Roomtemperature with DS18B20

Chiggo

Hello everybody,

I am new to this forum and I am trying to display the roomtemperature with a DS18B20 sensor at my MagicMirrorv2.

I have installed ‘ds18x20’ to get the temperature using node.js, butit seems to be impossible for me, to display this at my MagicMirror.
I can read the temp using this commands, and it shows the temp at the console.

var sensor = require('ds18x20');
var temp = sensor.get('28-00000574c791');
console.log(temp);

I tried to write a module from exsting code to display the temp at the mirror, but everything it shows is this picture

Here is the code

/* global Module */
/* Magic Mirror
 * Module: MMM-Temperature
 */

Module.register('MMM-Temperature', {
// Define start sequence.
        start: function() {
                Log.info("Starting module: " + this.name);
                // Schedule update interval.
                var self = this;
                setInterval(function() {
                        self.updateDom();
                }, 1000);
},

// Get temperature.
tempRead: function() {
        var sensor = require ('ds18x20');
        var temp = sensor.get('28-04163746c8ff');
        return temp;
},


// Override dom generator.
        getDom: function() {
var temperature = this.tempRead();

var celsius = document.createTextNode(temperature);
var wrapper = document.createElement("div");
wrapper.appendChild(celsius);
return wrapper;
}
});

Can someone explain to me, how to get this thing working!?

MichMich

What is important to understand, is the difference between the frontend module, and the node_helper.

The frontend module (yourmodulename.js) is there to make sure the UI works, the node helper (node_helper.js) allows you to execute commands like you want.

You need to make a module that contains both.

Check out this very simple example which is pretty easy for you to adapt:
https://github.com/MichMich/mmm-systemtemperature

MichMich

To point you a bit more in the right direction, the node helper should change to something like:

...
sendTemperature: function() {
	var temp = sensor.get('28-04163746c8ff');
	this.sendSocketNotification('TEMPERATURE', temp);
}
...

Chiggo

Thank you for fast reply.

I will give it a try tomorrow and check if i get it.
My first steps in JS :sweat_smile:

Chiggo

Spend some time to figure out what you mean, but i stuck again.
Now at this point

Here is the MMM-Temperature.js

Module.register('MMM-Temperature', {

        defaults: {
                prependString: 'Raumtemperatur: '
        },


        start: function() {
                this.temperature = 'fetching...';
                this.sendSocketNotification('CONNECT');
        },


        socketNotificationReceived: function(notification, temp) {
            if (notification === 'TEMPERATURE') {
                this.temperature = temp;
                this.updateDom();
            }
        },


        // Override dom generator.
        getDom: function() {
                var wrapper = document.createElement("div");
                wrapper.innerHTML = this.config.prependString + this.temperature;
                return wrapper;
        },

});

And here is the node_helper.js

var NodeHelper = require("node_helper");
var sensor = require('ds18x20');


 module.exports = NodeHelper.create({
        start: function function_name () {
                var self = this;
                setInterval(function() {
                        self.sendTemperature();
                }, 10000);
        },


        sendTemperature: function() {
                var self = this;
                var temp = sensor.get('28-04163746c8ff');
                self.sendSocketNotification('TEMPERATURE', temp);
        },
 });

It seems that the MMM-Temperature module is not trying to call the node_helper.js
Not sure why it doesn’t. Or even if, i don’t know why the node_helper.js doesn’t work.

Maybe this has something to do with the "sendSocketNotification(‘CONNECT’) ???
It’s never mentioned in the node_helper.

Chiggo

It works!

after testing some things PM2 didn’t work anymore, so i recovered from a backup, installed the drivers for the DS18B20 again, copied the scripts back, restarted and it works.

Don’t know why and how, but it does :smile:

Solved!

Phate

@Chiggo

This sounds awesome…

Is this downloadable from github?

Chiggo

@Phate

No, it’s not available on GitHub. But with the hints from @MichMich it was pretty easy to realize.

To load the drivers for the DS18B20 I followed these instructions https://www.kompf.de/weather/pionewiremini.html

To get the DS18B20 working with node.js I installed this https://www.npmjs.com/package/ds18x20

And finaly I edited the scripts of the systemtemperature-module and it works.

Step-by-Step

Add this line to your /boot/config.txt

dtoverlay=w1-gpio,gpiopin=4,pullup=on

Add to your /etc/modules following and reboot the Pi

w1-gpio pullup=1 
w1-therm

Note the ID of your sensor (go to /sys/bus/w1/devices and list the files, the ID should look something like this 28-04163746c8ff
Got to /MagicMirror/modules and create a folder named MMM-Temperature
Create a file named MMM-Temperature.js and copy the code from my post for this script
Create a file named node_helper.js and copy the code from my post and change the ID of my sensor to yours (it’s in line 16)
Register this module in your /MagicMirror/config/config.js
Restart your MM and you are done :)

Hope I could help. Let me know if it works.

Phate

@Chiggo

Mate. That’s just awesome.

Few worry spots but sure I can make that happen.

I made sure to order the same temp module so hopefully I shouldn’t have trouble.

Thanks mate. Awesome.

May have questions tho so will yell out of i do when eBay comes thru lol

Thanks again

A Former User

This post is deleted!