I know there is a simple circuit you can make to be able to read an analog pin but what if I don't know if my device's pin is giving me analog or digital? If I try to read from that pin anyway am I going to damage anything?
** EDIT **
I'm not talking about reading some mystery "analog pin" on the rpi it's self, I'm talking about reading output from and entirely different source. If THAT pin is outputting analog data (which I'm not sure if it's analog or digital) is it okay for me to try to read from the pin either way just to see what happens or am I going to fry something? How can I decide if it's analog or digital anyway?