Wireless Moisture Monitor (ESP8266 + Moisture Sensor)

Introduction: Wireless Moisture Monitor (ESP8266 + Moisture Sensor)

I buy parsley in pot, and most of day, soil were dry. So I decide to make this project, about sensing moisture of soil in pot with parsley, to check, when I need pour soil with water.

I think, this sensor (Capacitive moisture sensor v1.2) is good because:

1. has waterproof electrodes, so you don't worry about corrosion.

2. is cheap -> 1,5 - 2 $

Step 1: BOM

Bill of materials (affiliate links, if you want buy this materials, you can support me, if you buy through this links):

1. Capacitive moisture sensor v1.2.

Link:capacitive moisture sensor v1.2

2. Wemos D1 Mini.

Link: Wemos D1 Mini

3. ADS1115 for measure analog values from sensor.

Link: ADS1115

4. Battery - I use 18650, lithium - ion battery.

Link:Battery 18650

(In past , I bought trustfire mark. Good battery has own code to recognize original)

5. Battery holder (you can cut out one side, for better put in battery to holder)

Link: Battery holder

6. Cables . I use AWG 22 type.

Link:Cables

7. Case.

Link: Case

Of course, you need soil for measure :D

Step 2: Circuit

I do classic circuit. Firstly, I power Wemos with 4,2 volts from lithium battery. It is possible, and I connect it to 5V pin. It works, without neccesary of regulator!

Deep sleep current is under 0,3 mA.

For powering sensor and ADC, I use pin 8 from wemos. Very important is using constant voltage (3,3 V) and do not use battery (where voltage change from 3 volts to 4,2 volts)

Step 3: Code

I use ThinkSpeak as store data. I use 10 minutes intervals.

Don't forget to connect Reset pin with D0 to restart wemos after sleeping. I created diagram to show how code work.

Code in Arduino:

Step 4: Final

If you will build circuit, please use longer cables. Not like me.

Step 5: Testing

For measure moisture, use cca 3/4 of sensor's surface. Be care, and don't pour sensor with water.

I use Thingspeak for saving values. I can say, that values depend on temperature, so monitoring of temperature should be good.

I started to measure 25. March dinner (I pour parsley) and then I wait. During night day, values not chaning.

In 26. March, values rise up as temperature rise up. But next night (from 26. March to 27. March), values were higher. So soil in pot were drier (more arid)

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    10 Discussions

    0
    MarceloF86
    MarceloF86

    Question 4 months ago

    Hello, I am interested in the connection to the D8 (Wemos), is the current (I think mA or less) sufficient to supply the ADS1115 and the humidity sensor?
    I am building something similar but with 2 humidity sensors and DTH22.
    Thank you very much, Marcelo.

    0
    Michal Choma
    Michal Choma

    Answer 4 months ago

    sorry, I dont know. But in general, sensors consumpt not much current, lets say 1 mA/sensor.

    0
    MarceloF86
    MarceloF86

    Reply 4 months ago

    Good!
    Thanks for you answer, last question, why do you connect ADDR Pin to V+ in ASD1115?

    0
    TonatiuhQ
    TonatiuhQ

    5 months ago

    Hello. Usually this sensor is working different in Arduino Uno or Mega, because the Voltage send a different data. For example, the same measure is 400 in arduino mega, and ESP8266 is near to 600. Do you have this? How did you calibrate the system?

    0
    Michal Choma
    Michal Choma

    Reply 5 months ago

    hello, I think, output from sensor depend also on input voltage, in my case it was 3.3 V. I dont calibrate system, it is pretty hard.

    0
    TonatiuhQ
    TonatiuhQ

    Reply 5 months ago

    I will measure it, and i will send my results.

    0
    pjaeil
    pjaeil

    1 year ago

    I get an error that wificonfig.h does not exist.
    Thank you for your link.

    0
    jamester90000
    jamester90000

    Question 1 year ago

    Hi, why do you need the ADS1115? I saw another guide where it goes straight from the sensor to the controller.

    0
    Michal Choma
    Michal Choma

    Answer 1 year ago

    I had problem with esp analog pin. It was not stable. Anyway, I think, the best method is measure input voltage (voltage between VCC and GND of sensor) and analog output (voltage between analog and GND) with INA219.