This is my first prototype Home Automation.
There are two buttons - ON/OFF.
Four relays, one door sensor, reset button are connected to the Arduino UNO.
All this is in the old PC case.
Raspberry Pi 2B
Two modules are connected to Raspberry Pi
There is BMP180 (temperature, pressure), it’s ready for DS18B20.
There is MCP23008 modul.
Thera are MCP23008 and level converter and eight input/output.
(Arduino Mega is ESP8266)