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Self Powered USB, Cannot Connect Arduino Via Internal USB

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Re: Self Powered USB, Cannot Connect Arduino Via Internal US

By Belial88
-  Wed Jun 11, 2014 7:57 pm #171755
Would a powered usb hub not be a good choice, one that was powered by the battery that was being charged?

And I'm considering just using the adafruit trinket for the servo control, that might be the easiest way to do this...

Not sure how to do the trinket code thing :X

Re: Self Powered USB, Cannot Connect Arduino Via Internal US

By Valen
-  Thu Jun 12, 2014 2:04 am #171905
I don't know about a powered usb hub. It likely needs more than the 5 volt comming out of your USB battery.

The trinket works on 3.3 volt internally. So you need to make sure the servo you use can work with signals at that level. (Or insert a level shifter circuit) If you connect a battery and the USB plug to the pc at the same time then the battery will not be charged by it. There are Schottky diodes to both preventing current to flow into the other end. And there will be a small drop across the diodes.
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