Watermark arduino 3.3 headache

  • Hi all,

    I'm programming a watermark sensor and an arduino 3.3v. I tried a lot of sketches and connections and did not work.

    Anybody used this sensor? does anybody has docs or sketch or pictures connecting...?

    I'm desperate!!!



  • Hero Member

    @ecabanas Reading from what is published on the watermark sensors it is "resistance" based. E.g. a couple of electrodes in a nice housing and corrosion resistant. Standard method of reading these sensors is determine resistance (Ohms law) by applying a (AC = reversing polarity) current and measuring the voltage over the sensor. Most of the moisture sketches are written this way. You need to know the "resistance / moisture curve" of the sensor.

    Can you show us what have and tried?

  • @AWI said in Watermark arduino 3.3 headache:

    how us

    Hi @AWI

    I tryied this hardware as a watermark: WATERMARK 200SS from http://www.irrometer.com/sensors.html

    My logger is a Sodag One based on arduino:

    I followed this schema to wire it because the One is working at 3.3V


    and this sketch

    I don't know if you need more info about it.



    //Tabular Serial Printing  of Leaf Sensor Signal Data - AgrHouse.com
    const int LeafSensor1=0;  //Leaf Sensor on Analog Pin 0
    void setup()
      Serial.begin(9600); //Start Serial Port with Baud = 9600
    void loop()
      Serial.println("Leaf Sensor Arduino Data Logger");  // AgriHouse.com 
      Serial.println("\nAnalog Pin #\tRaw Value\tPercent");
      for (int i = 0; i < 10; i++)
        int val = analogRead(LeafSensor1);           //Read Leaf Sensor Pin A0
        int per = map(val, 0, 1023, 0, 100); //Convert to Percentage
        Serial.print(per);           //Print Percentage Analog Value
        Serial.println("%");         //Print % Sign and Newline
        delay(1000);                 //Wait 1 second, then repeat

  • Hero Member

    @ecabanas Your sketch and circuit look fine to me. I don't know the Sodaq One, but should the line
    const int LeafSensor1=0; //Leaf Sensor on Analog Pin 0 not refer to pin "A0"...
    const int LeafSensor1=A0; //Leaf Sensor on Analog Pin 0 ?

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