Arduino I2C Scanner     This article Is trick  about  serial connection on  I2C-Bus  in Arduino Board.  Because of the time on develop software associated  I2C device, the device may not respond. So i t can not be said that the problem is that the i2c device or develop a program.     Advantages of I2C Scanner     Find the Address of I2C Device.  Check responds of I2C device.    * If found I2C Device Address, It can used to program the Arduino board.   * If not found  I2C Device Address,  Check the jumper cable (if  jumper cable are  Correct  Device may be  cracked .)     Example Program    Examples Circuit use Real Time Clock (DS1307) and 16x2 LCD I2C       i2c scanner Program   Referent       - https://playground.arduino.cc/Main/I2cScanner