Hi! I’m super excited about building my smart irrigation system using your tools. I’m mostly familiar with using soil potential data for assessing water availability and I wonder if your setup can work with something like the Watermark sensor (https://www.irrometer.com/200ss.html).
My experience with collecting environmental data has always been on the Campbell Scientific platform and in large agricultural settings using sensors like this: https://www.campbellsci.com/253-l or
https://www.metergroup.com/environment/products/teros-21/
I really think your set of tools and code could make that a lot easier to handle if you want to add the ability to work with watermark sensors. The digital sensor from Metergroup provides output in SDI-12 format and I think there are several ways to read the digital data but the digital sensors are quite expensive at almost $200 each. The Watermark ones can be found on eBay for $50. $50 sure sounds more economical!
Anyway, I’m super interested in building something that uses this type of sensor or a coupled set of these sensors with volumetric water content sensors to tell me when to irrigate but I don’t think the capacity is built in to your platform right now. Do you have an interest in trying to make that work? Preferably with the cheaper Watermark sensor?
One of the reasons why having potential data is useful is in building water retention curves (https://en.wikipedia.org/wiki/Water_retention_curve) so we know how much water the plants can access via capillary forces compared to how much is physically in the soil matrix as a volumetric potential. Most of the sensors out there just give volumetric water content, not potential.
Thank you!
Hi there! Reading the Watermark sensor is no easy task indeed. Took us a while to get accurate and reliable data out of these sensors.
Great start indeed is the official documentation provided by Irrometer: https://www.irrometer.com/200ss.html Especially the pseudo-AC excitation is very important and make sure you calibrate the readings using the soil temperature.
There's quite some off-the-shelf hardware on the market already. Look for a device that has a low power consumption so you can measure throughout the year, for example: https://www.crodeon.com/blogs/news/connecting-a-watermark-sensor-to-the-cloud
Let me know if you have any more questions!
Hello,
I was referring to the analog sensor, for the sensors with the SDI-12, it looks not so complicate.
After thinking a little bit to the integration of those sensors, I think that the simplest way to connect the sensors to the Hydrosys4 is to use the Arduino and the HC-12 radio transmitter. I already implemented the integration of my soil moisture sensors using the HC-12 transmitter (with distances around 1 km) so the integration will just be a matter of connecting the Sensors to the Arduino, part of the Arduino code is already written.
Below a link to the article where I describe the procedure.
In this way multiple probes can be connected to one System at distance.
Do you mean the SDI-12 sensors like TEROS-21 or analog sensors like the Watermark? Here is a bit more information on the SDI-12 interface and ways to use SDI-12 based soil moisture sensors on Raspberry Pi.
The reason I'm interested in doing this is that as part of my PhD research I'm currently building a large multi-basin, county wide monitoring network of soil moisture sensors built on the Campbell Scientific platform. Each data logger is nearly $1,000. I'm interested in bridging the gap between commercial advanced irrigation systems and hobby systems but right now sensors are a problem. We still depend on high-end commercial sensors from companies like Watermark, MeterGroup, and Campbell Scientific for below-ground measurements. The data logging itself could possibly be done on much cheaper hardware.
If you could suggest a way to connect one of these to your system as a sensor input that would be great! Notice that this person already tested some of the SDI-12 sensors I've discussed but their solution doesn't have the ability to control irrigation like yours. They just log:
https://liudr.wordpress.com/gadget/sdi-12-usb-adapter/
Hi,
I had a look at the sensor, it was an interesting reading.
The interface with this sensor can be developed but is definitely not simple.
Not in my plan right now.