Soil Moisture Sensor
En soil moisture sensor är en sensor som mäter av fuktigheten i jord och andra liknande material. De två pinnarna på sensorn undersöker jorden och mäter av hur fuktig den är. Ju mer vatten det är i jorden desto bättre leder pinnarna ström och det blir en mindre resistans. Ju mindre vatten i jorden desto sämre leder pinnarna ström och resistansen blir större.
Här är ett exempel på kod man kan använda för att få sensorn att fungera:
/* Soil Mositure Basic Example
This sketch was written by SparkFun Electronics
Joel Bartlett
August 31, 2015
Basic skecth to print out soil moisture values to the Serial Monitor Released under the MIT License(http://opensource.org/licenses/MIT)
*/
int val = 0; //value for storing moisture value
int soilPin = A0;//Declare a variable for the soil moisture sensor
int soilPower = 7;//Variable for Soil moisture Power
//Rather than powering the sensor through the 3.3V or 5V pins,
//we’ll use a digital pin to power the sensor. This will
//prevent corrosion of the sensor as it sits in the soil.
void setup()
{
Serial.begin(9600); // open serial over USB
pinMode(soilPower, OUTPUT);//Set D7 as an OUTPUT
digitalWrite(soilPower, LOW);//Set to LOW so no power is flowing through the sensor
}
void loop()
{
Serial.print(“Soil Moisture = “);
//get soil moisture value from the function below and print it
Serial.println(readSoil());
//This 1 second timefrme is used so you can test the sensor and see it change in real-time.
//For in-plant applications, you will want to take readings much less frequently.
delay(1000);//take a reading every second
}
//This is a function used to get the soil moisture content
int readSoil()
{
digitalWrite(soilPower, HIGH);//turn D7 “On” delay(10);//wait 10 milliseconds val = analogRead(soilPin);//Read the SIG value form sensor digitalWrite(soilPower, LOW);//turn D7 “Off” return val;//send current moisture value
}