I had high hopes for this sensor but it is erratic and I'm really not confident in the humidity readings. Battery dropped to zero quickly, but it still keeps humming along. It also took a break from supplying readings for a period but then re-started.
I have 3. Two were in the lawn and one in an orchid pot.
Turns out our local foxes love to chew on them and I would regularly find the lawn ones with extra bite marks and tossed into the garden. Some nice video of it.
The orchid one is pointless as my wife barely waters it and it's dry most of the time.
Becuase I only have 1 working one left there is no way for me to test them for variance/accuracy against each other, but one of rhe lawn ones was a definite dud, the other might have been reliable but without buying more I won't be able to tell.
I finished my garden watering system this summer and also rain sensor. Will wait until next spring before ordering more soil moisture sensors and giving it another go.
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Long-time lurker here but thought I'd post for the first time since I have some results. I ordered one despite some of the misgivings people have noted. Mine seems to have been working reasonably well the last two weeks with it outside in a container. Had a rainfall over night and humidity spiked along with the rainfall and even showed a heavy spike when the rain came in harder in the middle of the storm. I had a relatively smooth exponential decay drop-off in humidity from about 80% after the storm to 59% today with no rain in between. It looked very much like some of the other sensors I've used, however those other sensors were bluetooth via Tuya hub and I suddenly had updating issues, hence the continued search for inexpensive sensors that would work directly with Hubitat.
I just watered today after a week and I got an instant 100% humidity that dropped off nicely over the last 5 hours. I deliberately watered with warmer water to see how it would affect temperature as well. I just started using WebCoRe in Hubitat to graph, but it seems to only show a max of 1 week results in graphs:
The small little spikes and dips in humidity are 1% spikes, inconsequential when it comes to watering plants outdoors.
I don't know if others are experiencing this, but I find with these capacitive sensors, after any adjusting or reinserting in the soil requires watering well after and not touching it to get the the best results.
My soil mix tends to be composted fir fines/composted fish products with some perlite/sand and/or fine bark mulch.
I've now ordered another 2, since this one seems to be working well enough for my needs and planned automations. Will see how reliable it is over the winter before building out some irrigation rules next spring/summer.
Update: Since graphs only show a week and I can't show the previous humidity curve, this is the graph ~9 hours after watering:
And the 1 Day View:
Update 2:
And the 3 Day View:
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After yesterday's test with warm water, the sensor with the blue silicon wrap seems to take air temperature. I went searching to see if I could find one that includes soil temperature.
Found an "updated" version of the tube style Tuya sensor that now includes:
- Air temp
- Soil temp
- Light intensity (65535 Lux range - a little more useful to outdoor/very bright conditions)
- Humidity
**Update: do not buy from this seller if you want a sensor with both Air and Soil temperature measurements. They confirmed their listing was wrong and the manufacturer "upgraded" the sensor to only 1 soil temperature reading as "customers were confused" by the two readouts.
I've since ordered a "4-in-1" sensor from a different seller that insists theirs provides 2 temperatures but I have not received it yet.
I've ordered one to try. Has anyone tried one of these?
The soil sensors have been reporting without glitches. You can see when my wife watered the flowers.
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@kkossev is it possible to add voltage ranges for the device driver to allow the use of alternate battery chemistries? I found some cheap rechargeable AAA NiMH batteries meant for outdoor solar lights. They've been working well so far but they always show 0 battery. The two new sensors I've bought have arrived and those will be on alkaline as a comparison.
Thanks
@user4286 Two more sensors came in so I installed them in nearby containers to see how consistent these sensors are.
Soil sensor 1 and sensor 2 are in very similar soil as I mixed and potted them recently, with sensor 2 more sheltered from rain.
Soil sensor 3 is in a container with somewhat similar soil but also in a container that has had several years of tree growth - the top layer of the soil is filled with fibrous roots.
After installing the two new sensors, my Sonoff SNZB-02P also came in, so I plotted it's data as well as a comparison since reviews have said that this sensor is quite accurate. (Of course, it only measures air humidity though, so the only direct comparable is temperature.)
All sensors are roughly within 3 meters away from each other.
As far as I can tell, these soil sensors seem pretty consistent:
- Temperature is pretty much within 1C for all sensors.
- Soil humidity tracks nicely as expected after watering in and after rain.
- The two similar-soil containers (sensor 1 & 2) show more similar absolute humidity values than sensor 3, which was also expected.
- The drop in humidity after watering/rain looks correct, with an expected "exponential decay-like" behaviour showing the soil's water carrying capacity.
Soil sensor 3 is the farthest away from my Zigbee network and behind a low wooden fence. You can see in the graph that it dropped off after less than a day. I added another router (dimmer plug) nearby and re-paired it. Although it initially connected to this new router, it seems to have moved back to being connected to the farthest router possible. But it hasn't lost connection in the last few days, so hopefully it isn't going to be a problem.
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Thought I'd update regarding my previous comment on this blue silicon wrapped sensor's sensitivity to being disturbed (and these capacitive sensors in general).
I was moving my container around, tilting it while lifting several times and while the sensor did not dislodge from the pot, I definitely saw a drastic change (drop) in the humidity readings.
Simply reinserting the sensor returns some of the humidity but from my experience, the most accurate/consistent results when performing any repositioning of the sensor require it to be watered in again:
If you water after, it will follow the pocket of humidity in the soil as expected as shown in the graphs in the previous posts.
If its a larger pot, you don't need to water the whole pot nor do you need a ton of water - just enough water around the base of the sensor so that the soil reforms and interacts tightly with the blade of the sensor:
Best to set it, water it and don't touch it.
