Python in to the magic mirror.

[paulvanderheijden90]

@sean
1.Try absolute path of your target py script.
( Oke I add the Path )

2.When your child_process.spawn is called, python script will be executed.
( oke that’s Clear.)

3 Well, node_helper.js is also needed. (* the codeYou send me I add in the node_helper.js.
3-1. Add your module into your config.js either. ( Yes I did. The example you send me was working. )
I can print something on the magic mirror on my own build Module.

4 When your python script is executed on the shell, normal stdout will be printed out on the shell.
( Yes this is working wenn I executed on the shell it will print what I give in so that site wil look fine.

So thank you for the answers. Im almost sure the Python project is oke. because it wil “print” thrue the sys.stdout.write function.
This is the Node_helper.js . I think this is fine aswell.

This is the MMM_. Module. im not sure I did this one oke.

And ofcourse I add the config. file.

Can you Please have a look what is going wrong because my magic mirror is now black and I can only restart bij ctrl alt del. so please help.

[A Former User]

@paulvanderheijden90
Your node_helper.js is not correct.

See other’s module as reference.

Or you can get a hint of executing python script in node_helper.js
https://github.com/eouia/MMM-GroveGestures/blob/master/node_helper.js
(I’m using PythonShell instead child_process in that module.)

[sdetweil]

@paulvanderheijden90 start the mirror in developer mode

npm start dev

and look at the console tab for errors (red text)

now in your node_helper spawn data.on() routine, you need to add a sendSocketNotification(:I_DID", some_data) to get the info to the Module.js socketNotificationReceived() method so you can do something to display it (call updateDom(), which will schedule a call to getDom()

[paulvanderheijden90]

@sean said in Python in to the magic mirror.:

@paulvanderheijden90
Your node_helper.js is not correct.

Hello Sean,
Why is it wrong? I copy it from your post earlier.
I started in Dev mode. I noticed that wenn I add the Node_helper.js module in the MMM-P2000 map the Magic mirror crashes and give only black screen.
I studyed the Node_helper file. I see in the first line you define the function and in the second line you define the settings for that function. So that’s clear to me. In the next lines you define the stdout of the process and copy it in de Console Log. so that’s also clear for me. So I down’t know why is it not working and crashes.

I made in the same map ( home/pi/src/ ) a file called test.py Here I defined a string and I write the string to the stdout so as you say before the python project don’t need a separate call. So that should work as well.

Node_helper.js:

Python project:

I also getting in to the module setup so I changed the MMM-P2000.js and I think it is oke like this.
First the start function restart every 1000mS the dom function.
then the getdom Function is now showing the test “Hello World” in the module
so that should be oke aswell. I

How do I need to link the socked notification message to the Module string?

[sdetweil]

@paulvanderheijden90 node helper needs to look like this
see the doc here https://github.com/MichMich/MagicMirror/tree/master/modules#the-node-helper-node_helperjs

const NodeHelper = require('node_helper');

// any other imports (javascript require)

module.exports = NodeHelper.create({
   // local variables 
    self: 0,
		pins_loaded:[],
		pin_index:0,
		results:{},
		using_chartjs: true,
		suspended: false,
		timer:null,

    start: function() {
        console.log("Starting module: " + this.name);
        self = this;
    },
 socketNotificationReceived: function(notification, payload) {
        // usually the module send the config data down to the node_helper
        if (notification === 'CONFIG') {
            this.config = payload;
        }

// any other functions, u need, note, after each function is a ',' (comma)
}
});

[A Former User]

node_helper.js is helper script of your module to use various features of NodeJS. your main module script(MMM-P2000.js) is just front-end javascript on Browser(Electron/Chromium). So when you need more features which are not supported on browser level, use node_helper.js

MMM-P2000.js and node_helper.js can communicate with each other by socketNotification.

you need to make proper node_helper.js which could be used in MM framework.

Usual format is

var NodeHelper = require("node_helper")

module.exports = NodeHelper.create({
  start: function() {
    // ...
  },
  socketNotificationReceived: function(notification, payload) {
    // ...
  },
})

There are two entry points in node_helper.js from your main module .

start will be called when MM is executed and your module is loaded. Usually you can prepare things here.

socektNotificationReceived will be called when your main module send socketNotification with sendSocketNotification.

