My front door needs a new paint job (well, actually a bit more than that ;-)), but that got me wondering if I could build some kind of sensor behind the mailbox to detect when it is (slightly) opened.
The idea is to put in a custom build PCB with an ATMega, powered by a CR2032, just like I did for the moisture sensor project I did.
But to give you an idea of the situation, here's a picture (as seen from the inside) of the mailbox/hole:
As you can see, there is some space at the top, in which I could easily snug a PCB with a CR2030 to power it. AA batteries are a bit too much though, so that's no option. AAA might work as well, but I prefer it to be small.
I am thinking of using a micro switch, though I'm a bit worried that it might wear out too soon. Also, I would like to keep detecting when it's open, so I know when it closes again. Given the situation, the micro switch probably won't be "pressed" all the time when the mailbox opens, so I still have to give that some thought.
Still a long way to go, but it would be a nice addition to my home automation system.
...to be continued...