Secure Intenet Delivery Cabinet

After finding an Amazon parcel dropped in the rain in a muddy patch in the garden when I was unavailable to answer the door I decided to provide a secure cabinet for deliveries to my home that would not fit through the letter box..

The shed is only ten feet away from the front door, so was the obvious choice. The basic cabinet took me about two hours to make with a circular saw and an electric screwdriver. I spent another three hours improving the cabinet to make it more weather proof and activate a remote warning light inside the house.

Shed - already had one
2 x 400mm surface mount gate hinges (DIY Store)

12 x coach bolts (DIY Store)

1 x handle (DIY store)

1 x Magnetic Door lock kit ( ebay:

https://www.ebay.co.uk/itm/Electric-Door-Lock-Magn...

9mm plywood (500mm x 720mm)

9mm plywood (720mm x 420mm) x2

9mm plywood (420mm x 500mm) x2

3.6m 37mm square smooth planed whitewood

Sundry wood screws

Additional electronic components for indicator light:

2 x Wemos D1 Mini Arduino clones

1 x 12v Relay

1 x Push button test switch

1 x 1kOhm resistor (for AM2302)

1 x AM2302 Temparature and Humidity sensor

1 x LED

1 x 220 Ohm resistor (for LED)

I started by adding battens to the inside of the opening to hold the shed planks together and then cut the opening with a jigsaw, just above the batten at the lower edge of the shed side and inside the battens I addded. I used the gate hinges to reattach the panel I had cut out as the door, discarding the supplied screws and replacing them with short coach bolts to prevent the door from being removed from the outside.

I then built up the cabinet inside using the 9mm plywood pieces and the 37mm square length of wood to make the corners, screwing everything together with wood screws.

After constructing the cabinet I found rain occasionally got in at the top and bottom. I added an aluminium weatherstrip top and bottom to guide water running down the shed side off to drip down. There's still a tiny amount of moisture getting in when heavy rain blows into the door edges.

The bottom of the cabinet is loose, sitting on the battens at the bottom. I have made springs out of dowels that support the floor just above the rear batten. These allow the microswitch I installed to remain open when the cabinet is empty. When an item is placed in the cabinet, the floor is pushed down against the battens and closes the microswitch. Closed, the circuit energises the magnetic lock.

At this point the cabinet worked and latched closed when an item was placed in it. However, I only knew a delivery had been made when I went to the shed to check if the cabinet was locked. I needed a remote indicator.

I added a relay to the circuit. This is normally open, closing when the lock is energised. I already have an Openhabian home automation server runing on a Raspberry Pi, so I added a pair of Arduinos running Tasmota into the system. The Arduino in the shed sets a switch item in the home automation when the relay contacts close (Cabinet locked). A second Arduino on my desktop lights a light when the switch is closed.

Just for fun I added a AM2302 temperature and humidity sensor to the shed Arduino circuit.

On my desktop I have a second Arduino to display the status of the cabinet with just an led indicator wired into it. Some simple rules coded in Node Red in Openhabian sets the light on my desktop to On when the cabinet lock is activated.