Smart letter and parcel box

Finally I also wanted to share some idea for the usage of Shelly and Home Assistant which is in my opinion an unbeatable combination.

Some time ago I bought a combined letter and parcel box (“Safepost 65 Briefkasten mit Paketfach”) which is independant from who delivers the parcel. It can be opened once by anybody and with opening a locking mechanism prevents the door being opened a second time unless it is released by someone who has the key for the panel where the letters are taken out from.

The goal was to make this box smart, that means

  1. get a notification if a letter is thrown into the letter box
  2. get a notification if parcel is put into the parcel box
  3. see if the parcel box is locked or unlocked

Luckily I recently had a good occasion to get a cable (network, CAT. 6 I think) from our house to the box, so I had 8 wires to use for this and no need to do this wirelessly.

To get the status of the parts I am using the following components:

  • 24V transformer
  • Shelly i3
  • normal window contacts (NC)
  • some glue and double-side adhesive tape

The window contacts are mounted

Each one is cabled with one common “-” wire on the one side
and with individual “+” on the other side.

At the other end of the cable the Shelly i3 is wired as shown below:

(Ok, there is some potential for optimisation, an accurate wiring is on my todo list :slight_smile: )

With this installation one should be able to see the status in the web interface of the Shelly.

As I am using mqtt, I configured my mqtt server and a separate queue for the parcel box.

On the HA side there was only some configuration needed:

- platform: mqtt
  name: "Shelly Garten Briefkasten"
  state_topic:   "shellies/garten/briefkasten/input/0"
  payload_on: 1
  payload_off: 0
- platform: mqtt
  name: "Shelly Garten Paketbox"
  state_topic:   "shellies/garten/briefkasten/input/1"
  payload_on: 1
  payload_off: 0
- platform: mqtt
  name: "Shelly Garten Paketbox Riegel"
  state_topic:   "shellies/garten/briefkasten/input/2"
  payload_on: 1
  payload_off: 0

With this configuration HA knows about the state of the sensors and can

  • trigger telegram notifications via chatbot
    2021-11-03 12_08_28-Telegram (1)
  • show an actual status on our dashboard
  • trigger some additional actions if the parcel box locked and someone else want to leave something here (also on my todo list)

Actually I am waiting for the Shelly i4 (which might be launched in the next few weeks) to get my door bell at the fence also wired into HA. In the mean time I might use a spare Shelly 1, let’s see how much time I will find in the next few days.

If you like this idea feel free to like it or even vote for me at the Shelly contest → Project 69.


Nice write up thanks :blush:

I’ve been thinking about doing something like this or buying a ready made smart box and integrating it.

One of the most important questions for me is how many delivery drivers actually will use a box rather than just dropping it on the front door step and runnng away? I like your simple operation - I’ve seen some boxes that have a button to request delivery and a remote unlock. I can’t ever see that working! So a simple open and lock would seem to be the way to go with a remote sensor to tell when it’s been used.