Question

I have a small web server written using node.js, express and serial port which would constantly listen to an temperature sensor attached to the mac via USB. The code is as follow:

var serialport = require("serialport"),       // include the serialport library
    SerialPort  = serialport.SerialPort,      // make a local instance of serial
    app = require('express')(),           // start Express framework
    server = require('http').createServer(app),   // start an HTTP server
    io = require('socket.io').listen(server);   // filter the server using socket.io

var mongo = require('mongodb');

var Server = mongo.Server,
    Db = mongo.Db,
    BSON = mongo.BSONPure;

var server = new Server('localhost', 27017, {auto_reconnect: true});
db = new Db('sensordatabase', server);

db.open(function(err, db) {
  if(!err) {
    console.log("Connected to 'sensordatabase' database");
    db.collection('tempsensor', {safe:true}, function(err, collection) {
      if (err) {
        console.log("The 'values' collection doesn't exist. Creating it with sample data...");
      }
    });
  }
});

var serialData = {};                // object to hold what goes out to the client
server.listen(8080);                // listen for incoming requests on the server
console.log("Listening for new clients on port 8080");

// open the serial port. Change the name to the name of your port, just like in Processing and Arduino:
var myPort = new SerialPort("/dev/cu.usbmodem5d11", { 
// look for return and newline at the end of each data packet:
  parser: serialport.parsers.readline("\r\n") 
});

// respond to web GET requests with the index.html page:
app.get('/', function (request, response) {
  myPort.on('data', function (data) {
    // set the value property of scores to the serial string:
    serialData.value = data;
    response.send(data);
    // for debugging, you should see this in Terminal:
    console.log(data);
  });
});

As it can be seen from the above code, my sensor values are stored in “data”.

Now I would like to save this data into my tempsensor collection which has the following format:

{
    "Physicalentity": "Temperature",
    "Unit": "Celsius",
    "value": "",
    "time": "",
    "date": ""
  },

My question is:

1: How can I save the “data” in the value object, using the mongodb driver for node.js?
2: How can I add the time when the data is added automatically?

I know there’s a function called new Date() for the date, is there a similar function for time?

I would really appreciate any help.

Thanks a ton in advance.

Answer 1

You can do something like this to insert your document into your collection.

db.collection('tempsensor',{safe:true}, function(err, collection) {

collection.insert({
"Physicalentity": "Temperature",
"Unit": "Celsius",
"value": "",
"time": "",
"date": ""
}, function(err, doc) {
  if(err){
     console.log("Error on document insert");
  }else{
     //Document saved succesfuly
     }
  });
});