Using Sonoff SV w/ Tasmota to read Soil Moisture

Very recently I discovered that Tasmota can also work with sensors.

After I discover that, I thought: Ok, Sonoff SV I use, for instance, to activate my electric solenoid 12V valve to activate watering in the garden, so if I could connect sensors to it, I could stop using an ESP32 I have with outside temperature and humidity as well as soil moisture and rain.

I’ve noticed it’s very straight forward to plug a DH11 or DH22 to a Sonoff SV and I have it already working with that.

But I’ve tried in so many different ways to make it work with a basic Soil Moisture sensor and I was not able to do it.

I also found out that Sonoff SV is supposed to have a GPIO17/TOUT/A0 pinout, but nobody online seem to have found it yet…

This basic soil moinsture sensor have actually both outputs: analog and digital.

So using the digital output, I should be able to use any of the GPIO4, 5 or 14 from the Sonoff SV, but I simply can’t make it work. :frowning:

So, has anyone ever put a soil moisture sensor into a Sonoff SV with Tasmota on it? If so, how?

If not, do you have any idea how this could work?

Or should I get a different sensor to connect to Sonoff SV?

Any help will be much appreciated. :slight_smile:

Maybe it is a good idea to ask the tasmota community, because this is specific tasmota question and not an openHAB question.

But as long as the GPIO17 is somewhere on the board it should be possible to attach the soil sensor and then configure the pin in tasmota


Thank you, it makes sense and I actually just did that. But I’ve also posted here because I use OpenHab for some years now and eventually someone could had come accross this here. :slight_smile:

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Resistive moisture sensors are affected by corrosion. Sonoff has the MS01 sensor that connects directly to the TH10/TH16 and can be installed with a 5m extension cable. Why not use that instead ?

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Thank you for your answer. Yes, I know that, but I wanted to use the Sonoff SV because it operates with low voltage and so I can work with the 12V and 24V solenoids.

Another suggestion, use the TH10 to switch the transformer of the solenoids, and SV’s for the solenoids. I’m doing something similar in my irrigation system.

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Using a Sonoff 4CH Pro R2, that’s actually a very clever idea to control multiple electrovalves without having the need of multiple devices.

Obviously that it also means this is a single point of failure.

Anyway, it only compensate if we will control 4 valves. Less than that it’s cheaper to buy Sonoff SV and control them individually.

PS: Pelo que vi das imagens, é português, mas respondi em inglês na mesma para outros poderem ler. :slight_smile:

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Uso 3 electroválvulas, o 4º relay do Sonoff é para o transformador :wink:

Each case is a case. A single Sonoff may be a spof but this allows Tasmota rules to manage the full irrigation cycle and OH only adjusts some parameters (this will be version2 of my project). It’s also possible to pair a remote with the 4CHPRO and initiate the cycle with no OH intervention (I hate to be 100% dependent of OH).

Nothing obliges the TH10 to be used for irrigation. It can manage any other device near the garden so that the MS01 sensor can be connected. I’m thinking about controlling garden lights with it.

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