I'm working on the sound reactive led lamp as my first project and have slightly different materials to start with. First I'd like to simply learn to power the LED strip.

from https://www.youtube.com/watch?v=5oRir4dck_w

I'm attaching pictures so it's as simple as possible, but I'd like to confirm where to attach the wires on the uno and the basic logic behind how to get from the attempt I have now, to actually turning on the LEDs. Thanks so much!

(I think the images show up but please let me know if not)

enter image description here

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1 Answer 1


A good question, best asked as you did before frying something. My Arduino rule #1 A power supply the Arduino is NOT! Connect the ground of the LED power supply to the ground of the arduino. Then connect the data line, as you have it in your picture. If you try to operate as it is in the picture the odds are high that you will fry the regulator on the Arduino depending on the output of the wall wart. You have a 5V power supply connected to the Vin connector, that does not work as it goes through the regulator and protection circuitry before getting to the processor. You need to power via the 5V pin with a 5V power supply. This can also be used to power your LEDs assuming they do not pull much over 1 amp. If you want to power by the connector, my preference, you need about 7.5 to 12 VDC. The additional filtering does not hurt and can only help. It also helps to protect from transients.

  • Thanks for taking the time to help me. So the vin is what it has built in and I need a different power supply module connected to the 5v pin?
    – Ellie S
    Commented May 18, 2022 at 22:04
  • Your 5V DC power supply should work on the +5V and power the arduino just fine. Be careful and do not connect backwards even for nanoseconds as there is no protection for that as there is on the Vin. An external DC power supply between 7.5V 12VDC will work. As you approach 12V and beyond on Vin the on board regulator will start getting hot, such things as Motors will overheat it. The protection circuit will allow you to power it externally while connected to the USB and your computer.
    – Gil
    Commented May 19, 2022 at 14:57

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