Soil Moisture Sensor AliExpress

ESPHome
1

Hi to all!
After suggestion of another member I opened a new topic for this.

I am trying different sensors, modules etc with my home assistant to see what it (I) can do.

I tried the next sensor for soil moisture:

https://a.aliexpress.com/_ExqUPDK

Powered through 3.3v, gnd and had sensor has DO and AO. Tried both outputs but still same (no) output when I dip sensor in cup of water and out of water. I checked outputs through multimeter but no mAmps or Volts.

Do I need something different to use this type of sensors?

2

If you immerse the sensor in water or you keep it out, does the S LED change state? If not try to adjust the potentiometer.

1 Like
3

Yeap, the led lights!

My question is: I should be able to see change in mA or Volts respectively. No need of any other board. Correct?

4

No, you should see difference in DC voltage between -pin and D-pin

1 Like
5

Will try again soon and revert with results. Will also try 5v in even if manufacturer states that can work from 3.3v.

6

So, here are the “news”:

Sensor is “working”. I get 3.2v when out of (cup of) water and 0.50v when dipped in water.

Perfect. BUT:

When I connect the sensor to my AI of my Esp board (KinCony 868-AIO), then I can’t get any input. And I mean NO INPUT. No change in Volts AT ALL.

My troubleshooting:

  1. I tried a voltage/current generator (https://a.aliexpress.com/_EwgS75o) with external power source and I get voltage measurement on my board (868-AIO), so board is working. Also tried DI and works but that doesn’t matter.

  2. I rechecked my soil sensor output with multimeter (when NOT connected with 868-AIO) and sensor output still works.

  3. I tried to take sensor’s GND both from main GND of board and AI GND. Same result. No input from sensor into board.

  4. I connected the DO of sensor to board and board reacts (change in voltage) to signal. Only of course 2 voltages not an analog out.

  5. I messed around with the potentiometer, still nothing.

  6. I tried external power source to 4volts still the same. No input in any channel I try in the board, normal input on multimeter. Inputs of board working.

My only idea is if I can “multiply” reading of input but does not make any sense.

Any ideas?

7

Is there a reason to use board like that to read soil moisture?
Try with TP1 or TP2 pins.

8

I bought this board to experiment and what I am trying to do is a “simulation” of a smart home.

So I can see if it has the potential to manage a whole home and trial/error various aspects.

I use TP1 for sht30 temp/humidity sensors. Manufacturer claims that can use many sensors at the same time (another experiment on my list).

On TP2 I currently have a DS18B20 temp sensor from a previous test (no need to leave it there).

What the manufacturer claims is that “The sensor’s load-bearing capacity is weak”. Cannot see how this is relevant.

Tried to multiply sensor input in my yaml but still no result.

9

Good luck with that. I wouldn’t even give a try.

STH30 sensors use normally I2C.