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Topic: external 5V at +5V pin, and USB connection (Read 1 time) previous topic - next topic

Yvan

:~ :~
As I wrote in another thread with the same question, I decided not to take chances. I will bend the pin going into +5V, so grounds will be connected, shield will be powered externally, and Uno will get +5V from USB.   8) :)
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     /__/  /    \      ** Registrovani korisnik Linuksa #291606 **
    /  / \/  /\  \     ** Registered Linux user #291606

sixeyes

When I powered my Mega from a PC power supply and then plugged in a USB cable everything was fine but if I turned on the power supply after it was powered by the USB, the PC power supply fan would stall and measured over 0.3A flowing into the power supply. As far as I could tell this was caused because the two power supplies (PC & USB) differed by less than 50mV.

Yvan

But noting was fried... There was no smoke coming out of it. :) 8)
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     /__/  /    \      ** Registrovani korisnik Linuksa #291606 **
    /  / \/  /\  \     ** Registered Linux user #291606

sixeyes

No the Arduino was fine. In the end I modified the USB lead so that it didn't provide power, just data.

Yvan

I finally ended powering Uno with both USB and shield +5V, and nothing is fried, I can confirm that it can be done with no damage to the board.
___   ____
     /__/  /    \      ** Registrovani korisnik Linuksa #291606 **
    /  / \/  /\  \     ** Registered Linux user #291606

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