Smart Agriculture for Cats

[neilhao]

I often forgot to water the barley grass for my cats. Thus, I spent two days for designing a “Smart Agriculture” project for my cats, one day for hardware design, another day for the software design.
The hardware is based on ESP32. The software is based on IBM Node-Red and Mosquitto, totally using private cloud.

Features:
    7-Day Programmable Scheduling
    Up to two soil moisture sensors support
    Up to two relays support
    Up to two controlled 5V outputs
    ADC, I2C, SPI and additional IOs extension connectors
    USB Type C Socket

Project Wiki: https://uniteng.com/wiki/doku.php?id=esp32:smartagriculture

[Doctorandus_P]

Looks like a fun project, but from what I know of those moisture sensors, they don't last very long.
A loadcell that measures the weight is probably a better option, or even just a float switch.

[paleogizmo]

Assuming your are talking about the two-probe style of sensor, I think that this can be mitigated by using an h-bridge to apply ac voltage. One trick if you decide to use a load cell instead - the absolute weight doesn't matter, you are only checking for when the soil is saturated, meaning that the relative change in weight per unit time has become flat (or sufficiently low).

[AndreKR]

The capacitive ones are alright.

How do you dispense the water though?

[rpiloverbd]

Interesting project. Thanks a lot for sharing.

[cdev]

I've been thinking about a bird bath that cleans itself and refills itself automatically.

Hopefully crows which are very smart. Will use it.

Cats on the other hand, mostly try very hard to look smart.  Maybe the bird bath will successfully recognize them doing this and irrigate them.

[cdev]

@neilhao,  (looking at your web site) You would like a patch antenna that I made some time ago. It was a diversity antenna that allowed both vertical and horizontal polarization simultaneously. It worked great. It had symmetry around  45 degree angle. I think I remember enough to make it, you could probably figure out how to make it.

It had a flat reflector and was slightly larger than a DVD. Its reflector was circular.

[rooppoorali]

Have you designed any casing for the hardware?

[libralect]

Oddly enough, the soil needs water as much as the sun shines, so if you have a solar panel measured to the water needs, it recharges the batteries just enough for the amount required every day, and starts watering at night based on a sensor that measures dusk on the solar charge controller. Not idea, however it's a solar based budget idea which can be useful to some folk.