UTC Conversion using Function

General
21

This works !!!

could you help me understand if we can use the shift operator to read the data from start to end .
image
instead of the loops that has been used

 
    var newMsg = {};
  
 
 

var data_time =  msg.payload.data.substr(16, 8)  ;
var Temp = Number(hexTo8p8(msg.payload.data.substr(16+8, 4)));
var Humidity = Number(hexTo8p8(msg.payload.data.substr(16 + 8+4, 4)));
var data =  msg.payload.data.substr(16, 8);

  for(var i=1;i<=30;i++)
  {
      data_time = msg.payload.data.substr(16 * i, 8  );
      Temp = Number(hexTo8p8(msg.payload.data.substr(24 * i, 4  )));
      Humidity = Number(hexTo8p8(msg.payload.data.substr(28 * i, 4  )));
      data = msg.payload.data.substr(16 * i, 8 );
      let UTC_ISO = new Date(parseInt(msg.payload.data.substr(16 * i, 8), 16) * 1000).toISOString();
      var converted_payload = UTC_ISO.split(/\.|T/).slice(0, 2).join(" ");
      
      var checktime = 1546337502;
      if(checktime>data_time)
      {

      }

      
      newMsg.payload = [{
        
          time: data_time,
          utc: converted_payload,
 
          temp: Temp,
          humidity: Humidity,
       
      },
      {

          history: 1 
   



      }];
      node.send(newMsg);

 
  }  


 
 
     
        
   
 


return null;

function calculateDistance(rssi) {
    let P = -69; // @TODO This value should come from MQTT message
    let n = 3;
    let d = Math.pow(10, ((P - rssi) / (10 * n))); //(n ranges from 2 to 4)
    return d * 2;
}


function hexTo8p8(/** @type {string} */ value) {
    let intValue = parseInt(value, 16);
    let signed = (intValue & 0x8000) > 0 ? -1/10 : 1;
    return signed * intValue / Math.pow(2, 8);
}



function int2float( /** @type {string} */value_int) {
    // Create new Buffer based on array bytes
    const buf = Buffer.from(value_int);
    // swap the words
    const temp0 = buf[0];
    const temp1 = buf[1];
    buf[0] = buf[2];
    buf[1] = buf[3];
    buf[2] = temp0;
    buf[3] = temp1;

    // Represent these bytes as 32-bit unsigned int
    const value = buf.readInt32BE();

    // save the value
    msg.payload = value;

    return msg;
}
22 
Similarly can we convert it to unix time stamp in the same way ?
23

This looks like a job for node-red-contrib-buffer-parser

24

I think you should probably be using node-red-contrib-buffer-parser to decode your buffer. That node is designed for exactly this sort of issue.

25

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