Receive value in Matlab GUI

Hello I'm working with Matlab GUI using GUIDE about show status from arduino(Ex:degree,current) and I have .m file program in Matlab to calculate and read variables when I press 'Start' button. I want program to receive realtime variables. Is there any way to do to make it work? I already try to get variables but It just give me only first time value. Here is my example of my .m file

function [B1, B2, B3, B4] = LogDataB(arduino)
mode=2;

fopen(arduino);

while mode
    fprintf(arduino,'%s',1);

      if(mode>=1)
             B1=fscanf(arduino,'%d');
             B2=fscanf(arduino,'%d');%Bx
             B3=fscanf(arduino,'%d');%By
             B4=fscanf(arduino,'%d');%Bz

      end

      mode=mode-1;
  end

fclose(arduino);

Any idea please.

Thank you

Math

Answer 1

[Geoff Hayes]

Thanadech - presumably the function LogDataB is called from the callback of your start button. Is this the case? Note that your while loop will only ever execute twice since your mode is initialized to two. As well, the results obtained for mode equal to two are overwritten for the case when mode is one. Is this intentional?

If you want this function to be called repeatedly once the start button is pressed, you may need to use a timer. See an example at http://www.mathworks.com/matlabcentral/answers/178682-collecting-a-variable-every-two-minutes which you should be able to adapt for your needs. In your case, the timer callback would call your above function.

[Thanadech Wunapeera]

Thank you. Yes, Geoff. B1,B2,B3,B4 is called from the callback of start button to show value and loop execute twice is ok. I'm intent to do that because mode equal to one is nothing.

Would you please help me a little bit? I don't understand in TimerCallback function in your example. If I have a static textbox, How do I change in TimerCallback to show in textbox? It's ok to overwritten the old value in the box. I tried many times to change them but It's still error or nothing happen. I really new to Matlab.

Thank you so much

Math

[Thanadech Wunapeera]

Hahaha, Ok. I got it. Thank you so much for your help Geoff.