Module development - using example of Temperature Nodes with 1-Wire PT100 / DS18B20 Sensor at multiple Locations

3. For the third step, we tidy up the module code with some (extra) documentation.

It is very useful to include in the module code - as comment - some terse documentation about the usage of the module, see example in DS18B20 temperature sensor module. The embedded module documentation/information is at the beginning in block comment.

The usage example is taken from current code. The code to be and to be used as a module -
lines 5..65 - looks like this:

// TemperatureDevTest2.js
require("DS18B20"); // used by the dynamically loaded module
Modules.addCached("Temperature", function() {

/* Copyright (c) 2017 ... */
/*
Module to wrap application of DS18B20 temp sensor module in Temperature class

` ` `
var oneWire = new OneWire(B8);
var Temperature = require("Temperature");
var ts1 = new Temperature
  ( "office" // name / location of temperatre sensor 1
  , oneWire
  , null     // addr on one-wire currently not implemented / used
  , 5000     // every 5 secs make a read (to keep it not booring)
  , "F"      // preferred unit is Fahrenheit
  );
var temp = 0;
setTimeout() { function() {
  var tempTemp = ts1.getTemp(); // get temperature,...
  if (tempTemp != temp) {       // ... if changed from last time,...
    temp = tempTemp;            // ... hold on to it and...
    console.log(new Date() + ": " + temp; // ...print it;...
  } }, 10000); // ...every ten seconds // ...do this every 10 seconds
` ` `
 */

// Temperature 'class'/prototype definition
var Temperature = function // module (class), for multiple instances
  ( name      // name hinting room / location of sensor\
  , oneWire   // one-wire; for example: new OneWire(B8);
  , addr      // address on the one-wire (required for multiples)
  , interval  // interval in milliseconds of measurements
  , preferred // optional, unit - "C" or "F" (default and not F is C)
  ) {
  // set givens
  this.name       = name;
  this.oneWire    = oneWire;
  this.addr       = addr;
  this.interval   = interval;
  this.preferred  = (preferred==="F") ? "F" : "C";
  this.enabled    = (typeof enabled === "undefined") || enabled;
  this.t = (this.preferred==="C") ? 0 : 32; // set current to 'frozen'
  this.intervalId = null; // later also used as indicator for enabled
  this.sensor     = null; // laster also used as indicatore for connected
  // get going
  this.sensor = require("DS18B20").connect(this.oneWire)­;
  this.intervalId = setInterval(function(_this) {
      _this.sensor.getTemp(function(t) {
      _this.t = t;
    });
  }, this.interval, this);
};
Temperature.prototype.getTemp = function
( unit // optional, unit "F" or "C", default "C"
) {
  var u = ((typeof unit !== "undefined") && (unit === "F")) ? "F" : "C";
  var d = (u === "F")
    ? (this.t * 1.8) + " Fahrenheit"
    : this.t + " Celsius";
  return d;
};

exports = Temperature;

});

// usage
// setup oneWire
var oneWire = new OneWire(B8);
// setup 1st temperature sensor ts1
var Temperature = require("Temperature");
var ts1 = new Temperature
  ( "office" // name / location of temperatre sensor 1
  , oneWire
  , null     // addr on one-wire currently not implemented / used
  , 5000     // every 5 secs make a read (to keep it not booring)
  , "F"      // preferred unit is Fahrenheit
  );
// for sample's sake, do everhthing deferred for more 
// than 5 seconds in order to have value(s) to display
setTimeout(function(){
// get temp in preferred unit 
console.log(ts1.getTemp());
},6000);