Arduino Forum

Using Arduino => Installation & Troubleshooting => Topic started by: stevenette on Apr 29, 2019, 06:03 pm

Title: Uno only works when plugged into USB port
Post by: stevenette on Apr 29, 2019, 06:03 pm
Hello,

I am deploying a bunch of arduino Unos throughout my place, all with the same program and same setup. They are all powered by a 12V battery, and they all work fine, except for one. I have the debug LED blink every loop, and this one just flashes waaaay faster than the rest. My switches and other components I have hooked up to it don't work. That is until I plug in the USB to the laptop. As soon as I do this, the blinking speed is normal, all my components work etc. As soon as I unplug it, everything goes back to malfunctioning. The battery is full, no shorts or loose wires, I can't think of anything else.

If I am missing something I would appreciate any help. Thank you!

EDIT: I forgot to mention a lot of the previous posts have mentioned a voltage regulator, but I have Xbees hooked up to all of them, and I can talk to it just fine, so it is powered fine.
Title: Re: Uno only works when plugged into USB port
Post by: stevenette on Apr 30, 2019, 01:22 am
I am able to use the power off of the 5V output fine without the usb plugged in, but none of the logic is working. Once I plug the USB into the laptop, however, I now have logic control back.
Title: Re: Uno only works when plugged into USB port
Post by: dmjlambert on May 02, 2019, 04:19 am
It is possible your Arduino is resetting often because of low power to the MCU or problem with whatever regulator you are using (onboard or off board).   Please post a schematic of your device.