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I've really liked my RainMachine sprinkler controller. It only requires internet connectivity to download weather reports; all other functions are available via

I've really liked my RainMachine sprinkler controller. It only requires internet connectivity to download weather reports; all other functions are available via LAN. Being able to turn the sprinklers on via the phone is incredibly useful for verifying repairs, finding leaks/clogs and aiming spray patterns. And it reduces water usage by deferring watering if enough rainfall has occurred.

tk75x 5y ago
Sprinkler systems have for years included a rain gauge that trips a signal if there is water in the tube and turns off the lawn watering. The smartphone controls would be convenient but only for very specific situations and not 99% of the time you're using the sprinkler system.
KallDrexx 5y ago
Why do you need internet connectivity for any of that? My sprinkler system has a sponge hooked up to the roof. If the sensor detects the sponge has too much moisture it doesn't turn the sprinklers on, because that means the soil is still saturated from recent rain.
- dharmab 5y ago
  How long is watering suppressed by the sponge? Does the controller "remember" that the sponge triggered a few days ago when the watering day comes around?
  - KallDrexx 5y ago
    It has a permanent sensor on there, so the sensor doesn't remove the signal to not turn the automatic sprinklers on until you press the manual bypass button, or until the sensor no longer detects moisture above the set threshold. When the controller hits the scheduled time it checks with the sensor unit, if the sensor says there's too much moisture it doesn't turn them on.
    - dharmab 5y ago
      Nice, so it holds water just like the earth. Makes sense.
      - tharkun__ 5y ago
        I wonder if that actually works that well. Especially with black roofing tiles which get quite hot. Compared to the hopefully shaded by the plants themselves soil. If your plants are sometimes shaded by trees depending on time of day the sponge will also probably fail you because your roof is more likely not to be shaded at all in many places for fear of overhanging tree limbs or roots being a danger to the house over the long term. Though it would be good for saving on cooling costs/energy use but then the sponge stays too wet vs. the soil. I'd go for a soil moisture probe. That checks whether the plants really need the water, not whether a sponge with a "different reality" than the plants is dry. Weather report data is cool though. Though you can't trust the weather report only, you can nicely combine the data from a soil probe (a "multi zone" system with a probe per zone would be great, probably easy to program with a Pi) with expected rain but an override via the soil probe if it actually didn't rain. Since the OP said sprinkler I'm sort of thinking lawn though which I think should just never be watered at all ever. Waste of water just to look nice. And yes our town actually prohibits watering of lawns in summer. And for plants drip irrigation is better than sprinklers but hey, if you have a sprinkler system already go for it.
        dharmab 5y ago
        > I think should just never be watered at all ever Depends on the situation. My town wants us to water less frequently, but keep our grass from drying out to prevent a fire hazard and soil erosion. I do wish my front lawn was smaller to be sure. I'd be happier with more garden beds or garage/shed/workshop space.
        tharkun__ 5y ago
        Caveat: I don't live in a fire hazard zone so take this with a grain of salt. Wouldn't it be better not to plant any grass if it's that bad where you are? For soil erosion planting something else sounds more adequate. I do see a problem with septic fields. Can't plant anything else that I know of on those but grass. If you do know of something let me know and I'll plant it on mine instantly lol.
- mhalle 5y ago
  A forecast driven watering algorithm can look for rain in the immediate future, rather than the current state of the ground. It can also change the duration of watering based on temperature and relative humidity. RainMachine does that while only consuming weather data. You also have the option of turning that off and just using wireless control of the sprinklers, which as the GP says is extremely handy.
- twic 5y ago
  Is there a reason why the sensor is in a sponge on the roof rather than in the soil?
  - dharmab 5y ago
    If it were in the soil, the sprinkler system would suppress itself in a feedback loop unless you had an intentional brown spot for the sensor.
lostlogin 5y ago
I was too cheap to buy a flash system and made one with a tp-link smart plug and a solenoid. It can be activated by the mostly-ok tp-link app, but is also automated in Home Assistant. It turns on for 10 minutes in summer. By wiring the solenoid correctly, it fails to an off state. It’s basic as all hell and works really well.

tk75x 5y ago

Sprinkler systems have for years included a rain gauge that trips a signal if there is water in the tube and turns off the lawn watering. The smartphone controls would be convenient but only for very specific situations and not 99% of the time you're using the sprinkler system.

