I'm developed an application on the Arduino which is working fine, i have mains power onto the board and the USB lead connected to the computer, when i pull the USB out then the program falls over! Am i right in thinking in the Arduino cant work without the USB??
Shouldn't be a problem.
You can power an Arduino fine via the DC jack or even wiring +5v & Gnd to a new (male) usb plug and plugging that into the normal socket on the board.
Thats good then.
Any idea why, at the moment, its not working via just the power yet does work via USB. (i'm no hardware expert at all, as you can tell) but surely mains provides more power than USB??
Are you using the right kind of adapter - e.g. correct polarity and voltages within the acceptable ranges?
(Apologies that I can't remember what the range is).
but surely mains provides more power than USB??
Well it depends on what sort of mains adaptor you have. What is the voltage output of the mains adaptor and where have you got it connected?