On: ESPHome

[epcoa]

> generic RS-485

You can already hook up an RS-485 transceiver to the UART ports and use it today with the UART driver. Esphome also has a Modbus controller component. What are you referring to by “generic” RS-485 that isn’t available already?

[cyberax → epcoa]

RS-485 is a shared bus, so you need to use some kind of a protocol to arbitrate access, and to make sure you don't flash unintended devices.

BACnet is one example, but other protocols can work too.

[epcoa → cyberax]

https://esphome.io/components/modbus_controller.html

[cyberax → epcoa]

It doesn't allow firmware updates over modbus. The same would also apply to Zigbee.