ttn_payload_formatter_function.js

function decodeUplink(input) {

    var buf_temp = new ArrayBuffer(4);
    var view_temp = new DataView(buf_temp);
    const temp_bytes = input.bytes.slice(0, 4);

    var buf_pres = new ArrayBuffer(4);
    var view_pres = new DataView(buf_pres);
    const pres_bytes = input.bytes.slice(4, 8);

    var buf_hum = new ArrayBuffer(4);
    var view_hum = new DataView(buf_hum);
    const hum_bytes = input.bytes.slice(8, 12);

    var buf_pm10 = new ArrayBuffer(8);
    var view_pm10 = new DataView(buf_pm10);
    const pm10_bytes = input.bytes.slice(12, 20);

    var buf_pm25 = new ArrayBuffer(8);
    var view_pm25 = new DataView(buf_pm25);
    const pm25_bytes = input.bytes.slice(20, 28);

    temp_bytes.forEach(function(b, i) {
        view_temp.setUint8(i, b);
    });

    pres_bytes.forEach(function(b, i) {
        view_pres.setUint8(i, b);
    });

    hum_bytes.forEach(function(b, i) {
        view_hum.setUint8(i, b);
    });

    pm10_bytes.forEach(function(b, i) {
        view_pm10.setUint8(i, b);
    });

    pm25_bytes.forEach(function(b, i) {
        view_pm25.setUint8(i, b);
    });

    //var temp = view_temp.getFloat64(0);
    var temp = view_temp.getInt32(0);
    var pres = view_pres.getInt32(0);
    var hum = view_hum.getInt32(0);
    var pm10 = view_pm10.getFloat64(0);
    var pm25 = view_pm25.getFloat64(0);

    //Варна е на 80м надм. височина
    const above_sea_level = 80;

    var slp = pres + ((pres * 9.80665 * above_sea_level) / (287 * (273 + temp + (above_sea_level / 400))));

    var p25 = Math.round(pm10 * 10) / 10;
    var p10 = Math.round(pm25 * 10) / 10;
    pm10 = p10.toString();
    pm25 = p25.toString();

    return {
        data: {
            id: 1,
            data: [{
                    name: 'bme280',
                    type: "temp_sensor",
                    data: {
                        temperature: temp,
                        actual_pressure: pres,
                        humidity: hum,
                        sea_level_pressure: Math.round(slp)
                    }
                },
                {
                    name: "dust",
                    type: "dust_sensor",
                    data: {
                        pm10: pm10,
                        pm25: pm25
                    }
                }
            ]

        }
    }
}