I'm working on a project using an ATtiny13. I have one momentary push button that is attached to PB0 and utilizes the internal pull-up resistor.
I would like to use this button to wake the device up from sleep mode. I am pretty sure I can do this by leaving the internal pull-up active and using the pin change interrupt to wake from shutdown-mode. Am I wasting a lot of power by leaving this pull-up enabled? Is this the best way to do it in my case?
I also noticed that PB0 has the alternate function of PCINT0. I read that an external PCINT0 can be used to wake up the device but I don't really understand how. Is there another option here? Since the button connects to ground I don't see how I could use it as an external interrupt but as I said I don't relaly understand how this option would work.
Thanks for your insight and guidance!
It seems I'm confusing PCINT0 with INT0. Upon further investigation I see that INT0 can wake up the device from power-down mode and can be done from a low level. Does this mean I still need the internal pull-up enabled and once again, how does having this enabled effect the power savings?