Outstanding video. Thanks for sharing your explorations in calibrating DIY capacitive soil moisture sensors. We are long time users of Teros 12 sensors and consider them the gold standard for capacitive (indirect) volumetric soil water content measurement.
@ModestMaker
3 ай бұрын
Thanks and yes- the Teros sensor is what my colleagues at the University of Arizona are using. I wish I could get my hands on one to explore- a bit too pricey though for a backyard citizen scientists. I still think there’s a lot we might determine from temperature as an affordable analog : kzitem.info/news/bejne/la-czn6Ifmaid4osi=IPuJ9EaXba2qnj67
@cpfglobalagronomics6162
3 ай бұрын
@@ModestMaker Dielectric permittivity is a decreasing function of temperature. Generally for subsurface probes we don't take this into account as diurnal soil temperature does not fluctuate to the same degree as air temperature. To estimate available water capacity including the permanent wilting point, the soil water characteristics calculator may be helpful to you www.ars.usda.gov/research/software/download/?softwareid=492&modecode=80-42-05-10 Estimates of percent sand, silt, clay, bulk density, organic matter, and salinity for your soil are input values. Bulk density is easy to measure, percent sand, silt, clay can be obtained from USDA-NRCS Web Soil Survey for your soil type (preferred) or estimated via column sedimentation. Since you're located in an arid region salinity (saturated extract) may be important. Check with Web Soil Survey or measure this with an inexpensive meter. And good luck with your adventures in capacitive soil moisture sensors.
@ModestMaker
3 ай бұрын
Thanks! An ARS calculator for wilting point- I love it. Agreed- not too much temperature variance at depth, but definitely a diurnal signature a few inches down. io.adafruit.com/biod101/dashboards/soil-experiment-ambient-shade. Maybe the first few inches can tell me something, although I agree rooting depth is the key. It’s fun to measure all this stuff anyway. kzitem.info/news/bejne/kpyB1ayieoqSdIosi=pQZ5eV6Q4TPdMJfG
@wayneyeo186
3 ай бұрын
Excellent video, thank you for the time to produce the experiment, document it, and put up a video of your results. I am trying to come up with a sensor system to help indoor watering, specifically in the winter. I have done a ton of reading, youtubing etc, and so far, not found something that produces consistent results over longer periods of time. Resistive sensors deteriorate too quickly, capacitive sensors have promise, but the trick is to find a high quality one. There may be other solutions, but so far, I have not found any.
@ModestMaker
3 ай бұрын
For what it's worth, I've been working with the University of Arizona on an irrigation control system that uses Teros 12 sensors (metergroup.com/products/teros-12/). Working with a student, we managed to get these to interface with an ESP-32-S3 for controlling a suite of irrigation control valves (solenoids) at a research site. The Teros 12 sensor supports the SD1-12 communication protocol for which there is an Arduino Library. Since the code and project are not my own, it wouldn't be appropriate for me to share that on my channel but I will confirm it's doable. I have reached out to Meter Group asking if they would donate a sensor so I can produce a formal tutorial on how to do this for the benefit of others, but they declined. The issue is the sensor is costs about $258 which is something I can't afford, but it is an alternative you might explore.
@wayneyeo186
3 ай бұрын
@@ModestMaker the Teros 12 sensor is highly unlikely to pass the better half approval test. But I will check into it. I was planning on building at least 4 sensors, but more likely 8, as we have winter storage in 4 different location. We have a large collection over wintering. I am fine with a sampling technique in each area. Thinking a large pot and medium pot sample would get me close enough for my objectives. I want each one to be wireless, so I can remote monitor them. As a retired professional coder, software will not be an issue. I am new to esp32s. I have done a little bit of micro PLC work, so building the hardware should not be an issue. I love the work you have done. Very nicely executed !
@ModestMaker
3 ай бұрын
Thanks. My experience has been that the capacitive sensors do not hold up to the elements very well over time. Here is the full playlist : kzitem.info/door/PLqJ5k4cakypy1E4J_tvEiD0kpFK1tGY3D&si=r4vya3sAPACIluSV
@RonnieTheSim
Жыл бұрын
Excellent! In the "maker" world we sometimes call a build successful if it even survives long enough to log some data. Suppose it does -- now, about that data? I clicked on this video looking for 'pro tips" about a specific device and its application. But in teaching that, @Modest Maker is also demonstrating the thoughtful approach of a skilled integrator. Prototypers of all kinds on whatever platform, watch: this is how one coaxes a component to reveal capabilities beyond what its pricetag or (non-)documentation might suggest. Yes please, OP @Modest Maker, I will enjoy getting your test data when you upload it!
@ModestMaker
Жыл бұрын
Of course - updating description now with link to spreadsheet. I removed some confusing notes from preliminary tests that weren't relevant, but you'll find other calculations and references in the spreadsheet that might be useful: docs.google.com/spreadsheets/d/1Jl9fN1wNGhqj5SkljHGKHVYtNJAVK36e/edit?usp=share_link&ouid=100450587141122348038&rtpof=true&sd=true
@Aragorn450
Жыл бұрын
@@ModestMaker Thanks for the spreadsheet, although, it's a link that requests access, so you may get a few emails asking for access to the document... Like from me! 😄
@RonnieTheSim
Жыл бұрын
@@ModestMaker It's just lovely. thank you!
@ModestMaker
Жыл бұрын
@@Aragorn450 Thanks Charlie - fixed!
@ModestMaker
Жыл бұрын
@@RonnieTheSim Appreciate that - thank you!