With this, you can transfer config values, specific datas or order to do something.

Your current MMM-P2000.js is not so good to use. I recommend you continue to read my https://forum.magicmirror.builders/topic/8534/head-first-developing-mm-module-for-extreme-beginners more.

[paulvanderheijden90]

I changed the Node_helper.js:

But the minute I run the Start dev I get white screens. so im not able to debug anything.
Can I get a hand ?

[sdetweil]

the spawn stuff needs to be INSIDE the node helper…

probably called in Start or in the socketNotificationReceived, when the config is sent down from the module…

[paulvanderheijden90]

@sdetweil Thank you for you’re information.
I changed it like you said but unfortunly still get the With screens.

[A Former User]

@paulvanderheijden90
If possible, Instead image, post code itself.
Anyway, You’d better to read docs more carefully.

MMM-P2000.js

/// MMM-P2000.js

Module.register("MMM-P2000", {
  getDom: function() {
    var e = document.createElement("div")
    e.id = "DISPLAY"
    return e
  },
  notificationReceived: function(notification, payload, sender) {
    switch(notification) {
      case "DOM_OBJECTS_CREATED":
        var timer = setInterval(()=>{
          this.sendSocketNotification("GIVE_ME_DATA")
        }, 1000)
        break
    }
  },
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "HERE_IS_DATA":
        var e = document.getElementById("DISPLAY")
        e.innerHTML = payload
        break
    }
  },
})

node_helper.js

/// node_helper.js
const spawn = require("child_process").spawn
var NodeHelper = require("node_helper")

module.exports = NodeHelper.create({
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "GIVE_ME_DATA":
        this.job()
        break
    }
  },
  job: function() {
    var process = spawn("python", ["/home/pi/src/test.py"])
    process.stdout.on("data", (data)=>{
      console.log(data)
      this.sendSocketNotification("HERE_IS_DATA", data)
    })
  }
})

I didn’t test. I wrote this code with only my brain. so there could be errors, but you can catch the concept.

[paulvanderheijden90]

@Sean Thank you very much im going to check the code and see if I can implement it in the magic mirror.
Thank you I will let you know

[paulvanderheijden90]

@sean
Hello Sean, Again thank you very much for you’re valued help!.

I spend yesterday after midday and evening with a friend figure out how you’re code is working. and we did some tests to send also somthing back to the Node helper and alote came clear by you’re example.
So realy thank u very much.

To day I spend my morning figure out one last problem the text on the screen is [ Object ArrayBuffer] and not the string I put true the stdout.write.
The text that is displayed on the screen is :

I did some debugging of my own. and wenn I override the data in the node helper just after it come from the spawn function this is displayed on the mirror. so the code is working until the spawn function.

/// node_helper.js

const spawn = require("child_process").spawn

var NodeHelper = require("node_helper")



module.exports = NodeHelper.create({

  socketNotificationReceived: function(notification, payload) {

    switch(notification) {

      case "GIVE_ME_DATA":

        this.job()

        break

    }

  },

  job: function() {

    var process = spawn("python", ["/home/pi/src/test.py"])

    process.stdout.on("data", (data)=>{
	data= "test hello World"
      console.log(data)

      this.sendSocketNotification("HERE_IS_DATA", data)

    })

  }

})

So i tested also the python test project. and wenn I run it in the terminal it give no error. so the python project is fine aswell I think.

import sys


sys.stdout.write("Hallo Ik ben Paul")

So I think the spawn function is not correct at this time?
Can you help me out one more time please?

