code: function raspi_i2c_devname()
  {
      try {
          var revisionBuffer = fs.readFileSync('/sys/module/bcm2708/parameters/boardrev');
          var revisionInt = parseInt(revisionBuffer.toString(), 10);
          //console.log('Raspberry Pi board revision: ', revisionInt);
          // Older boards use i2c-0, newer boards use i2c-1
          if ((revisionInt === 2) || (revisionInt === 3)) {
              return '/dev/i2c-0';
          }
          else {
              return '/dev/i2c-1';
          }
      }
      catch(e) {
          if (e.code === 'ENOENT') {
              //console.log('Not a Raspberry Pi');
              return '';
          }
          else {
              throw e;
          }
      }
  }
docs: If the system is a Raspberry Pi return the correct i2c device name. Else return empty string.