SIG/GPS/SIGFOX/SigfoxParse.js

(function bin_dec() {
    var x = WScript.arguments(0);
    var valor = x.toString();
    var result = parseSigFox(valor);

    WScript.echo(result);
})();

//In an attempt to make the code clearer, I will not be using ArrayBuffer 
function hex2Bytes(val) {

    if (!val) {
        return [];
    }

    var numBytes = val.length / 2;
    var bytes = [];

    for (var i = 0; i < numBytes; i++) {
        bytes.push(parseInt(val.substring(i*2, (i*2) + 2), 16));
    }

    return bytes;
}

function parseLittleEndianInt32(buffer, offset) {
    return (buffer[offset + 3] << 24) +
        (buffer[offset + 2] << 16) +
        (buffer[offset + 1] << 8) +
        (buffer[offset]);
}

function parseLittleEndianInt16(buffer, offset) {
    return (buffer[offset + 1] << 8) +
        (buffer[offset]);
}

function parseLittleEndianInt16Bits(buffer, offset, bitOffset, bitLength) {
    var temp = parseLittleEndianInt16(buffer, offset);
    temp = temp >> bitOffset;
    var mask = 0xffff >> (16 - bitLength);
    return temp & mask;
}

function parseSigFox(data) {
    var buffer = hex2Bytes(data);

    if (!buffer) {
        return null;
    }

    var recordType = buffer[0] & 0x0f;

    switch (recordType) {
        case 0: //positional data
            return parsePositionalData(buffer);

        case 1: //downlink ACK
            return parseDownlinkAck(buffer);

        case 2: //device data
            return parseDeviceStats(buffer);
            
        case 3: //extended positional data
            return parseExtendedData(buffer);

        default:
            return null;
    }
}

function parsePositionalData(buffer) {
    var flags = buffer[0] & 0xF0;
    var inTrip = (flags & 0x10) > 0;
    var lastFixFailed = (flags & 0x20) > 0;

    var latitudeRaw = parseLittleEndianInt32(buffer, 1);
    var longitudeRaw = parseLittleEndianInt32(buffer, 5);
    var headingRaw = buffer[9];
    var speedRaw = buffer[10];
    var batteryRaw = buffer[11];

    var retorno = {
        MessageType: 0,
        InTrip: inTrip,
        LastFixFailed: lastFixFailed,
        Latitude: latitudeRaw * 1e-7,
        Longitude: longitudeRaw * 1e-7,
        Heading: headingRaw * 2,
        SpeedKmH: speedRaw,
        BatteryVoltage: (batteryRaw * 25) / 1000.0
    };
    return "{MessageType: " + retorno.MessageType + ", InTrip: " + retorno.InTrip + ", LastFixFailed: " + retorno.LastFixFailed + ", Latitude: " + retorno.Latitude + ", Longitude: " + retorno.Longitude + ", SpeedKmH: " + retorno.SpeedKmH + ", BatteryVoltage: " + retorno.BatteryVoltage + ", Heading: " + retorno.Heading + "}";
}

function parseDownlinkAck(buffer) {
    var flags = buffer[0] & 0xF0;
    var downlinkAccepted = (flags & 0x10) > 0;

    var firmwareMajor = buffer[2];
    var firmwareMinor = buffer[3];

    var data = [];
    for (var i = 0; i < 8; i++) {
        data.push(i + 4);
    }

    var retorno = {
        MessageType: 1,
        DownlinkAccepted: downlinkAccepted,
        FirmwareVersion: firmwareMajor + '.' + firmwareMinor,
        DownlinkData: data
    };
    return "{MessageType: " + retorno.MessageType + ", DownlinkAccepted: " + retorno.DownlinkAccepted + ", FirmwareVersion: " + retorno.FirmwareVersion + ", DownlinkData: " + retorno.DownlinkData + "}";
}

function parseDeviceStats(buffer) {
    var uptimeWeeks = parseLittleEndianInt16Bits(buffer, 0, 4, 9/*bits*/);
    var txCountRaw = parseLittleEndianInt16Bits(buffer, 1, 5, 11 /*bits*/);
    var rxCountRaw = buffer[3];
    var tripCountRaw = parseLittleEndianInt16Bits(buffer, 4, 0, 13 /*bits*/);
    var gpsSuccessRaw = parseLittleEndianInt16Bits(buffer, 5, 5, 10 /*bits*/);
    var gpsFailuresRaw = parseLittleEndianInt16Bits(buffer, 6, 7, 8 /*bits*/);
    var averageFixTime = parseLittleEndianInt16Bits(buffer, 7, 7, 9/*bits*/);
    var averageFailTime = parseLittleEndianInt16Bits(buffer, 9, 0, 9/*bits*/);
    var averageFreshenTime = parseLittleEndianInt16Bits(buffer, 10, 1, 8/*bits*/);
    var wakeupsPerTrip = buffer[11] >> 1;
    

    var retorno = {
        MessageType: 2,
        UptimeWeeks: uptimeWeeks,
        TxCount: txCountRaw * 32,
        RxCount: rxCountRaw * 32,
        TripCount: tripCountRaw,
        GpsSuccessCount: gpsSuccessRaw * 32,
        GpsFailureCount: gpsFailuresRaw * 32,
        AverageFixTimeSeconds: averageFixTime,
        AverageFailTimeSeconds: averageFailTime,
        AverageFreshenTimeSeconds: averageFreshenTime,
        WakeUpsPerTrip: wakeupsPerTrip
    };

    return "{MessageType: " + retorno.MessageType + ", UptimeWeeks: " + retorno.UptimeWeeks + ", TxCount: " + retorno.TxCount + ", RxCount: " + retorno.RxCount + "}";
}

function parseExtendedData(buffer) {
    var headingRaw = buffer[0] >> 4;
    var latitudeRaw = buffer[1] + buffer[2] * 256 + buffer[3] * 65536;
    if (latitudeRaw >= 0x800000)    // 2^23
        latitudeRaw -= 0x1000000;   // 2^24
    var longitudeRaw = buffer[4] + buffer[5] * 256 + buffer[6] * 65536;
    if (longitudeRaw >= 0x800000)   // 2^23
        longitudeRaw -= 0x1000000;  // 2^24
    var posAccRaw = buffer[7];
    var batteryRaw = buffer[8];
    var speedRaw = buffer[9] & 0x3F;
    var inTrip = (buffer[9] & 0x40) > 0;
    var lastFixFailed = (buffer[9] & 0x80) > 0;

    var retorno = {
        MessageType: 3,
        Heading: headingRaw * 22.5,
        Latitude: (latitudeRaw * 256) / 1e7,
        Longitude: (longitudeRaw * 256) / 1e7,
        PosAccM: posAccRaw * 1,
        BatteryVoltage: (batteryRaw * 25) / 1000.0,
        SpeedKmH: speedRaw * 2.5,
        InTrip: inTrip,
        LastFixFailed: lastFixFailed
    };
    return "{MessageType: " + retorno.MessageType + ", InTrip: " + retorno.InTrip + ", LastFixFailed: " + retorno.LastFixFailed + ", Latitude: " + retorno.Latitude + ", Longitude: " + retorno.Longitude + ", PosAccM: " + retorno.PosAccM + ", SpeedKmH: " + retorno.SpeedKmH + ", BatteryVoltage: " + retorno.BatteryVoltage + ", Heading: " + retorno.Heading + "}";
}