How many Neopixels can the Feather handle using only the onboard USB C

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fuzzybat23
 
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How many Neopixels can the Feather handle using only the onboard USB C

Post by fuzzybat23 »

Seems not many here have asked the right question. They only stop at asking How many? Ok, well that's where you get all theoretical and stuff. A more direct answer needs a more direct question. Given how much power neopixels draw, what is the ceiling on how many neopixels can the Feather RP2040 SCORPIO 8 channels handle using only the onboard USB C that connects to and powers the Feather?

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dastels
 
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Re: How many Neopixels can the Feather handle using only the onboard USB C

Post by dastels »

It depends on the USB port that you're plugged into. USB 1 & 2 top out at 500mA, USB 3 can go to 900mA, USC C can go higher and is much more complex.

How many NeoPixels you can handle depends on how they are used (color, brightness, and how many pixels are lit). An RGB NeoPixel requires 60mA when it is showing full brightness white (R, G, and B all set to 255).

So it really depends on what you are plugged into (the USB C connector on the Feather is irrelevant) and how you are using the NeoPixels.

Given you are talking about using a SCORPIO I assume you are planning on using quite a few NeoPixels. In that case, I advise external power supplies. See https://learn.adafruit.com/adafruit-neo ... -neopixels.

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adafruit_support_bill
 
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Re: How many Neopixels can the Feather handle using only the onboard USB C

Post by adafruit_support_bill »

Note also the pinout of the Scorpio includes only signal and ground connections for the Neopixels. In all the product photos with active pixels, you can see that power is being supplied externally.

If you are going to be driving more than a few dozen pixels, you should not try to power them through your Feather, or it might end up being the 'fuse' in your circuit.

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