KallDrexx 5y ago

Why do you need internet connectivity for any of that? My sprinkler system has a sponge hooked up to the roof. If the sensor detects the sponge has too much moisture it doesn't turn the sprinklers on, because that means the soil is still saturated from recent rain.

dharmab 5y ago
How long is watering suppressed by the sponge? Does the controller "remember" that the sponge triggered a few days ago when the watering day comes around?
- KallDrexx 5y ago
  It has a permanent sensor on there, so the sensor doesn't remove the signal to not turn the automatic sprinklers on until you press the manual bypass button, or until the sensor no longer detects moisture above the set threshold. When the controller hits the scheduled time it checks with the sensor unit, if the sensor says there's too much moisture it doesn't turn them on.
  - dharmab 5y ago
    Nice, so it holds water just like the earth. Makes sense.
    - tharkun__ 5y ago
      I wonder if that actually works that well. Especially with black roofing tiles which get quite hot. Compared to the hopefully shaded by the plants themselves soil. If your plants are sometimes shaded by trees depending on time of day the sponge will also probably fail you because your roof is more likely not to be shaded at all in many places for fear of overhanging tree limbs or roots being a danger to the house over the long term. Though it would be good for saving on cooling costs/energy use but then the sponge stays too wet vs. the soil. I'd go for a soil moisture probe. That checks whether the plants really need the water, not whether a sponge with a "different reality" than the plants is dry. Weather report data is cool though. Though you can't trust the weather report only, you can nicely combine the data from a soil probe (a "multi zone" system with a probe per zone would be great, probably easy to program with a Pi) with expected rain but an override via the soil probe if it actually didn't rain. Since the OP said sprinkler I'm sort of thinking lawn though which I think should just never be watered at all ever. Waste of water just to look nice. And yes our town actually prohibits watering of lawns in summer. And for plants drip irrigation is better than sprinklers but hey, if you have a sprinkler system already go for it.
      - dharmab 5y ago
        > I think should just never be watered at all ever Depends on the situation. My town wants us to water less frequently, but keep our grass from drying out to prevent a fire hazard and soil erosion. I do wish my front lawn was smaller to be sure. I'd be happier with more garden beds or garage/shed/workshop space.
        tharkun__ 5y ago
        Caveat: I don't live in a fire hazard zone so take this with a grain of salt. Wouldn't it be better not to plant any grass if it's that bad where you are? For soil erosion planting something else sounds more adequate. I do see a problem with septic fields. Can't plant anything else that I know of on those but grass. If you do know of something let me know and I'll plant it on mine instantly lol.
mhalle 5y ago
A forecast driven watering algorithm can look for rain in the immediate future, rather than the current state of the ground. It can also change the duration of watering based on temperature and relative humidity. RainMachine does that while only consuming weather data. You also have the option of turning that off and just using wireless control of the sprinklers, which as the GP says is extremely handy.
twic 5y ago
Is there a reason why the sensor is in a sponge on the roof rather than in the soil?
- dharmab 5y ago
  If it were in the soil, the sprinkler system would suppress itself in a feedback loop unless you had an intentional brown spot for the sensor.

lostlogin 5y ago

I was too cheap to buy a flash system and made one with a tp-link smart plug and a solenoid. It can be activated by the mostly-ok tp-link app, but is also automated in Home Assistant. It turns on for 10 minutes in summer. By wiring the solenoid correctly, it fails to an off state. It’s basic as all hell and works really well.