Connect Push-Button to Analog-Pins

Hi,

as my digital pins are nearly all in use, I asked myself if there is a possibility to connect a pushbutton like this one (http://www.conrad.co...product/706140/) [font="arial, helvetica, sans-serif;"]to the Analog pins?[/font]

Is this possible via the analog pins and if yes, is there some kind of tutorial how to do it with the analog pins?

Is there some restriction in the cable length between button and pin? Do I need additional resistors or something like that? (sorry I'm no electronics guy ;-))

Thanks in advance.

The analog pins also have digital I/O function, they work as InputPort, OutputPort etc. parameters just fine. They will switch into analog mode when you pass them to AnalogInput class. There is one difference though, the analog inputs are not 5V tolerant, so you'd want to use 3.3V input signal only. The buttons should work fine, there is generally no restriction of the cable length, as long as the resistance is low enough so the voltage is between logic level thresholds. I am not sure what is the mechanical construction of the button, you'd probably need to add a debouncing circuit (resistor and capacitor), or handle it in software - there is lot of examples available on the Internet, and it has been discussed on the forum too...

Ok, thanks, when they are also just Digital IO's then there is already some example on the Wiki here.

Many thanks!!!