb Port when it is connected to the PC?

The real answer is none because the Arduino is not designed to be used as a power supply if that is what you have in mind

How many LEDs do you mean when you say "a few" ?

1 Like

Yes, you can do that. However you have to somehow absolutely limit the current. You have to either use few LEDs, or run more of them at extremely low power settings.

I have run as many as 256 NeoPixels directly from an Uno 5V pin, but each LED was only set to 1/256 intensity, and only one colour.

I ran a strip of 60 like that for a while, maximum 32/256 intensity.

If you expect to run them at full intensity, you can only use a few, for example 2-8

1 Like

I believe USB2 is rated for 1 Amp. Each RGB LED can require up to 60mA. So that's about 16 LEDs. Of course you need to subtract a little for the Arduino itself, and anything else you are powering.

And you really shouldn't run 1A through the Arduino but 5V from the USB can be shared.

USB1 is 100mA or 500mA. USB 2 is standard the same. After coming the battery charging specification higher rates are possible.

Going out from 1A is very optimistic. How much are the components rated on the Micro?

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.