Processing Forum

Really simplified passing javascript variable to processing.js not working

[1 Reply]
- 27-Jun-2013 08:19 AM
- Forum: Processing with Other Languages
Right,

I am really trying to walk before I can run but still cant get this to work

I have this html file with what seems to me to be valid javascript
1. <!DOCTYPE html>
  <html>
      <head>
        <meta charset="utf-8">
        <title>My Processing Page</title>
        <script type="text/javascript" src="processing-1.4.1.min.js"></script>
        <script type="text/javascript">
  
          instance = Processing.getInstanceById('JSON_Test');
          instance.GetWebData(10.0,11.0,1,2,3,1234567,6,"This is a test");
  
        </script>
      </head>
      <body>
        <canvas id="JSON_Test" data-processing-sources="JSON_Test.pde"></canvas>
      </body>
  </html>
and this pde file with a function called GetWebData
1. float PanelTemp;
  float PoolTemp;
  int ControllerMode;
  int SetTempInc;
  int PanelCriticalTemp;
  long CumulativePumpRuntime;
  int PumpsOnOff;
  String StatusText;
  
  void setup()
  {
          size(320, 460);
          smooth();
  }
  
  void draw()
  {
  
          text(PanelTemp + ", " + PoolTemp + ", " + ControllerMode + ", " + SetTempInc + ", " + PanelCriticalTemp + ", " + CumulativePumpRuntime + ", " + PumpsOnOff + ", " + StatusText,40,50);
  }
  
  void GetWebData(float field1, float field2, int field3, int field4, int field5, long field6, int field7, String status)
  
  {
          PanelTemp = field1;
          PoolTemp = field2;
          ControllerMode = field3;
          SetTempInc = field4;
          PanelCriticalTemp =field5;
          CumulativePumpRuntime = field6;
          PumpsOnOff= field7;
          StatusText = status;
  }
And all I am trying to do is to pass this string 10.0,11.0,1,2,3,1234567,6,"This is a test" into the pde file so it will print on the screen!

Can I bugger get this to work. The problem is in the fact there are absolutely no bog basic idiot proof tutorials on how to do this. even pomax's jumps around and doesnt provide zip files with the working code for you to hack at

Please can someone help

Any help with the Javascript needed to grab JSON would be fantastic!!

[3 Replies]
- 27-Jun-2013 02:20 AM
- Forum: Processing with Other Languages
Hi guys,

Totally frustrated with the learning curve. What I want to do is pretty simple.

I want to grab this feed

http://api.thingspeak.com/channels/5384/feed/last.json?status=true

and get the data into this simple test sketch which i will run in processing.js
1. float PanelTemp;
  float PoolTemp;
  int ControllerMode;
  int SetTempInc;
  int PanelCriticalTemp;
  long CumulativePumpRuntime;
  int PumpsOnOff;
  String StatusText;
  
  void setup()
  {
  }
  
  void draw()
  {
          GetWebData(10.0,11.0,1,2,3,1234567,6,"This is a test");
           println(PanelTemp + ", " + PoolTemp + ", " + ControllerMode + ", " + SetTempInc + ", " + PanelCriticalTemp + ", " + CumulativePumpRuntime + ", " + PumpsOnOff + ", " + StatusText);
  
  }
  void GetWebData(float field1, float field2, int field3, int field4, int field5, long field6, int field7, String status)
  
  {
          PanelTemp = field1;
          PoolTemp = field2;
          ControllerMode = field3;
          SetTempInc = field4;
          PanelCriticalTemp =field5;
          CumulativePumpRuntime = Long.valueOf(field6);
          PumpsOnOff= field7;
          StatusText = status;
  }
I can't use any libraries as its going to be javascript and I dont understand enough about javascript to properly format the code.

I have been playing around with formatting the data based on a local CSV file version. I would prefer to grab the CSV from the web server but it seems I can't do that with loadStrings() as it only works for a local file (Or file on the same domain).

