Juno TH TILT Datenkonverter in .js

Hier finden Sie den Decoder für das Juno TH TILT-Modul LoRaWAN®. Er ermöglicht die Dekodierung aller übertragenen Sensordaten.

function Decoder(bytes, port) {
 
    // Conversion of signed integers
    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 = {};
 
    if (port === 1) {
 
        // Attributes
        decoded.base_id         = bytes[0] >> 4;
        decoded.major_version   = bytes[0] & 0x0F;
        decoded.minor_version   = bytes[1] >> 4;
        decoded.product_version = bytes[1] & 0x0F;
 
        // Telemetry
        decoded.up_cnt               = bytes[2];
        decoded.battery_voltage      = ((bytes[3] << 8) | bytes[4]) / 1000.0;
        decoded.internal_temperature = bytes[5] - 128;
        
        var idx = 6;//Start of variable size, version dependent payload section

        if(decoded.product_version & 0x01){//magentic field sensor for operating hours counting
            decoded.operating_seconds = (bytes[idx++] << 24) | (bytes[idx++] << 16) | (bytes[idx++] << 8) | bytes[idx++];
            decoded.cycles = (bytes[idx++] << 24) | (bytes[idx++] << 16) | (bytes[idx++] << 8) | bytes[idx++];
            decoded.utilization_rate = ((bytes[idx++] << 8) | bytes[idx++]) / 100.0;
            decoded.is_active = bytes[idx++];
        }
        if(decoded.product_version & 0x08){//Has Precision TH Sensor
            decoded.temperature = ((bytes[idx++] << 8) | bytes[idx++]) / 10 - 100;
            decoded.humidity = bytes[idx++];
        }

    }else if(port == 197){ //Manual decode of wifi scan for when semtech cloud is not available
      
      var format = bytes[0];
      var offset = 1;
      var results = [];
      var count = 0;
      var i = 0;
      var macBytes;
      var mac;
      
      if (format === 0) {
        // MAC-only format
       // Remaining length should be divisible by 6
        count = Math.floor((bytes.length - offset) / 6);
        for (i = 0; i < count; i++) {
          macBytes = bytes.slice(offset + i*6, offset + i*6 + 6);
          mac = macBytes.map(function(b) {
            return (b < 16 ? "0" : "") + b.toString(16).toUpperCase();
          }).join(":");
          results.push({ mac: mac });
        }
      } else if (format === 1) {
        // MAC+RSSI format
        // Remaining length should be divisible by 7
        count = Math.floor((bytes.length - offset) / 7);
        for (i = 0; i < count; i++) {
          var rssiRaw = bytes[offset + i*7];
          // Convert to signed int8
          var rssi = rssiRaw > 127 ? rssiRaw - 256 : rssiRaw;
          macBytes = bytes.slice(offset + i*7 + 1, offset + i*7 + 7);
          mac = macBytes.map(function(b) {
            return (b < 16 ? "0" : "") + b.toString(16).toUpperCase();
          }).join(":");
          results.push({ mac: mac, rssi: rssi });
        }
      } else {
        return { errors: ["Unknown payload format: " + format] };
      }
    
      decoded.format = format;
      decoded.access_points = results;
      
    }
    
    return decoded;
}

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