​

#include <Wire.h>

void setup()

{

  Wire.begin();

  Serial.begin(9600);

  while (!Serial);             // Leonardo: wait for serial monitor

  Serial.println("\nI2C Scanner");

}

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

}