function main(params, callback) {

    var INT16_t_MAX = 32767;

    var UINT16_t_MAX = 65536;

​

    var moduleTemp = (params.custom.moduleTemp / INT16_t_MAX * 120).toFixed(2);

    var dhtTemp = (params.custom.dhtTemp / INT16_t_MAX * 120).toFixed(2); // the DHT temp

    var dhtHum = (params.custom.dhtHum / UINT16_t_MAX * 110).toFixed(2);

​

    var heatIndex = computeHeatIndex(dhtTemp, dhtHum, false).toFixed(2);;

​

    var result = [

        //Replace with your own payload parse

        {

            "key": "moduleTemp",

            "value": moduleTemp

        }, {

            "key": "dhtTemp",

            "value": dhtTemp

        }, {

            "key": "dhtHum",

            "value": dhtHum

        }, {

            "key": "heatIndex",

            "value": heatIndex

        }

    ]

    callback(null, result)

}

​

function computeHeatIndex(temperature, percentHumidity, isFahrenheit) {

    // Using both Rothfusz and Steadman's equations

    // http://www.wpc.ncep.noaa.gov/html/heatindex_equation.shtml

    var hi;

​

    if (!isFahrenheit)

        temperature = convertCtoF(temperature);

​

    hi = 0.5 * (temperature + 61.0 + ((temperature - 68.0) * 1.2) + (percentHumidity * 0.094));

​

    if (hi > 79) {

        hi = -42.379 +

            2.04901523 * temperature +

            10.14333127 * percentHumidity +

            -0.22475541 * temperature * percentHumidity +

            -0.00683783 * pow(temperature, 2) +

            -0.05481717 * pow(percentHumidity, 2) +

            0.00122874 * pow(temperature, 2) * percentHumidity +

            0.00085282 * temperature * pow(percentHumidity, 2) +

            -0.00000199 * pow(temperature, 2) * pow(percentHumidity, 2);

​

        if ((percentHumidity < 13) && (temperature >= 80.0) && (temperature <= 112.0))

            hi -= ((13.0 - percentHumidity) * 0.25) * sqrt((17.0 - abs(temperature - 95.0)) * 0.05882);

​

        else if ((percentHumidity > 85.0) && (temperature >= 80.0) && (temperature <= 87.0))

            hi += ((percentHumidity - 85.0) * 0.1) * ((87.0 - temperature) * 0.2);

    }

​

    return isFahrenheit ? hi : convertFtoC(hi);

}

​

function convertFtoC(f) {

    return (f - 32) * 0.55555;

}

​

function convertCtoF(c) {

    return c * 1.8 + 32;

}