/**
 * I2C scanner
 * 
 */
 
#include <Wire.h> //include Wire.h library

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

  Wire.begin(); // Wire communication begin
  //Serial.begin(9600); // The baudrate of Serial monitor is set in 9600
  //while (!Serial); // Waiting for Serial Monitor
  //Serial.println("\nI2C Scanner\n\n");
}

void loop()
{
  byte error, address; //variable for error and I2C address
  int nDevices;

  Serial.println("\n\n\nScanning...");

  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)
    {
        digitalWrite(0, HIGH);
        delay(2000);
        digitalWrite(0, LOW);
        delay(2000);
      Serial.print("I2C device found at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.print(address, HEX);
      Serial.println("  !");
      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");
    for (int i=0; i<10; i++) {
        digitalWrite(0, HIGH);
        delay(200);
        digitalWrite(0, LOW);
        delay(200);
    }
  }
  else
  {
    Serial.print("...done. Found ");
    Serial.print(nDevices);
    Serial.println( nDevices == 1 ? " device." : " devices.");
  }

  delay(5000); // wait 5 seconds for the next I2C scan
}