OK, testing has started.
This morning the low was 44 degrees F ( http://welserver.com/WEL0043/ - Dallas weather).
My Iro2 issued a Device Update "Rain sensor activated." statement today at 1:52 AM. This means it was 50 degrees F at 1:52 AM.
Later this morning, at 8:49 AM, my Iro2 issued another Device Update "Rain sensor deactivated." statement. This means is was back up to 50 degrees F at this time.
My 'Flex Daily' automated schedule is set to run at 10:15 AM any day.
Rachio cloud processing occurs 65 minutes before schedule start. It does a bunch of algorithmic processing at this moment, including:
First looking at:
1. Is the Iro2's Rain Sensor option turned on, and if so, is the connection opened up between Iro2 terminals S1 and SC? (Here's where I have my customized 'freeze' sensor connected.)
If the answer to these two questions is 'yes' then the upcoming schedule iteration is canceled. If the answer to either question is 'no' then processing proceeds further, using the 'connected' weather station:
- Is it raining now?
- Is it 32 degrees or less right now?
- Is the forecast to have X or more inches of rain today (I don't know what X is)
If the answers to any of these 3 questions is 'yes,' then again the upcoming schedule iteration is canceled.
What this means for me is that if my 'freeze sensor' is not 'off' (connection between S1 and SC not closed) before 9:10 AM, 65 minutes before Rachio cloud processing begins, my schedule is skipped for the day (no watering).
What this also means for me is that zone moisture content accumulation continues. Thus if my freeze sensor gets in the way of a day's watering, the watering amounts will be automatically adjusted for the next day.
So what happened today, just a few minutes ago? In the Schedule Updates section Rachio cloud processing just posted, right on time at 9:10 AM: "3309 Schedule with Zones 10, 3, 7, 6 scheduled to run at 10:15 AM" Perfect!
Yippee! I think this custom 'variable temp setting' freeze sensor implementation is going to work!
What I really like about this is that I can absolutely be sure my Iro2 will never water during freezing conditions, regardless of choosing the wrong weather station to connect to, weather station problems itself, etc. My municipality fines heavily for watering during freezing conditions.