Mail box monitoring ... in an apartment building

My mail comes at a seemingly random time between 11:00am and 8:00pm

live in a building where the mail boxes are downstairs. (I live on the 5+ floor so I don’t think there is a signal that will reach.

I have detected a semi-public wifi network in the area. It uses mac addresses of your devices to automatically log you in. So, I could register the mac address of the spark core and possibly get it online. I’m excited to try this because this network is all over the place.

The real challenge is getting power there. The mailbox is tiny. There are no outlets. I’m stuck with battery. I’ve been reading about ways to make that more efficient.

I know the mail will come within a 9-hour window… once the mail comes there is no reason to keep monitoring the box for change. Can I use that info to save power?

I could use the folowing to trigger the notification:

  1. light sensor as the box is dark
  2. magnetic door/window sensor
  3. motion sensor.
  4. other ideas?

What sensor would be the best for energy?

Oh I don’t need to get the update instantly. And the postperson takes a long time to fill the boxes so I think I could get away with checking in every 10min.

If I can get the wifi to work I might try the cellular spark… but I bet it’s a power glutton.

@futurebird, the solution is actually much simpler! The Core can be put in a sleep mode where power consumption is very low but it can be awakened with an external event. That event could be a simple as a switch that activates when the mailbox door is open. Or you could use a magnet/reed switch combo. A switch instead of an electronic sensor will require the least (if any) current.

The bigger issue in my mind is the wifi signal. In the metal enclosure of your mailbox, the wifi signal may not be able to get through. Have you given this some thought? :smiley:


I am also interested in this project, for my regular mailbox. Eventually I want to switch over to the Electron to do this. Have you gotten to progress with this project?