Two Controllers - Isolation - Rain Sensor?


#1

I have two controllers. A rachio gen 2 and another brand. I’d like to have both but not run them both at the same time. In other words, one will be disabled at all times.

I read the article about needing to isolate the common and have ordered the part. Greatly appreciated on the writeup and the link to the isolator part.

Can a rain sensor be shared across the two? Any special wiring required for the rain sensor to work on both controllers?


#2

@beedix, there would be a similar issue to shared commons with shared rain sensors as there is current running through the rain sensor. I’d either a) just connect the rain sensor to the “other” brand and let the Rachio use the reported precipitation or b) buy a second rain sensor of the “other” controller.

One theoretically could put a relay in-line on the rain sensor and use the relay to switch power from the other controller. In this situation, the relay would be energized almost all of the time and I haven’t been able to find the maximum duty time for the relay coils. If the relay coil doesn’t get hot after being on for a few hours it might be fine. A relay would cost around $8. So at $16 for a rain sensor it might be easier to just put two rain sensor in, rather than having a relay to play with.


#3

@DLane good point. I think i’ll just mount a second rain sensor. Much appreciated!

Hopefully i can run the Rachio only soon. I think some of the features I’ve held out for are implemented now. We shall see!


#4

You may be able to use ifttt.com to setup a software link between rain sensor on the “host” controller and the rain delay on the second controller. Something like this:

Cheers,
Gene