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Capacitive soil moisture sensor value 4095

Posted: Sun Dec 13, 2020 6:19 pm
by Aornn13
Hi guys !
I have bought a capacitive soil moisture sensor and when I try to check the values here is what i got :

Code: Select all

Moisture Sensor Value:3831
Moisture Sensor Value:3953
Moisture Sensor Value:4007
Moisture Sensor Value:4041
Moisture Sensor Value:4059
Moisture Sensor Value:4078
Moisture Sensor Value:4093
Is it correct value ?? because when i put it inside a glass full of water, the value goes around 2550... And on all the tutorial they have values around 700
my connections are :
VCC -> 3.3 V
Gnd -> GND
DATA -> PIN G4

Here is the pin configuration of my board https://randomnerdtutorials.com/esp32-a ... duino-ide/

So are those values correct ??

Thanks for all !

Re: Capacitive soil moisture sensor value 4095

Posted: Mon Dec 14, 2020 1:08 am
by ESP_Sprite
Hard to say. Which moisture sensor do you have? Do you have a logic analyzer or scope to double-check the result?

Re: Capacitive soil moisture sensor value 4095

Posted: Mon Dec 14, 2020 10:02 am
by Aornn13
Hi !
This is my captor :) https://www.ebay.fr/itm/Analog-Capaciti ... 2321853501

This morning I have decided to check value (the voltage send to my esp) with my multimeter and display this voltage on the serial printer of my esp. To get value i pluf it between gnd and data.
So when my multimeter is plug both of them display 2.7V but when I unplug the multimeter, the value on the esp increase to 3V for no reason, it still in the same environment. When I plug back the multimeter they both go and stay at 2.7 V

Re: Capacitive soil moisture sensor value 4095

Posted: Mon Dec 14, 2020 10:51 am
by MerlynMetal
The ESP8266 has a 10 bit ADC which displays values from 0 to 1023. Values around 700 apply to the 10 bit ADC.
The ESP32 has a 12 bit ADC which will display values from 0 to 4095 so you'll have to calibrate your capacitive sensor in the 0-4095 range.

Re: Capacitive soil moisture sensor value 4095

Posted: Mon Dec 14, 2020 12:54 pm
by ESP_Sprite
I get " Le vendeur a terminé cette vente, car l'objet n'est plus disponible.", so no description there...

Could it be that that thing needs a pullup or pulldown?

Re: Capacitive soil moisture sensor value 4095

Posted: Mon Dec 14, 2020 1:16 pm
by Aornn13
I don't need any of resistor.
If you prefere here is the schema of my sensors :
Image