How to import data from a microprocessor

I am making an interface through app designer but I do not know how to receive the data stored in a microprocessor using a tcpip object.

[Jonathan Chin]

Can you be more specific in your issue? Are you having networking issues or not sure how to set up a tcp object in matlab?

[Guillermo Cid Espinosa]

I am not sure how to set up a tcp object in Matlab. I have done the code but when I run the program the vectors do not receive the data so they are empty.

function read(app)

app.DataReceived_ch=fread(app.t_waveforms);

% Two 8-bit values are read for each 16-bit integer

        i=1;
        j=1;
         while i<length(app.DataReceived_ch)
          app.B(j) = 2^8*app.DataReceived_ch(i+1)+app.DataReceived_ch(i);

% The int numbers greater than (2 ^ 16) -1 are converted to negative

        if app.B(j) > 32768
           app.B(j)=app.B(j)-65536;
        end
          i=i+2;
          j=j+1;  
         end

% The data are distributed in 4 vectors

      app.H1=length(app.B)-4;
      app.B=0.1*app.B;
      app.B1(1 : app.H1/4)=app.B(1 : 0.25*app.H1);    
      app.z1=app.B1;
      app.z1
      app.B2(1 : app.H1/4)=app.B(1+(0.25*app.H1) : 0.5*app.H1);   
      app.z2=app.B2;
      app.B3(1 : app.H1/4)=app.B(1+(0.5*app.H1) : 0.75*app.H1);    
      app.z3=app.B3;
      app.B4(1 : app.H1/4)=appp.B(1+(0.75*app.H1) : app.H1);
      app.z4=app.B4;

flushinput(app.t_waveforms);

pause(0.2);

end % function read

function startupFcn(app)

            app.tip=app.IPField.Value;
            app.t_waveforms = tcpip(app.tip, 80);
            app.t_buttons = tcpip(app.tip, 80);
            app.t_waveforms.BytesAvailableFcn = @read;
            app.t_waveforms.BytesAvailableFcnCount = app.buffer+8; 
            app.t_waveforms.BytesAvailableFcnMode = 'byte';
            set(app.t_waveforms, 'InputBufferSize', app.buffer+8);
end

function StartButton (app,event)

                    app.tip=app.IPField.Value;                                               
                    app.t_waveforms= tcpip('192.168.1.100', 80);                   
                    fopen(app.t_waveforms);
                    echotcpip('off');
                    fprintf(app.t_waveforms,'GET /Interface_waveforms');
                    pause(0.01);
end

[Jonathan Chin]

Can you communicate with the device with out using the ByteAvailableFcn to read back but instead use fread? If so then the device might not be sending a terminator or enough bytes

[Guillermo Cid Espinosa]

I have read the data directly using fread without using ByteAvailableFcn and the data has been stored correctly but now I have another problem and this is that in the graph only the first data are represented and these are not updated even if new data is received.

function StartButton(app) If app.Start.Value==1

        set(app.t_waveforms, 'InputBufferSize', app.buffer+8);
        app.tip=app.IPField.Value;                                              
        app.t_waveforms= tcpip('192.168.1.100', 80);                   
        fopen(app.t_waveforms);
        echotcpip('off');
        fprintf(app.t_waveforms,'GET /Interface_waveforms');
        pause(0.01);           
        app.DataReceived_ch=fread(app.t_waveforms);

% Two 8-bit values are read for each 16-bit integer

        i=1;
        j=1;
         while i<length(app.DataReceived_ch)
          app.B(j) = 2^8*app.DataReceived_ch(i+1)+app.DataReceived_ch(i);

% The int numbers greater than (2 ^ 16) -1 are converted to negative

        if app.B(j) > 32768
           app.B(j)=app.B(j)-65536;
        end
          i=i+2;
          j=j+1;  
         end

% The data are distributed in 4 vectors

      app.H1=length(app.B)-4;
      app.B=0.1*app.B;
      app.B1(1 : app.H1/4)=app.B(1 : 0.25*app.H1);    
      app.z1=app.B1;
      app.z1
      app.B2(1 : app.H1/4)=app.B(1+(0.25*app.H1) : 0.5*app.H1);   
      app.z2=app.B2;
      app.B3(1 : app.H1/4)=app.B(1+(0.5*app.H1) : 0.75*app.H1);    
      app.z3=app.B3;
      app.B4(1 : app.H1/4)=app.B(1+(0.75*app.H1) : app.H1);
      app.z4=app.B4;

flushinput(app.t_waveforms);

pause(0.2);

if strcmp(app.Switch.Value, 'Stop')

fclose(app.t_waveforms); fopen(app.t_waveforms);

fprintf(app.t_waveforms,'GET /Interface_waveforms');

end end

function GraphButton(app)

if app.Graph.Value==1

xlim(app.Grafica1,[1 app.n*length(app.Q)]); plot(app.Grafica1,app.z2,'b','linewidth',1.25);

end

Thanks for your help

[Jonathan Chin]

fprintf(app.t_waveforms,'GET /Interface_waveforms');

What I would try is to manually send this command, then do a fread to get the data back and send it again. If this works it could be an issue with how your app is sending command and getting the data.

Do you only hit the StartButton once? if so I think you need to have some way of sending the above command

[Guillermo Cid Espinosa]

Yes, I only hit the button once but if I disconnect and connect the button again, the new data are represented so I think the problem is that the function is not run cyclically but I do not know why.

[Jonathan Chin]

try adding a button that runs calls by itself

fprintf(app.t_waveforms,'GET /Interface_waveforms');

I believe you need to call this every time you want data then put a debug point there to see if you can get some data

[Guillermo Cid Espinosa]

Yes, that is the problem. I do not know how to execute that command cyclically.