I’m working on a project to control and automate the watering system for the greenhouse and some parts of the garden.
The plan is to split the system in two independent parts, each one with its own ESPHome.
One ESPHome will sit at the “pump station” and control the water valves, measure the level in the rain water barrel, stop the pump at low level and so on.
The other ESPHome will sit inside the greenhouse and measure the climate in the greenhouse and the plants.
When the plants need water I would like the “greenhouse ESPHome” to be able to communicate to the “water tank ESPHome” to turn on the water valve.
As I want this to be as robust as possible I will not use any wireless communication for functional signals, only for monitoring and settings.
That means the signals between the two ESPHome nodes must be hardwired.
The simplest way is of course to just tie a few I/Os between them, but then I know myself and will later think “it would be cool to have that signal and nice to pass that value between”…
With that in mind we now at last are coming to my actual question:
What is the best and easiest way to pass let’s say 5-10 signals and values hardwired between two ESPHome, and maybe also with some error correction in mind? The distans between the ESP will be about 5-10 meters and there is no speed requirements.
- Shift register?
- UART Serial?
Any wise and clever ideas are appreciated.