I wish to power my arduino from an external regulated power supply hooked up to the 5V and gnd pins. Is there anything I should watch out for?
Is there a limit of the amount of current I should supply to the pins?
I'm looking at a 5v 2.5A supply at the moment.
Afaik, current isn't imposed by the supply, it's drawn by the consumer.
Add a diode from 5V (anode) to Vin (cathode) to avoid reverse driving the regulator.
The board will only draw the current it needs, 30-40mA or so with no IO loads.
Just be sure its a regulated 5V supply, if it outputs more than 5.5V you'll trash the
board.