hexdump.js

#!/usr/bin/env node

"use strict";
const programName = "tibHexDumper";
const programPid = process.pid;

const format = require('date-fns/format');
const mqtt = require("mqtt");
const fs = require("fs");
const yaml = require("yamljs");
//const { StringDecoder } = require('node:string_decoder');

const configFile = "./config.yaml";
// Load broker and topics preferences from config file
const C = yaml.load(configFile);

function now() {
  let now = new Date();
  // Get rid of AM/PM
  //return now.toLocaleTimeString().split(' ')[0];
  return format(now, "yyyy-MM-dd'T'HH:mm").toString()
}

function match() {
  let now = new Date();
  return format(now, "yyyy-MM-dd'T'HH:mm:ss").toString().split('T')[1].substr(4,4);
}

function hex2Dec(str) {
  return parseInt(str, 16)
}

let pulse = {
  init: function () {
    pulse.debug = true;
    if (C.mqttBroker === null) {
      console.log("\nBroker IP address or hostname missing");
      console.log("Edit your \"config.yaml\" file\n");
      process.exit(0);
    }

    pulse.broker = C.mqttBroker + ":" + C.brokerPort;
    pulse.mqttOptions = {
      username: C.userName, password: C.password,
      will: {
        topic: C.pubNotice, payload: C.willMessage,
      }
    };

    pulse.client = mqtt.connect("mqtt://" + pulse.broker, pulse.mqttOptions);
    pulse.client.on("error", function (err) {
      if (err.errno === "ENOTFOUND") {
        console.log("\nNot connectd to broker");
        console.log("Check your \"config.yaml\" file\n")
        process.exit(0);
      } else
        console.log("Client error: ", err);
    });

    pulse.client.on("connect", function () {
      pulse.client.subscribe(C.topic, function (err) {
        if (err) { console.log("Subscription error"); }
      });
    });

    if (!fs.existsSync('./hex')) {
      fs.mkdirSync('./hex',0x0744);
    }
  }, // init()

  run: function () {
    let elements = 0;
    pulse.client.on("message", function (topic, message) {
      if (topic === "tibber") {
        let buf = Buffer.from(message);
        // JSON data
        if (buf[0] === 0x7b) { // 0x7b, 123, "{" = Pulse status
        }
        // Raw buffer meter data
        else if (buf[0] === 0x7e) {  // 0x7e, 126, "~"
          let hex = buf.toString('hex').toUpperCase();
          let index = hex.indexOf("FF800000") + 8;
          elements = hex2Dec(hex.substr((index + 2), 2))
          if (elements === 18) {
            fs.writeFileSync("./hex/list-" + now() + ".hex", hex);
          } else {
            //console.log('match:', match()); 
            //console.log("./hex/list-" + now() + ".hex");
	    if( match() == '0:00'|| match() == '0:01' ) { //|| or match() == '0:02) {
              fs.writeFileSync("./hex/list-" + now() + ".hex", hex);
              //console.log(hex)
            }
          }
        } // End raw buffer meter data 
      } // topic === "tibber"
    }); // client.on(message)
  } // run ()
}; // pulse()

pulse.init();
pulse.run();