I've searched around for a tutorial or discussion on this and have not found exactly what I'm looking for. I have learned a lot about the sleep capabilities of the Atmega 328p and the code for sleeping and waking in my searches, but have yet to answer this question for myself. Hopefully my question is not terribly redundant, sorry if it is.
This is a somewhat simple task and question so it seems, I want to use the on board RESET button found on the Pro Mini 3.3V Arduino as a power or sleep mode button.
If the board is on and running sketch, I want a 3 second hold of RESET button to enter SLEEP_MODE_PWR_DOWN
If the board is in sleep mode, I want a single button press on the RESET button to wake the board. If this has to cause an actual reset to the board that is acceptable as well.
Is this possible? Or am I restricted to pin interrupts on INT0 and INT1?
While the button is pressed, that grounds the RST pin until you let go of it.
No code can run while RST is held low.
Ergo, you cannot repurpose the reset button in software.
You must wire up an additional button, or cut the trace between the reset button and RST pin, and replace it with a wire to a different pin, to modify the board to turn the reset button into a something-else button. But, then you won't have a reset button.
Okay thanks, that makes sense. I guess I could modify the switch connection, and then place a new reset button elsewhere connected to the reset pin. Seems silly when I could just put a power switch elsewher instead. But the thing is that the placement of the reset switch on the arduino mini is perfect for my design as an on/off button. So it would be nice to use a switch in this location as such.