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I was trying to follow this project and I fried my Pi, (it started smoking and shut off).

I'm hoping you guys can help me identify why it fried so i don't keep trying things and cooking Pi's.

In this image I have spliced a 5V 10A power supply and soldered it to 2 of the wires on the neopixel strip. Note that brown is hot and blue is ground.

enter image description here

You can see in this image that my brown wire is connected to the power on my breadboard and the blue is connected to the ground on my breadboard.

enter image description here

You can see in this image that there are 4 wires coming out of the neopixel strip - 2 black, 1 red, and 1 white. One of the blacks and the red are what I soldered to the power supply. The other black and the white I haven't done anything with yet.

enter image description here

Is there anything obvious that I did wrong here? Some possibilities that I'm thinking could have caused me to fry my raspberry pi:

  1. I accidentally connected the 5V from the power supply to the 3V3 pin on my raspberry pi instead of the 5V

  2. I have the wrong side of the neopixel strip?

Any other ideas?

Darth Vader
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Catfish
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1 Answers1

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The LED strip has two ground cables. It's hinting at building two circuits, as spotted in the comments; a power circuit and a data circuit. These should be kept separate.

Connect the power supply to Red and Black of the LED strip, as you have done. Do make sure to use a DC power supply though. Remove your Raspberry Pi connections from this power circuit.

For the data connection, use the White and Black of the LED strip. The white cable may accept 5V or 3.3V data input and will draw a minimal amount of current from the Pi itself. By sharing ground between power and data circuits you are making them "safe" to interact - as long as they are both DC circuits.

The result

neopixel strip to raspberry pi

Sorry for the crude drawing!

I would power the Raspberry Pi from a separate USB power supply (not from an expensive laptop during testing, though!) Were the LED strip, cat, hampster or Roomba misbehave and short the 10A supply then the Pi would keep running. With other types of load you could also experience line noise, interference or dangerous spikes. Rule of thumb; keep them apart.

Also some possible reasons for the Rasplosion;

  • Using an AC power supply (a possibility based on your colours)
  • Connecting a 5v supply to the 3.3v GPIO pin (from the comments :) )
  • Connecting two power supplies (something I would do)
  • Drawing 10A from GPIO (not likely from your photos)
NoChecksum
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