Hi,
I was just wondering if the RESET* pin on the Duemilanove can be used to reset other devices instead of triggering a reset on the Arduino itself?
i.e.
If you wired the Arduino RESET* -> IC RESET* then would that pin show HIGH while the Arduino was running, and would it drop low when the xDuino is reset by the firmware (e.g. when you upload a new sketch etc.)?
[edit]
Crossed out a very misleading line there. Not what I intended.
[/edit]
No, that won't work. Use any of the DA pins for that.
Korman
would that pin show HIGH while the Arduino was running, and would it drop low when the xDuino is reset by the firmware (e.g. when you upload a new sketch etc.)?
Correct, the rest signal can be used to reset other circuitry and other circuitry can be used to rest the AVR as long as it uses open collector/drain drivers.
I may have misread,
instead of triggering a reset on the Arduino itself?
No, not "instead of", "as well as". IE everyting connected to reset will be reset.
would that pin show HIGH while the Arduino was running, and would it drop low when the xDuino is reset by the firmware (e.g. when you upload a new sketch etc.)?
Correct, the rest signal can be used to reset other circuitry and other circuitry can be used to rest the AVR as long as it uses open collector/drain drivers.
Graynomad, are you sure about this? The datasheet seems to indicate, that the PC6/Reset-pin is input only when used as reset. Only when it's disabled with the RSTDISBLE Fuse it becomes a general purpose I/O pin. Also all the timing diagrams about resets don't indicate anything of the sort.
Or did you just mean, one can attach the reset pins of other circuits in parallel so that all get reset at the same time when the reset button is pressed?
Korman
You're right, what I rather badly tried to describe was that the signal can reset other logic, say for example when the sketch downloads all logic connected to RESET will be reset.
But RESET cannot be driven from the AVR unless as you say you disable the reset function.
Sorry for the confusion.
I think you get what I'm after - athough part of that I did phrase badly.
I'm not trying to stop the Arduino resetting, it will still reset. But essentially, I was hoping to use the RESET line to automatically reset an off-board IC when the Arduino resets. Nothing in the sketch or off-board needs to have any say in the matter.
Yes, a standard digital output (held high while the sketch is running so that reset creates the falling-edge) works - I'm doing that at the minute, but would rather not waste the pin.
I just re-read my OP... I did phrase that very badly indeed.
"instead of triggering a reset on the Arduino itself?" is not at all what I actually wanted. 
Call it a brain fart.
So, confusion all around then. 
I was hoping to use the RESET line to automatically reset an off-board IC when the Arduino resets.
That'll work.
Hahaha. I didn't really give you a fair shot at this one, did I?!
But we got there in the end.
Thank you very much, both of you, for the help - it's a useful little trick that'll add a tiny bit more elegance to a few of my projects.