So, essentially no current will flow into an output pin when it is turned off (low)? But when it is turned on (high) there is maybe a 30 or 40 ohm resistance?
Is there any resistance on the input pins? The Arduino docs suggest that there is, but the Atmega datasheets makes me think there is no resistance when configured as input.
Input pins make extremely small demands on the circuit that they are sampling, equivalent to a series resistor of 100 megohm in front of the pin.
If the Arduino docs is right then where would that 100 megaohm resistor be in terms of the pull-up resistor?
I think that going back and forth between the atmega docs and the arduino docs is confusing me..