ChangeSensorI2CAddress.ino

#include <I2CSoilMoistureSensor.h>
#include <Wire.h>

I2CSoilMoistureSensor sensor(0x20);

void setup() {
  Wire.begin();
  Serial.begin(9600);

  sensor.begin(); // reset sensor
  delay(1000); // give some time to boot up
  Serial.print("I2C Soil Moisture Sensor Address: ");
  Serial.println(sensor.getAddress(),HEX);
  Serial.print("Sensor Firmware version: ");
  Serial.println(sensor.getVersion(),HEX);
  Serial.println();

  Serial.print("Change address to 0x21 ...");
  if (sensor.setAddress(0x21,true)) // set Sensor Address to 0x21 and reset
    Serial.println("... DONE");
  else
    Serial.println("... ERROR");
  Serial.println();
}

/*loop scans I2C bus and displays foud addresses*/
void loop() {
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ ) {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0) {
      Serial.print("I2C device found at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4) {
      Serial.print("Unknown error at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.println(address,HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);           // wait 5 seconds for next scan
}