Handling floating pins

New user...and I mean REALLY new. Never worked in C/C++ and never worked with the Arduino chips. Goal or general interest is robotics.

Since all the pins are floating unless otherwise addressed is it standard operating procedure to pull each on LOW or HIGH with a resistor or pull them HIGH with internal resistors or just ignore them? In other words are you overtly addressing unused pins?



I would only pull them up/down if you find they are interfering with neighboring pins (which can occasionally happen). I would suggest the internal resistors in that case :).

I would only both pulling them up/down

Once more, in English, please. ;)

TchnclFl Thanks!

PaulS Not sure what you mean???


Once more, in English, please.

Woah my bad :P. I was talking to someone while I was typing that ;D. I’ll go fix it :P.

Boy, I'm really screwed up, I understood exactly what you were saying. :-*



Generally for reliability all unused inputs should be pulled high or low through a resistor.

In practice, for a development system like this, that is not exposed to severe conditions simply leave them alone.

If this worries you then simply define the unused pins as outputs and then they will no longer float.

can i also pull down digital pins 0 and 1? I think they are causing the interrupt firing on pin2.


No that will stop the serial port from working and you won’t be able to up load anything or get printing out on the monitor.

I think they are causing the interrupt firing on pin2.

No they are not.