MQTT,USB,RS485,GPIO between arduino and RPI?

I have 1 arduino which reads temperature and motion for each room in my flat(doing this way because rpi does not have analog input), then i have 1 arduino running running my bar mechanism, then i have one arduino controlling the led lights in my kitchen.

The sensor arduino is next to rpi, 20cm away, the other two are 20m away, but i have 4 wire running to them as well as ethernet outlet not far from them. Since I have cable to to the arduinos, and since they need power i dont see the point of using wireless communication to the rpi, am I wrong here?

The question is then how should I connect the arduinos to the rpi, should i use i2c, serial, usb, ethernet,rs485? It would be nice if I dont have to run out and get a lot of bulky ethernet shield, but can keep using the arduino nano.

Can anyone give me cons /pros for differnet solutions? and also point me to a webpage with the setup?


Maybe Souliss or MySensors (RS485 currently in testing stage) may be something for you.

Yeah been looking at those, dont know which ones are better than the other, it seems like more people are using mysensor, but thar souliss is easier.

Did you find any solution?

The one closest to the RPI i would use USB (or add a analog i/o expander to the raspberry pi). the other two. i would suggest to use RS485. but you do get extenders that enable you to use i2c over those distances.

you could even use mqtt and network by adding a network shield to them ?