(I'm not sure if this is the correct forum for these questions, but it seemed closer than any of the other choices.)
Two pretty basic questions:
I understand that digital pins 0 and 1 (on the Uno) are used for serial communication. Does this mean that those pins simply cannot be used for other I/O purposes? If the sketch does not open the serial monitor, can I use those pins for other purposes, or will it still cause a conflict when I upload the sketch itself through the USB cable? If the pins can be used for other purposes, do I have to use any special code to do so, or do I just refer to them like any other pin?
I have read in numerous places that the analog pins can be used for digital input or output, but I haven't found anything that tells me how to do so. Is any special code necessary to configure the pins for digital I/O or can I just do a digitalRead or digitalWrite which refers to (for example) pin A1?