I'm planing using the Atmega2560 in my future projects and replacing the atmega328 that I use, my question is while I was using the atmega328 I always used only one 5V 800mA regulator to power up
the controller and use almost all pins but what about the atmega2560?
Will the atmega2560 work with a 5v 800mA regulator, the question is yes will but what about the 100pins, I'm planing to use almost the half controller digital and analog pins, will the 800mA be enough or should I get a regulator with more mA support?
800mA is plenty for the '2560 itself, per the datasheet. Using the pins, in and of themselves, doesn't use a significant amount of current - but if you're driving into a load, that's different. Absent more details on what you're driving and whether they're powered from that same 5v rail or something else, I can't comment further.
Planing to use it just to give some digital signals like 0 and 1 to power up something but I use the Digital
pins only as switches not to power and the analog pins to read some data from IR sensors, as well a nRF24 but that will be powered by a different regulator 3.3v
I'm just new to 2560 and better to ask then build.