Helios-P Drucksensor Dataconverter .js

Helios-P Drucksensor Payload Decoder LoRaWAN®

function decodeUplink(input) {

    function uncomplement(val, bitwidth) {
        var isnegative = val & (1 << (bitwidth - 1));
        var boundary = (1 << bitwidth);
        var minval = -boundary;
        var mask = boundary - 1;
        return isnegative ? minval + (val & mask) : val;
    }

    var decoded = {};
    var bytes = input.bytes;

    if (input.fPort == 1) { // TELEMETRY

        // decode header
        decoded.base_id = bytes[0] >> 4;
        decoded.major_version = bytes[0] & 0x0F;
        decoded.minor_version = bytes[1] >> 4;
        decoded.product_version = bytes[1] & 0x0F;
        decoded.up_cnt = bytes[2];
        decoded.battery_voltage = ((bytes[3] << 8) | bytes[4]) / 1000.0;              
        decoded.internal_temperature = bytes[5] - 128;

        // Reason of this uplink
        // reasonRaw & 0x01 -> Regular send period
        // reasonRaw & 0x02 -> Measured delta exceeds threshold
        // reasonRaw & 0x04 -> Critical Alarm
        decoded.reasonRaw = bytes[6];

        // Alarm flags
        // alarmRaw & 0x01 -> Pressure low
        // alarmRaw & 0x02 -> Pressure high
        // alarmRaw & 0x04 -> Pressure critical
        // alarmRaw & 0x10 -> Temperature low
        // alarmRaw & 0x20 -> Temperature high
        // alarmRaw & 0x40 -> Temperature critical
        decoded.alarmRaw = bytes[7];

        // Pressure reading status
        // OK = 0
        // ERROR_PROBE = 1
        // ERROR_ADC = 2
        // ERROR_VALUE = 3
        decoded.status = bytes[8];

        // Pressure in mBar
        decoded.pressure = (bytes[9] << 8) | bytes[10];
    }

    return {
        data: decoded,
        warnings: [],
        errors: []
    };
}