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Author Topic: Connecting arduino uno 5v output directly to digital i/o?  (Read 916 times)
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Hey I'm just starting with the arduino uno and electronics in general, so I just have a simple question to ask.

Can I connect the arduino uno 5v output through a button directly to a digital i/o without ruining the board? - Or do I need to have a resistance in between? If so how much resistance is needed?

Thanks in advance

Regards
Jesper
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Hi Jesper,

Welcome in Arduino land.

Please take some time to go throught the tutorial section like - http://arduino.cc/en/Tutorial/Button - as there is a lot to learn. IN a few days you will learn a lot, and although the sketches may seem simple there is a lot of know how in them.
(you will find the answer to your question in the above link)

Another site with good tutorials is ladyada - http://www.ladyada.net/learn/arduino/ -

For more know how about electronics - http://openbookproject.net/electricCircuits/ -

Have fun, and if there are questions just let us know.

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Rob Tillaart

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Thx
Okay basically they do the same thing as I have done - except the placement of the pulldown - which I have placed at the same leg as the 5v is connected to and then to ground. But that shouldn't make a difference?
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But that shouldn't make a difference?
Yes that makes all the difference with out the pull down it will simply not work. The input will float:-
http://www.thebox.myzen.co.uk/Tutorial/Inputs.html
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Hmm okay - makes sense. So just to be sure, I should have a pulldown on both my outputs and inputs, and not only my inputs?
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Only inputs.
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Thanks for the help both of you smiley-grin
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