Making: Building a Smart Mailbox

Building a Smart Mailbox – The Problem

So…I have a mailbox outside my house which is mounted on the gatepost which receives mail from the postman.  My problem is that I never know when mail is actually waiting, sometimes the postman is early, sometimes he is late, as it, of course, depends on how much mail he has to deliver within my area etc.

I need to know when mail is waiting so I can go and collect it, otherwise, it is a wasted journey from my front door to the mailbox each time!

Now it’s not that I’m lazy or I live like 2 miles from my gatepost (like a friend of mine in Canada!), it’s that tech should be there to make life easier and more interesting, as long as I let it.

So I let Tech be my postal saviour and decided to come up with a build for a solution, one that I can improve over time and one that will only get better as it works around me and I have written this blog post so you can smart-enable your mailbox too, if you are as sad as me! 🙂

Building a Smart Mailbox -The Design

(PS – This is the Pi Version, see my much improved LoraWAN low-powered version which I will add soon)

I decided on my usual KISS (keep it simple stupid) strategy. I researched various mailboxes and found a good study one by Brabantia, one, more importantly, that has room to retrofit some sort of switch or sensor so I could detect mail coming into the box in a reliable way, then I decided on the following: 

  • I would use a Raspberry Pi 2 and use the GPIO pins to give me a normally open switch circuit that I could read in code and perform various actions (via an add on hat)
  • I would retrofit a Momentary High Push Plunger Micro Switch to the mailbox flap, then take Cat 5 cabling to the mailbox that would carry the switched pair, this would be then soldered onto the switch contacts.
  • The Pi would be mounted in an existing enclosure that is used for another purpose, giving it watertight and weatherproof protection
  • When the flap is opened, it would send me an email and or text message (using the Telecoms Cloud Communications Platform API) to let me know that mail was waiting

I’m going to add pictures of my mailbox soon, as I’m just trialing the Green Eco mailbox below first as you will see below, it has a pretty cool feature to water a plant and I’m looking to improve my current design with this very soon.

Building a Smart Mailbox -Parts Listing

(I’m going to add code samples and a setup guide soon to this post to help you build this)

Future Improvements that I’m Planning:

  • I want to add a camera to take a picture of the mail once it goes in, or of it waiting – I want to know it not junk mail or something I don’t want, so it could attach a photo of it
  • I want to put an optional feature in that knows the local postal service (Royal Mail etc) delivery times and uses this window to add a priority on the email, as mail received outside of these hours is likely to have a higher chance of being junk or “local” mail, and therefore possibly less of a priority
  • I’m’ going to add a battery and solar panel so I can make the solution work without mains power – I don’t actually need this, but some of my readers on here have asked me to add this option
  • I’m going to use a lower powered solution by moving to using a ESP8266 As a Microcontroller connected to the Liverpool LoRaWAN network I helped setup, it uses lower power while moving the entire solution off WIFI and onto a dedicated Internet of Things (low power low data) network which gives me many other benefits

If you go ahead and build this or something similar, please let me know or feel free to ask any questions on the comments below.