Using interrupts with an LDR (pro min)

[shabba]

Hi all,

I want to use an analog LDR to detect when my mailbox is opened and I want to run it on batteries. Hence I would like to wake only on sensor detection. The pro mini only has digital interrupt pins (not sure how analog would work anyways - thresholds?) - Anyone know any way of setting this up? I know I could use reed switches etc but I'm curious about this now!

Thanks!

[maltimus]

@shabba Why not use the LDR on a digital interrupt ? LDR should be able to swing the voltage enough to trigger a state change.

[shabba]

@maltimus Because on a dark day I was concerned this would not be enough to trigger. I intend to test it though!