Shop
ConfiguratorGenerally
dynamic irrigation control
There are no clear specifications or guidelines on how to implement dynamic weather control.
In principle, the OpenSprinkler is just the tool, you have to work. That means trying things out until it works.
Up until now, the weather service and the “Zimmermann” or “Evapotranspiration” adaptation type were a good way to dynamically implement weather-dependent control.
Due to the incredible number of parameters such as water permeability of the soil, plant type and condition, sun intensity and shadows, pH value, nutrients, soil temperature, air humidity and much more, it is not possible to make definable specifications. This could only be done if one not only observed but also measured values.
Because one thing is missing from their configuration: a measuring instrument for the actual soil moisture. And that is exactly what is now possible with the new “Analog Sensor Board” and the soil moisture sensors from Truebner.
These measurements were created by my system, OpenSprinkler can create the graph directly.
In principle you proceed in two steps:
1. You continue to irrigate as usual, but measure the soil values, for example over a period of a few months
Here's an example, but it's about avenue trees: https://www.kassel.de/stätten/aurea/sensoren-am-auepark/sensor-bodenFeuchte-fuer-alleebaeume.php
2. You determine the optimal humidity range based on the measurement data, e.g. 15%-22% (this is just an example!)
You can then use these values to enter a linear program adjustment in OpenSprinkler
There is also the new “Program adjustments” function:
SMT50 soil moisture values briefly explained:
– 0% corresponds to completely dry soil
– 50% corresponds to the same amount of water as soil. The SMT50 is limited to 50%, only the SMT100 can measure up to 100%. However, a maximum of 60% occurs in nature, which is more like a swamp and is therefore irrelevant.
Setting explained:
– If soil moisture is 15% or less, we increase irrigation up to a factor of 1.5 (150%)
– If it is higher than 22%, we reduce it to a factor of 0.5 (50%).
– Between 15% and 22% the scale is linear, so at 18.5% it would be 100%
Combined with weather-dependent irrigation, this results in the optimal irrigation time for the desired soil moisture range.
If you observe this again over a period of time, you should be able to get an idea of whether the soil moisture can be kept constant or whether it still needs to be improved.
Hello from Portugal! I have been using OS for many years and just came across your(?) adaptation for soil moisture sensing. Exactly what was missing! However, I use LoRa moisture sensors at a depth of 30cm for our tree plantings. You already have Modbus up and running, how about http-GET or MQTT values?
Greetings, Gregor
Hi,
With the API you can read out all sensor values and log data via http-get. The documentation is in the Github repo.
Mqqt also outputs the sensor data.