Capacitive Soil Moisture Sensor v1.2 - Always zero value

Hello,

I bought three of these modules (pictures in the attachment), but I don't seem to get any values.

At first i connected one of the sensors to my Arduino Uno (GND to GND, VCC to 3.3 V and AUOT to A0). As shown in many videos and on the Internet. It's just the three cables with no other components.

I use Arduino IDE (1.8.12) with my desktop computer.

The code is also simply, just Serial.beginn(9600) in Setup an Serial.println(analogRead(A0)) in loop should work.

I always get 0 as values. These values shouldn't appear at all. I testet also 5V and another Arduino Uno, same result. Glass of water, wet earth all have no influence :-\ I also exchanged the connection cables, tested all three sensors. I also tested two NodeMCU ESP8266. Here I don't get 0, but always small values like 7.

I don't understand where the error is and what else I can try. The modules were very cheap, but I don't think they are faulty. On the other hand, I don't belive my Arduinos Unos have a problem.

greetings

derwiderstand:
The modules were very cheap, but I don't think they are faulty.

Why not, you have a lot of evidence to suggest that they may be.
Try powering the sensors with 5V and using a digital volt meter to measure the output. If still no go, then contact the vendor for support.

I also had this problem. But when i power the sensor with 5V i get an output.
Thanks for the help.

Thx for your answer.

I would be surprised if all three should be broken :-\ Furthermore after hours of testing, there are a few things that I don't quite understand with the analog input. I cannot completely rule out that the problem is on my side

The whole magic whith analog input is: the voltage is measured and"translated" to a value? No more no less?

1.) If i run the code without ANY cables or modules attached to the arduino uno, the analog output of A0 is relativ stable at 400 +-30. I don't quite understand why there is such hight output at all.

2.) Sometimes when i attach only a cable at the a0-pin, the output changes. Sometimes it goes up and down up and down up and down. I dont know why this happens. Is that normal?

1032
900
845
762
...
252
105
15
0
0
17
167
..
856
980

I also testet a rain drop sensor from the same seller. In contrast to the humidity sensors the rain drop sensors seems to work fine with the analog input.

Greetings

derwiderstand:
1.) If i run the code without ANY cables or modules attached to the arduino uno, the analog output of A0 is relativ stable at 400 +-30. I don't quite understand why there is such hight output at all.

2.) Sometimes when i attach only a cable at the a0-pin, the output changes. Sometimes it goes up and down up and down up and down. I dont know why this happens. Is that normal?

When you have a floating input q.v. as you do in both these cases, all bets are off as to what value you will get.