MagicMirror and adruino over ethernet

[Kereknjek]

I think that this is way to extensive for my knowledge. I can’t make heads or tails out of it…

[sdetweil]

@Kereknjek basically the arduino sends text strings with Serial.println(“[COMMAND:NAME:DATA]”)

To transmit a sensor data to the module: `[sensor:SENSOR_NAME:SENSOR_VALUE]**

Example:

Serial.println(“[sensor:MQ2:19]”);
Serial.println(“[sensor:LM35:11]”);
Serial.println(“[sensor:HCSR04:64]”);

but anyhow, lots of work in the arduino code to make this work

[Kereknjek]

@sdetweil
That part is perfectly clear.

Here is C/P of what I am using now:

      client.println("< !DOCTYPE HTML >");
      client.println("< html >");
      client.print("Napon panela: ");
      client.print(PanelU);
      client.println(" V < br/>");
      client.print("Struja panela: ");
      client.print(PanelI);
      client.println(" A < br/>");
      client.print("Napon baterije: ");
      client.print(BatU);
      client.println(" V < br/>");

.
.
.
client.println(“< / html >”);

That is slightly modified ethernet server sample program from ethernet library.

Edit: had to add spaces because html wasn’t showing.

[BD0G]

This may be a stupid question , but . Why not just use the MMM-iFrame Module since the information is already provided /served from a webserver within the Arduino? You can change the size of the iFrame that displays the Url so that it can be small and take up just a little of the magic mirror or large and fill the mirror. Since you will not be touching the screen to change or interact with the data.

[Kereknjek]

It’s not stupid question.

If arduino serves webpage, it should be served from sd card.
To use sd card, you have to use sd card library, make decisions wether client wants whole web page or just data packets…
All that takes a lot of memory and time to process. And arduino is slow and low on memory compared to RPi.
For arduino is much simpler to detect “give me data” and send sensor ID and value.

Plus, in my case, arduino mega has 16 amperemeters to read and 18 outputs to regulate.
I wouldn’t like it if it gets stuck in code while inverter is working at full capacity. It could become fire hazard.

[BD0G]

@Kereknjek So in a nutshell. Yes the Arduino can serve a whole webpage of data , but it will take a long time. If one just sends the data from the Arduino to the Raspberry Pi then the Raspberry Pi can display the webpage faster as its processor and potentially memory is faster.

[Kereknjek]

Yes. Plus, if I would want to make any modifications to webpage, first I would have to shutdown arduino and whole solar system, pull sd card out, modify page, plug sd card back in and restart sytem.

If sd card gets damaged in any way or get slow for some reason (had one like that on my 3D printer), whole system running on that arduino gets slow and unuseable.

[sdetweil]

@Kereknjek cool. You could make a little change and have it return just data.

If the path is sensor1, send just sensor1’s data. Etc.

Pretty easy, just a case stmt… you could make it json data pretty easy too…

The request could ask for a sensor or block of sensors, and send raw data.

[sdetweil]

On my Arduino measuring water flow and water volume. I did those in interrupt and timer routines. And sent data in the main path.

[BD0G]

@Kereknjek Sounds like you need to backup the entire SD Card of your Arduino and create an image for safe keeping. If you Download Win32 Disk Imager you can create an image of the entire SD card and write it to a hard drive. Then if catastrophe strikes simply remove the SD card and use Win 32 Disk Imager to write the working image back to the SD card.

It can be downloaded here Win32DiskImager

[sdetweil]

@BD0G my 8266 has onboard flash ram. No SD card required.

[BD0G]

@sdetweil Was referring to @Kereknjek and recommending he backup the SD card on the Arduino that is working for safe keeping.

I have an 8266 as well ! Its dedicated to my smartblinds control that I control via smarthings and a custom 3 D printed enclosure for a servo that mounts in the top rail of the blinds. Works splendidly!

[sdetweil]

@BD0G I agree, backup is an important strategy. I found out the other day SD cards have a limited life, determined by number of writes…

[Kereknjek]

@sdetweil said in MagicMirror and adruino over ethernet:

@Kereknjek cool. You could make a little change and have it return just data.

If the path is sensor1, send just sensor1’s data. Etc.

Pretty easy, just a case stmt… you could make it json data pretty easy too…

The request could ask for a sensor or block of sensors, and send raw data.

Yes! That is what i’m looking for.
But discussion went to arduino side.
My problem is that I don’t know how to do it at magic mirror side.

[sdetweil]

@Kereknjek ok. More later. Grandson on site!

[sdetweil]

@Kereknjek so. the methods to get data from server (web site http://something) is request()

there are different forms XMLRequest, request… XMLRequest is builtin to the browser that MM runs on (either Electron, or Chrome)

the design of the MM module is in two parts… the part that runs in the browser, and renders the data
this javascript file name matches the module name.

module = someModule, folder = someModule, filename = someModule.js
the ‘module’. js cannot use ‘require’() to load additional scripts… but SOME can be loaded
thru the mm callback at function getScripts()
for builtins, you can just use them

the processing model, is get your data, then call this.updateDom(somedelaytime), to tell MM that new data for your module is ready. the MM runtime will call you modules getDom() function to allow you to construct the html object tree of content to inject into the single page DOM, in the position[modulename] div…
you can see this tree in the developers windows (ctrl-shift-i, select the elements tab)

in some cases the requirements of the data collection require services that are NOT builtin to the browser, serial port, database, complex api calls, etc… so, the MM design provides for a helper for the module, filename called node_helper.js

it can use require() to load service libraries to access outside datasources, or manipulate data.

the module and helper talk to each other thru one api, sendSocketNotification(item_id, data)
and receiveSocketNotification(item_id, data).
the format of item_id is a string, and data can be any format/ totally up to you how you want to use it.

the info provided in the config.js entry for a module, replaces same named items in the module ‘default{}’ object… BUT this data does NOT get sent to the helper UNLESS YOU DO IT.
a convention, is that the module receives notices from the system via notificationReceived (notice no ‘socket’ in the name)… and when the moduel receives the ‘all_modules_started’ notice, the module sends a pointer to the config block to the helper… so they both have the same copy.

my Sample Module has all the parts, in a working example… but doesn’t do much… send the config down,
waits some time, and sends a configured message back up to the module, and then calls this.updated() to indicate new data is available.

you can use request() in the helper, or XMLRequest() in the module (builtin) XMLRequest will process XML or a string. request() cab be any data format (including binary)…

these calls do EXACTLY the same thing as what your browser does when you put in http://some_ip_address to get the web page from your arduino

[Kereknjek]

@sdetweil
Thank you!
Ill need some time to try it out.

Mechanical or should I say, woodwork is finished. I’m still waiting for short hdmi cable, PIR sensor and hinges I ordered… It looks sexy alredy! Can’t wait to see it working.

[sdetweil]

@Kereknjek i would start slow…

use my sample, send one request, get back content. you cannot put a whole page up unless u open an iframe…

MM is called a Single Page Application… (SPA)…
in this model, each ‘module’ contributes a little content (a div’s worth) and that little bit is injected into the running view of the web page (dom=document object model) again, you can see this layout on the developers window, elements tab

u can do this on your Windows PC too with chrome, press ctrl-shift-i on any page (again to turn it off)