I want to know the state of an external Relay connected to my Raspberry-Pi. Basically if there is current flow or not in A-B. A-B should be connected to R-Pi.
I am not sure how to proceed even though I found many similar topics (example: Detect if current is flowing). I don't know if they are compatible with my problem as I don't want to fry my devices ^^"
So the questions are:
- How to connect the relay properly to R-Pi
- What extra components are needed
- How to detect the relay status ON/OFF
I have 2 Honeywell wireless thermostat with their corresponding relay boxes which are meant to be used in stand alone mode as follows, but only 1 can be connected to the boiler:
In the new setup, the goal is to use a Raspberry-PI to coordinate between the two and control the boiler using my own relay and logic (example: only turn-off when both Relays are off, ...) -please excuse the crude diagram-
All components are within 1 meter distance.
I tried to avoid overwhelming you with extra details. But it seems inevitable to have the right answer. Anyhow, the scheme below shows and overview of the overall installation:
- We have 2 floors each with similar components: relay (controlled remotely), 3-way valve and a pump
- the relays trigger the heat request
- the RPI is coordinating how the different components behave based on that trigger (logic yet to implement but that part should be ok)