[A Former User]

@paulvanderheijden90 said in Python in to the magic mirror.:

Object ArrayBuffer

is one of javascript Object type. not text itself. (Sorry for my prior example. it needs to be converted from Object to HTMLText.)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer

process.stdout.on("data", (data)=>{
  console.log(data) 
  // You can see the structure of this `data` object(ArrayBuffer) on the shell terminal.

  var result = String.fromCharCode.apply(null, new Uint16Array((data))
  // You need to convert or filter or manipulate `data` object whatever for your real usage.

  this.sendSocketNotification("HERE_IS_DATA", result)
 })

[paulvanderheijden90]

@Sean Hello Sean,
I was thinking somting was wrong because I see the buffer printing in the terminal showing:

Buffer 48 61 6c 6c 6f 20 49 6b 20 62 65 6e 20 50 61 75 6c>

i was trying to figure out the text line that it was representing but it was not showing something.

So im happy you came up with the solution for the buffer.

Unfortunly wenn at the var result code the magic mirror is crashing again and im not able to debug.
Can you please heave a look at it

/// node_helper.js

const spawn = require("child_process").spawn

var NodeHelper = require("node_helper")



module.exports = NodeHelper.create({

  socketNotificationReceived: function(notification, payload) {

    switch(notification) {

      case "GIVE_ME_DATA":

        this.job()

        break

    }

  },

  job: function() {

    var process = spawn("python", ["/home/pi/src/test.py"])

    process.stdout.on("data", (data)=>{
	
      console.log(data)

      var result = String.fromCharCode.apply(null, new Uint16Array((data))

      this.sendSocketNotification("HERE_IS_DATA", result)

    })

  }

[A Former User]

@paulvanderheijden90
Crashing? show me the error log.

[paulvanderheijden90]

@sean said in Python in to the magic mirror.:

Crashing? show me th

App threw an error during load
/home/pi/MagicMirror/modules/MMM-P2000/node_helper.js:76
}.call(this, exports, require, module, __filename, __dirname); });
                                                            ^

SyntaxError: missing ) after argument list
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:606:28)
    at Object.Module._extensions..js (module.js:653:10)
    at Module.load (module.js:561:32)
    at tryModuleLoad (module.js:504:12)
    at Function.Module._load (module.js:496:3)
    at Module.require (module.js:586:17)
    at require (internal/module.js:11:18)
    at loadModule (/home/pi/MagicMirror/js/app.js:127:17)
Whoops! There was an uncaught exception...
/home/pi/MagicMirror/modules/MMM-P2000/node_helper.js:76
}.call(this, exports, require, module, __filename, __dirname); });
                                                            ^

SyntaxError: missing ) after argument list
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:606:28)
    at Object.Module._extensions..js (module.js:653:10)
    at Module.load (module.js:561:32)
    at tryModuleLoad (module.js:504:12)
    at Function.Module._load (module.js:496:3)
    at Module.require (module.js:586:17)
    at require (internal/module.js:11:18)
    at loadModule (/home/pi/MagicMirror/js/app.js:127:17)
MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues
Launching application.

[A Former User]

@paulvanderheijden90 said in Python in to the magic mirror.:
Your log is telling you what is wrong.
See the 76 line of node_helper.js. There could be missing ) after argument list.

[paulvanderheijden90]

@sean So sorry you’re totally right… I was little bit confused by all the “at” conclusens.
Im sorry I could had fixed that. And I did !

Now it is working !!!
So very nice ! im going to put this in my P2000 Raspberry python Programma. and will heave a lot of play with it.

I will post/ show you the and result !

[paulvanderheijden90]

Hello @Sean,
Again thank you for the help. As I say after your help it was possible for me to “print” a string variable on the magic mirror module through python.
But is was not able to put my P2000 alarm from the fire department on my screen. I noticed that it was a problem in the python script of the alarm.
I used the stdout.write function again. like you told me. but I needed to add the flush function as wel.
so now it is

sys.stdout.write("hallo ik ben Paul")
sys.stdout.flush()

And then it was working !
so thank you and here the result:

[paulvanderheijden90]

@sean
Hello Sean,
like I posted yesterday the app is running now. And it is showing wat I need to display. So im very happy.

But…
After a time ( more after a couple of runs ) the magic mirror app is crashed and freezed. So noting is updating any more.

My feeling is telling that the buffer were I put in the string value is filling up.

wenn i run the python script without the mirror it is running fine.

Please can you give me a help?