@KammutierSpule
Ай бұрын
Thanks for the detailed investigation! I noticed you placed the sensor in the middle of the tube, while the holes are in the side, so they get dry faster than the central core. Actually, when you took out the probe, it was still wet.. which could interfere with the reading value. May improve the experiment with other configuration? eg: no lateral holes but allow evaporation from the top only? Since the tube is small, it may be evaporating faster on the sides and it receive more sun
@ModestMaker
Ай бұрын
Thank You. Yes- I understand the potential for error but based on other experiments, the challenges are similar in field conditions independent of being in a column. I am not clear as to the reason- it perhaps may have something to do with soil compacting after wetting. I just find they are not reliable at least for my tested soil type. See 10:40 for field installation.
@sebakiller9736
Жыл бұрын
Nice Video and a lot of informations. Thanks for your work
@ModestMaker
Жыл бұрын
Glad you liked it!
@ConstantinosFrantzis
Жыл бұрын
Great video! I've got a couple of these sensors myself (for irrigation monitoring for my home garden) and this is good to know but unfortunate. I'm wondering if there's an issue of adhesion and compressed soil. 1) Water sticks onto the coating of the sensors, so it may be that if there's any water present, it'll be on the 2) Clayey/silty soils are pretty compressible. Inserting the sensor into soil will create a dense region around the sensor which may reduce water permeability away from the sensor itself.
@ModestMaker
Жыл бұрын
Possibly. This is why I qualified my conclusions for “silty clay soils”, although I have witnessed the same behavior in premium potting soil (no measurements taken though). Thanks for those observations and suggestions 👍.
@addamsapple4925
2 ай бұрын
how did you get the values and how you measure soil weight and dry soil volume? please
@ModestMaker
Ай бұрын
I weighed everything with a scale. There’s a link to a spreadsheet with calculations in the description of the video.
@theirrigationguy700
8 ай бұрын
Interesting experiment. Was the soil loose or compacted?
@ModestMaker
8 ай бұрын
The soil was initially broken up but settled when I saturated the columns. The full playlist with subsequent experiments is here : kzitem.info/door/PLqJ5k4cakypy1E4J_tvEiD0kpFK1tGY3D&si=CV6QYCToKY1i2yJY
@J0stik
Жыл бұрын
trying to use capacitive soil moisture sensors for irrigation of tomato plants on my balcony. Re soldered timer chips for TLC 555 (because NE 555 chips). using Arduino NANO 33 IoT with set // Set ADC to use 12 bits, analogReadResolution(12);, that is giving me resolution from DryValue1 = 3480; to about WetValue1 = 1910; (dry soil to almost dripping wet saturation). i probably need to look more at soil type (bulk density), field density, irrigation point and Willting Point. overal great video, I have to learn a bit more. It is not as easy as to set "two point calibration" and hope for the best :( :D
@ModestMaker
Жыл бұрын
I agree on the two point calibration challenge. My concern is the sensor response is non linear as evidenced by relative insensitivity to water loss. I don’t think increasing resolution will help since (at least for my soil type) the signal itself is insensitive, but please share if you come up with any interesting results or further mods. Thanks for sharing!
@J0stik
Жыл бұрын
@@ModestMaker yop, i have resolution from about 1000 (fully saturated soil) to 3550 (air), using simple kalman filter to at least somehow smoother spikes, mapped and constrained values to percentage (0 to 100 percent). but i will need to do full calibration for each sensor (for "medium" that i am using) determining field capacity and wilting point for coco coir + perlite. oh why have i gone through this rabbit hole ? :(
@ModestMaker
Жыл бұрын
I know- right? I am working on a radiation shield for temp but as soon as I think I have it figured out, something else creeps up 🙄. The reward will be to finally get it all right but it’s a long and winding road though.
@J0stik
Жыл бұрын
@@ModestMaker yop, i have set up second monitor for one particular plant. Two sensors in one pot (15cm apart) protected from water (resoldered timinig chip, glue heat shrink on electronic part pcb and epoxy on sides of pcb not to soak moisture from sides) just to determine wilting point by observation (to look at plant with eyes, when it will start to suffer from not enough of water) roots are in fairly constant temperature (20-21 °C) plant have not been watered for about 4 days and moisture percentage is slowly but steadily raising on one sensor (dont know why) plant is still pretty much thriving ...
@ModestMaker
Жыл бұрын
@@J0stikEyes are the best!
@mr.blacktown197
3 ай бұрын
is it possible that your sensor in this setup have a faulty reading because of the bad sensor? I have come across this video: kzitem.info/news/bejne/qn2GmWyYs198Z20si=Af19SZJ_XlXwAuC0 , Did your sensor use ne555, doesn't have voltage regulator or missing output resistor?
@ModestMaker
3 ай бұрын
I checked all that here: kzitem.info/news/bejne/zZhqrpiZqYuIdoYsi=_xzaAGwenIYx4eBV . All sensors went through thorough quality control before selection.
@iddddd900
6 ай бұрын
coding ?
@ModestMaker
6 ай бұрын
Buying, Programming, and Testing Capacitance Soil Moisture Sensors kzitem.info/news/bejne/zZhqrpiZqYuIdoY
@Lisas4us
Жыл бұрын
Exactly, all this hobby soil moisture sensors are crap. We tried a lot of them. The capacitive once are just so bad. Soil type is a factor, but changing the sensor a bit, a mouse or worm will give you different readings.
@ModestMaker
Жыл бұрын
Yes- in addition, two of the three I have installed in my formal setup just started reporting weird data after 6 weeks installed in the field. Temperature shows some promise- I will post some new results shortly, suffice it to say I haven’t had much luck with capacitance.
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