I am making a project that uses an Arduino nano and a sound detector module to power a 1m LED strip. I got the idea from this video and I am not sure how to power it. My LED strip flashes for a split second and turns off, and people say that the usb power source I am using is not enough power. I am worried though that if I use a more powerful power source that it will fry my Arduino. I am very new to this and I have no idea what to do.

  • How many LEDs on your strip? Is it an RGB, RGBW, or WS2812 strip? – Majenko Apr 25 '19 at 10:57
  • it is WS2812 with 60 LEDs – Ethan Garrett Apr 25 '19 at 11:01
  • When using a power source, which can provide more current with the same voltage, you cannot fry your Arduino with the change. The components will draw the current they need, not more. The rest is reserve and not a problem. You can only fry components, if you draw more current through them, as they are capable of. For example: You can fry your PCs USB port, if you draw too much power for lighting the LEDs. If you give power to too many LEDs through the Arduino (for example by using Vin for power and connecting the strip to 5V), the strip will draw too much power for the regulator and fry it. – chrisl Apr 25 '19 at 11:02
  • Ok, so minimum current capacity you need is 60 * 0.02mA * 3, which is 3.6A. Plus some more to power the Arduino. You want a 4A power supply or better really. – Majenko Apr 25 '19 at 11:02
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    No. Use a 5V 4A power supply. Connect it to both the LED strip and the 5V of the Arduino. – Majenko Apr 25 '19 at 11:20

WS2812 can draw 60mA when on full white, x 60 LEDs = 3.6A. If you have a 4 to 5A external 5V supply powering all the components, you'd be okay. If you're trying to power the strip from the Nano 5V line thru its regulator, the regulator will overheat and shutdown.

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You could use a relay and have a larger power supply that will light up the LED strip on the other side, after the relay gets the signal to turn on.

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  • Is there any way I could do this without external hardware though? Apart from the sound detector, Arduino, led strip, some wires, and a usb cable, I would prefer not to buy anything else, as I need this for a school project and it would take too long to ship. – Ethan Garrett Apr 25 '19 at 11:09
  • @Ethangarret You could do it with just the battery and a transistor if you have those, otherwise probably not the arduino nano just can't supply the energy that is needed. – BeastCoder2 Apr 25 '19 at 11:12
  • ok, thanks. Would it work if I power the led and Arduino separately? – Ethan Garrett Apr 25 '19 at 11:15
  • Yes, and then you could use a switch to turn it on and off. – BeastCoder2 Apr 25 '19 at 11:23
  • That is, if they are connected by that switch. – BeastCoder2 Apr 25 '19 at 11:23

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