I'm pretty much a complete hardware noob. I spent yesterday getting a Nano c6 board to activate a relay after 2 seconds of powering on (and when the button is depressed.)

The code works fine while attached to the computer on which I'm running the arduino ide.

But when I plug it in to simple usb power, it's dead as a doornail. If I plug it back into the computer, everything's fine.

I know I'm missing something silly. But...what?

I can paste the code if you'd like. But I'm not sure what difference it would make.

The thing I'm trying to get done is "Turn on this relay for 1 second when the nano gets power." So it's nothing too complicated.

What am I missing?

Thanks.

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