I am the proud new owner of an Arduino Due and am looking at my power supply options. It states in the "getting started" page that the Due can be powered from a USB port (which of course is at 5V), however it also states if using an external power supply, the Duo must be powered at 7-12V.
It also states the the board will be unstable if powered at less than 7V. Should I get myself a nice 9V power supply or can I just power it through the USB permanently?
A standard USB port provides up to 500mA of current. As long as the total current does not exceed that you can power it through USB permanently.
Is that because a USB port can't supply more current than that, or because it will damage the Arduino by supplying more current than that?
I have a USB charger rated at 2A that I was hoping to use...
Calloutman:
Is that because a USB port can't supply more current than that...
The USB standard calls for 500 mA. A standard USB port can provide up to 500 mA.
...or because it will damage the Arduino by supplying more current than that?
If the circuit tries to draw more than what a power supply can provide the most likely outcome is that the power supply will shutdown. In the case of USB ports that is required by the standard.
I have a USB charger rated at 2A that I was hoping to use...
Feel free. The circuit uses what it uses. The power supply supplies what the circuit needs and no more up to the maximum (2A in your case).
Due or Duemilanove? They are very different boards.
Calloutman:
if using an external power supply, the Duo must be powered at 7-12V.
This is because when used with an External Power Supply, the regulator circuit used requires at least 7volts.
When powered via USB port, there is a different regulator circuit used that works with USB's 5volts. (Note that this is only on the Due. The Uno/Duemilanove/
I have a Due.
Thanks everyone for your very helpful replies, that has cleared up my problem!! 