code: function getLux(volMeasured) {
    var lux;
  
    lux = parseInt(volMeasured, 10);
  
    lux = 2.3 * lux - 3200;
    lux = lux >= 0 ? lux : 0;
  
    return lux;
  }
docs: TODO: calculate lux from the measured analog input(0 ~ 1800 in the case of Beaglebone black analog input)