What is the best wired way to communicate between multiple NodeMCU ESP8266 boards for home automation.
Every room should get at least a light, temp, PIR and xx relay modules to switch things on and off.
To connect all these sensors the GPIOs from one NodeMCU are sometimes not enough.
To reach this goal I planned to install in every room one NodeMCU as gateway and multiple NodeMCU as nodes for my sensors. The gateway will receive and forward information from/to my openHAB center via MQTT messaging.
I thought to use an RS-485 2-Wire connection between my sensor nodes and the room gateway. The gateway from my room will be connected via wifi or wired cable to my network.
I2C seems more to be for communication directly on PCBs or only short wiring.
Do you have any suggestions for me, is my plan possible? Any better ideas?