Moisture sensors bad value

Products & Technology Grove
#1

Hello, i have installed
Grove base kit with raspbery on pi4b form this tutorial:


i have this sensor : https://wiki.seeedstudio.com/Grove-Moisture_Sensor/
I have a problem with numerical values :frowning:
In tutorial are these values: 0-300 300-600 600- or higher.
If I put the moisture to moist soil, it comes > 1800
how can i fix it please?
Thanks
#2

Hi @dxtx:
can you give me the connection of hardware? and only sign area can be used as below pic.
image

#3

Hi,
i h ave all componnets from Grove base kit with raspbery pi 4b:

l2c - first port - LCD display
D5 - DHT11
D16 - grove relay
A0 - grove Moisture sensor

Python defined:

def main():
lcd = JHD1802()
teplota = DHT(‘11’, 5)
spinac = GroveRelay(16)
puda = GroveMoistureSensor(0)

I checked the soil sensor connection and pulled it up - problem is same - the sensor shows very high values.

Screenshot_53
Screenshot_53750×271 18.3 KB

#4

Hi @dxtx:
Can you give me the data that disconnect the soil sensor? like this.

image
image1440×1080 214 KB

and we can get as below data.
image

#5

I don’t understand your request.
Here is foto rapsberry how i have connected it.

IMG_5846
IMG_58463024×4032 1.97 MB

Here is program output from sensor:
Screenshot_47

#6

Hi @dxtx :
It is a good choice to only the humidity sensor is left on the basehat and the others are unplugged then run test.py.

#7

this was, of course, the first option I tried. Unfortunately, the result is the same. The sensor shows very high values ​​in any A port. How can this be fixed, please?

IMG_5858
IMG_58583024×4032 2.07 MB
Screenshot_48

#8

HI @dxtx:
did you use this code

#9

same problem :frowning:
Screenshot_49

#10

Hi @dxtx:
1.Can you disconnect all elements and only connect to baseHat.like this.
image
2. and run the adc.py code.
I would say, I want to know the Basehat is whether damage.

#11

Here is output with disconnect all elements:Screenshot_50

#12

Hi @dxtx:
I would say, the base-hat is normal to work. because I got the same data from my basehat.
image
So the wiki needs to update. thanks for your feedback.

#13

OK, thank you,
can you please write what are the new values ​​for the definition soil moisture -
In wiki is now - 0-300 dry; 301, 600 moist; > 600 wet

dry - 0 - ?
moist - ? - ?
wet - > ?

Thank you

#14

Hi, i have exactly the same problem with the Capacitive Moisture Sensor (Corrosion-Resistant) attached to the Grove Base Hat for Raspberry Pi, did you ever fixed the problem?

#15

Issue still exists :frowning:

image
Code source: Wiki

Measurements in wet soil (whole sensor part is under soil)

Can someone help me with this?

@Hansen

#16

The problem is the NE555 timing chip requires a minimum voltage greater than 3.3. (4.8) i believe. Thus the values will always be off. These capacitive sensors are garbage. 85% of them on the market are like this.

#17

I have tested today and the Capacitive Moisture Sensor (Corrosion-Resistant) is working as expected

企业微信截图_1704439516360
企业微信截图_1704439516360906×687 104 KB

#18

Hello all - I am using the basic moisture sensor for my student project at Uni and I’m getting the same really high values. I have no idea how to fix this.
@Seeed_Seraphina you managed to get it working. How do I get it working?

I have a RPi 3b+ and the grove hat for RasberryPi

#19

I use grove_moisture_sensor.py from grove.pi library. This code works fine. Which demo are you using?

#20

The same one. Downloaded from the gove studio git repository.
But is ok I have found a work around,
Just rewrote the whole ADC class with actual calculations based on the input value and verified with a voltmeter…
Very poor implementation of the product, this has cost me hours in developement.