It looks like I am being forced to use JSON as that seems to be the only method to get data from a remote web server but the learning curve seems horrendously steep. I can't even make head nor tail of POMAX's guide and I have looked all over the web and can't find anything simpler. They all assume more knowledge of javascript than I have and none of them have a working zip file containing all the code and a sample JSON file to play with.

Seems I have to create some javascript code to pass the object to the processing js pde. Im really surprised that there arent more working examples out there

Can anyone help with the javascript code to take the feed above and put it into my sketch. Once i have a working example I will understand far more what I am doing

loadstrings() from processing.js will is work with Thingspeak crossdomain.xml

[2 Replies]
- 26-Jun-2013 08:03 AM
- Forum: Processing with Other Languages
Hi,

I have no idea about these things. I notice that thingspeak gives a link to their crossdomain.xml file

I understand this instructs the browser that its ok to load files from their domain.

I plan to let my processing.js sketch load strings like this

loadstrings("api.thingspeak.com/blah blah blah")

But will it work.

Do I need to do anything special with the http://api.thingspeak.com/crossdomain.xml link they provide?

HTTP Error code 502 crashes sketch when using loadstrings("http//api.thingspeak.com etc etc

[4 Replies]
- 25-Jun-2013 07:35 AM
- Forum: Programming Questions
Happens usually after about an hour and 12 minutes.

I have no idea how to trap it. Any help would be greatly appeciated

How to deal with lost serial connection to arduino

[0 Replies]
- 24-Jun-2013 11:12 AM
- Forum: Integration and Hardware
Hi,

I have a sketch which takes serial data from the arduino parses it and sends it to thingspeak.

The trouble is for some reason, if the arduino is unplugged and i lost the serial connection, when its replugged in it doesnt pick back up again

Its an arduino uno by the way

Im looking for some neat way to say. If the serial connection is lost, close the current port and create a new one. any ideas?

Newbie with Out of memory when using client.write()

[1 Reply]
- 06-Jun-2013 12:08 PM
- Forum: Core Library Questions
Hello.

I hope someone can show me the error of my ways. It's a simple problem. I have written a sketch which takes input from the Arduino and sends it to thingspeak. I am making a post using a /GET command via client.write.

The program runs for a few hours then give out of memory. It starts off using around 25Mb, the gradually increased until I get an out of memory error

I am certain I haven't done anything silly like loading images in the draw loop.

It seems my problem is caused by creating a lot of new instances of the myClient object. Initially I had declared it in the setup routine and whilst I thought this would work fine I found that it would run once and then give a

                        java.net.SocketException: Software caused connection abort: socket write error

So I moved it to a function called void UpdateThingSpeak() and called it from the main loop. The code is all below

Now I get the problem where I am out of memory after a few hours. I have tried everything I can think of. Issuing a

                    myClient.stop();
                      myClient=null;
                      myClient = new Client(this, Server,80);

In the hope that if the old client was stopped and set to null the System.gc() would release the memory.

Please could someone help. I'm sure they will tell me I am doing something very stupid
As It doesnt seem to let me add all the code I have just included the bit with the problem

P.S Its just the bit which creates the new client in the UpdateThingSpeak() function, unless someone can spot something else obvious

Many many thanks
1. void UpdateThingSpeak()                                                        // Formats the output and sends it as a GET request to the ThingSpeak servers
  {
          url = ("GET /update?key="+APIKey+"&field1="+PanelTemp+"&field2="+PoolTemp+"&field3="+ControllerMode+"&field4="+SetTempInc+"&field5="+PanelCriticalTemp+"&field6="+CumulativePumpRuntime+"&field7="+PumpsOnOff+"&status="+StatusText+"\n");
  
          if (myClient!=null)
          {
                  myClient.write(url);
  //                myClient.stop();
  //                myClient=null;                                                         // Destroy the object to allow System.gc() to release the memory
                  myClient = new Client(this, Server,80);                                // Create a new Client connection to the ThingSpeak Server
          }
  }

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