I have a breadboard running a 2560 Mega Arduino. I would like to exchange it for an Arduino Nano. If this is possible, can someone share the equivalent "ports" so the functionality is preserved.
Ken
The ports are defined in the schematic and the code. Without that I cannot give you a valid answer. There registers are different so if the code changes them it will be more difficult. Also it has a lot more I/O, hopefully note more then the Nano can support. Post your code using code tags and your annotated schematic. Frizzing will not be much help for me.
Arduino GPIO pin numbers are portable to any other Arduino, no change required.
Alternate pin functions may require updated pin numbers.
It is going to depend a lot on what you are using the Mega for, and which particular Nano you are intending to use (Nano has become a generic term for the board form factor, not a particular board/processor).
Show the code that you are running on the Mega then you can get some (even) more targeted advice.
Just about everything that can be at this point seems to have already been said. The fact that you made the request might already suggest that you have considered that a) the pin count of the Nano is much lower, b) the flash and dynamic memory (RAM) on the Nano is much smaller, c) you only have one serial port on the Nano vs the 4 on the Mega. If none of these considerations pose a problem, then it may be possible to use a Nano but we would still need to understand (as other have already said) the pins and GPIO functions used, (i.e. a more detailed description, preferably a diagram, and code, how many PWM or analog pins used in your project etc) to make an informed determination. For example if digital pins above 13 have been used (and your comment possibly indicates that they might have been) then they may indeed need to be re-mapped to alternative pins on the Nano and would need to be accessed via different port registers (which again your comment suggests that your code may be doing) because ports above D (the 328PB also has PORTE I believe) will not exist on the Nano. From the information so far, we have no way of knowing which pins or register ports ports are currently being used.
If you need more pins/functions than the Nano can handle and form factor is not too much of an issue then you could consider one of these (2560 Pro Mini) which is somewhat bigger than an average Nano, but has all of the same pins exposed. On the other hand , there may be no point doing that if the Nano (R3, R4 or even Micro[5V version]) will suffice, so the further details requested above will be very helpful to make that determination.
