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Author Topic: pin 2 pullup res  (Read 555 times)
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Cape Town South Africa
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On a freestanding board I saw it is recommended to put a 10 k pullup resistor from pin2 to Vcc to avoid noise.

Can I just set it to an input and take it high to enable the internal pullup?  
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As allways it depends on the context, Why was it recommend on the freestanding board? What was the question/application there? What type of noise?

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If the chip has a fairly recent arduino bootloader installed I believe it already sets the internal pull-up on to prevent the bootloader from responding to noise on pin 2 and hanging the chip up waiting for an upload that is not coming. If the chip does not use a bootloader then there is not concern about noise on pin 2.

Lefty

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Cape Town South Africa
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Thanks, it did seem odd when there are pull ups in the chip... I have seen it mentioned several times.
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