It would be interesting and very useful (it could even have other applications not only for automatic irrigation) to be able to manage automatic irrigation systems using the various current SONOFF devices; to have an ultrasonic water level meter, integrated into the eWeLink App, to place it on top of the water tank and be able to know or measure the filling volume of the tank.
Greetings.
Adolf Rupérez
To check whether the water level reaches a specific point, I simply use a float sensor attached to the cable connector and a Sonoff 05P sensor.
Of course, this only gives a zero-one indication per point and not a 1L, 5L, 10L scale of how much the tank is filling up.
When the water level in the tank is very low, I use a float switch inside the tank to prevent the submersible pump (which operates on 230V AC) from activating.
The float switch disconnects a SONOFF MINIR4 device, which powers the submersible pump. This prevents the pump from running without a load.
The MINIR4 device contains the irrigation schedule. This irrigation schedule includes some sophisticated scenes with other SONOFF devices, which I manage from the eWeLink app and my i-Host: a humidity and temperature sensor and a light sensor.
Both of these deactivate irrigation if the humidity is above a set level (75%) or if it is raining.
However, filling the tank requires a device that measures or manages the water that needs to be replenished and also controls the tank’s filling valve.
And the i-Host’s voice prompts provide updates on what is happening.
I have a similar solution. It monitors low water levels in the tank to shut off the water pump so it doesn’t run dry.
My second solution is based on two 05P units. One monitors low water levels to protect the pump, and the other monitors high water levels to prevent the tank from overflowing.
There are probably solutions on the market that measure water levels across the entire height of the tank, but nothing comes to mind right now, and they probably won’t be compatible with Sonoff/EweLink.
https://forum.ewelink.cc/t/sonoffs-alternative-to-autoaqua-smart-level-security/
Theoretically, the SONOFF Zigbee Smart Water Valve is supposed to have the ability to monitor how much water has flowed, but I don’t have it, so it’s hard for me to say.
I actually have this same need. The float option (and other devices that depend upon floating bits) does not work because a layer of ice sometimes forms on the top of the cistern, trapping the float whilst the water level continues to drop.
I suppose that SNZB-05P devices placed on the wall of the cistern at different levels could give me some feedback, but getting in there to retrieve, recharge and replace them, periodically, would be a major drawback.
There are a lot of different sensors on the market, both ultrasonic and laser, but these are just modules from which you have to build the device yourself and then figure out how to make it work with eWeLink.
A ready-made solution compatible with eWeLink is a challenge.
Theoretically, you could experiment with
As for the 05P, it’s a solution, but… it’s a bit expensive. As for replacements, the battery is supposed to last up to 5 years, although since the tank is in such low temperatures, the battery life will be shorter.
There’s also the issue of the ZigBee signal, since it’s a metal tank.
If you don’t need to monitor the current water level and just want to know when the water is reaching a certain point, a single 05P will suffice, provided you can permanently install the cable into the tank.
In this case, you would use heat shrinkable insulation with adhesive on the entire cable, leaving only the end with the USB connector (which will touch the water) uncovered. This way, you still have the same functionality of the 05P, but without the need to insert it into the tank, and just attach the cable once.
You would probably want something like… but this is a solution for building the device yourself.
Alternatively, if you have a freezing of the moving element, then maybe…
