My house now lets me know when I have mail delivered through my letter box. This is mainly electronic components from China. It tells me “You’ve got mail” in a Stephen Hawking voice.
It takes a few Raspberry Pi servers to achieve this:
The enOcean sensor on the letter box is driven by a solar panel and so needs no power supply and is maintenance free – no batteries to change.
The EnOcean gateway Raspberry Pi receives the wireless signal from the letter box sensor and publishes it to the Raspberry Pi Mosquitto MQTT server. The node-red server has a flow that subscribes to the MQTT message and calls the HouseControl server via a TCP socket, which does the voice synthesis.
So now, nothing is left lying on the hall floor for even a few seconds. I get to play with my toys as soon as they arrive.