i’m a software developer and no gardener, yet i like healthy plants.
For that i am looking for some cheap / inexpensive sensors that i can put in my plants to remind me to water them.
My problem is that most sensors work with bluetooth, but i have plants all over my house, mainly in my office in the attic. Home Assistant on Raspberry PI is located in the basement.
WiFi is available everywhere, because i use a Mesh Network / WiFi Repeaters.
I don’t know anything about MQTT, ESPHome, etc.
My current setup for Automation is mainly Philips Hue and Homematic / Homematic IP.
Is there anything you could recommend hardware & setup wise?
HA have the option now to use BT proxies to extend BT coverage.
I have personally chosen to go with this: April soil moisture sensor – April Brother CO.,LTD
It is ESP based and I made my own program for ESP-Now, but it should be extremely easy to set it up with ESPHome and get it on WiFi 2.4Ghz.
so, as i said i don’t know anything about ESPHome: How would i be able to connect them to home assistant?
I will put them in the plants in my attic, then connect somehow via wifi and then i can add them to Home Assistant or do i have to buy other hardware as well?
I was also looking into Mi Flora related sensors like these:
Would it make sense to connect them to Home Assistant and if so, how would i overcome the limited BT Range that would make it impossible to communicate directly to Home Assistant?
Well, ESPHome is actually extremely easy to handle. The developers of ESPHome have made DIY IoT devices a piece of cake and there is a huge forum here to help you.
I suggest you buy maybe a nodeMCU with an ESP32 chip and then a IoT starter kit and then you play around. Youtube is a friend here and there are countless sites dedicated to this also.
Once you got that then a whole new world of possibilities open up to you.
Just be careful! You might be hit with the DIY fever and with suddenly endless possibilities comes suddenly endless projects that will suck away all your spare time.
Here is an example for a IoT starter kit. There are other variations with more or less or different parts included.
Those Xiaomi use the two prongs to measure resistance between them, effectively (wet soil conducts better than dry soil). the downside is that the two prongs are basically exposed metal, and will corrode fairly quickly and that in turn will make these things progressively less reliable.
(Full disclosure here: I am in the same boat as you, I just happened to have dug into these moisture thingies a bit, which is where I learned about that bit…)
True, the resistive sensors will erode and that will also cause a pollution of the soil.
The sensor I linked to is a capacitive sensor which has no direct contact with the soil.
The pro of the capactive sensor is no corrosion, no pollution and a much slower degrading device.
The cons is that you can not measure nutritions in the soil, but in my experience those values are pretty bogus also, because the nutritions are relative to the moisture and not in a direct way, so it is pretty unpredictable.