Setup for optical sensor


Has anyone used the optical sensor? I used it with my previous irrigation system and it worked really well. I connected the sensor to Iro and it appears Iro is working with the sensor however when it rains I get a notification it’s raining and when the rain stops I immediately get a notification it stopped raining but the schedule doesn’t get delayed after the rain. Those are great sensors and I’m hopping their is a fix for this. I have the 2 rain sensor wires connected to R1 and R2 and the 24vac to R1 and COM for power.

Thank you,

Need help with optical sensor

@Ljiddou, this optical sensor looks really cool!

Just curious, what type of controller did you have before the Iro?

The Iro is designed to take rain sensor inputs and interrupt the common to prevent the Iro from running. It will not change the schedule.

I think the sensor is working as it’s suppose to with the Iro. I’d need to understand how your old controller worked with the optical sensor to reschedule watering times…

Happy to investigate but not promises we can replicate.

Hope this helps.

Best, Emil


You might want to check that it is set to “Irrigation Control”, Mode 4. DIP switch 7 on. Other modes, such as Mode 1: “It’s Raining” mode will enable when rain is detected and disable immediately after rain stops, as you are describing. Mode 4 will estimate rainfall amounts and simulate a drying time and indicate rain stopped after it has estimated dry time. Mode 4 can be customized to allow longer or shorter “dry” times. See more here:

These are pretty amazing sensors, although I do not currently use it for irrigation purposes.


@njenslin, great feedback! Thanks for sharing this. I overlooked that in the user manual. Just curious, where did you learn about these sensors?


@emil I had a friend who had some connection to them, he told me about it when I was working on a pool cover that would automatically open and close based on certain conditions. That project never really panned out as there are apparently some glaring safety concerns with a pool cover that closes automatically, but that’s a different story.

On another note, apparently I missed all the 2.0 Beta talk last week. If you still need any additional testers for Android, let me know, I’d be happy to help.



Next week I hope to bang the Android beta drum.



Man now I really want to get one of these! I think I would want Rachio’s blessing first though…


Leaving that up to @emil :wink:


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@Striker169, I’ll need to order one to test it. @Ljiddou, maybe you can validate the sensor’s operation and functionally for us?

Thanks, Emil