Before I started this project, I already had an Arduino in my corridor, which controlled some LEDs based on a PIR sensor.
So the next step was to add features to it and integrate it into my home automation.
First, here is an image of the current assembly, which is housed in a commode in my corridor.
The wires go to two PIR sensors, one servo motor and one led strip. With this, the Arduino is able to detect movement and light up the led strip. For the PIR sensors, I made some nice small mounts out of aluminium and placed them on top of the commode.
The Arduino also sends movement events over serial to the ESP, which logs everything to the central server on the Raspberry PI.
But the main feature is, that the assembly can receive commands over 433MHz from wall switch remotes and forward them to the remote outlets attached to the ceiling lights in all rooms (currently it's just in my bedroom). So it is acting as a bridge between different 433MHz protocols. The ESP can also receive commands over WiFi and get the Arduino to send 433MHz commands, so I can also control the lights from every device connected to my network. Besides that, the arduino can forward received 433MHz commands to the Raspberry PI, to trigger custom events or commands.
Another feature is the servo, which can trigger the button for the release buzzer for my front door.
This enables me to open the front door with my smartphone or a 433MHz remote. When using the remote, the Arduino asks the Raspberry PI, whether it is allowed to open the door before pressing the button. Currently, the Raspberry PI never prohibits the opening, but I can easily add logic to it.
Because I think I am not allowed to alter the interphone, I had to realise my plans with the servo. I also thought that it would be a good idea, to be able to easily remove my addon, so I made a custom servo mount for it. To match the style of the big white box, I will also paint it white soon.