More fiddling with water

After a few more weeks of testing, I've found some new values, and edited the script more.

1.  Originally, I had thursdays blacked out because the Yard guys come that day.  It was simply blacked out via cron. I noticed in the hard summer, this was too harsh, and the lawn would dry out too much that day.  Instead, I've written blackout hours into the script, so just the 8 hour window is blacked out.
2. I've added day/night sensing via the LUX sensor.  I also have a day trigger number (21) and a night trigger number (19). This gives a slight preference to watering at night, while still keeping the lawn safe from dryout during the daylight hours.
3. I had to bump the time each valve runs to 900 and 600 seconds for the primary/secondary rows.

All these changes, and the lawn is starting to green up quite a bit.  I think I've almost nailed it.

Some future ideas:

1. Fix the ground temp probe, and if the ground is frozen, don't water.
2. Maybe don't water if it's super windy?  This is semi-debateable, because the high wind dries the lawn out fast.

Got to keep fiddling.  Maybe I'll go automate something different for awhile.  It's working well so far.