how to update the value of a edit text in GUI ?

Hi all,

im trying to control an LED with Matlab GUI and serial port. I have already some functions and everything work when i put the code in the workspace. the Problem is with GUI: GUI takes the frequence 'f' and the desired voltage 'v' from the user and those will be the arguments of my control function. here is the code and when i run it, it works but when the user change the frequence or the voltage, there is no update, it still working with the old configurations.

[Locations of interest have been marked HERE]

delete(instrfind({'Port'},{'COM4'}))
clear s;
global s;
s=serial('COM4');
set(s,'BaudRate',115200);
fopen(s)

function turn_on_button_Callback(hObject, eventdata, handles)

global s;

f=get(handles.frequenz_ablesen,'String');    %HERE

if (str2num(f)>5000)

     fprintf('Error: The frequenz must not be greater than 5000\n');

else

v=get(handles.spannung_ablesen,'String');     %HERE

fprintf(s,'%s\r','SDRVC A-01 0 0 str2num(f) str2num(v)')    %HERE

fprintf(s,'%s\r','SDRVP A-01 1')

fprintf(s,'%s\r','SDRVW A-01 1')

end

function frequenz_ablesen_Callback(hObject, eventdata, handles)

function frequenz_ablesen_CreateFcn(hObject, eventdata, handles)

if ispc && isequal(get(hObject,'BackgroundColor'), 

get(0,'defaultUicontrolBackgroundColor'))

      set(hObject,'BackgroundColor','white');
  end

function spannung_ablesen_Callback(hObject, eventdata, handles)

if ispc && isequal(get(hObject,'BackgroundColor'), 

get(0,'defaultUicontrolBackgroundColor'))

      set(hObject,'BackgroundColor','white');

end

i hope that someone can help me

thanks

Answer 1

[Walter Roberson]

Your line

fprintf(s,'%s\r','SDRVC A-01 0 0 str2num(f) str2num(v)')    %HERE

is going to send literally

SDRVC A-01 0 0 str2num(f) str2num(v)

Try

fprintf(s, 'SDRVC A-01 0 0 %s %s\r', f, v)

Answer 2

[derecho]

Hi

thanks for the ansewer:) the cmd to send is SDRVC A-01 0 0 str2num(f) str2num(v), thats why i wonder why its not working. i tried yours but it still not working, ERROR the cmd is not defined. But when i put manually the frequency and the volt value in the GUI code, it work fine

[Walter Roberson]

When I say that it literally sends

SDRVC A-01 0 0 str2num(f) str2num(v)

I mean that after the '0 0 ', it would send 's' then 't' then 'r' then '2' and so on. Your command

fprintf(s,'%s\r','SDRVC A-01 0 0 str2num(f) str2num(v)')    %HERE

does not evaluate the str2num, it puts in 's' 't' 'r' etc as strings.

If it would be more natural to you, you could use

    fprintf(s, '%s\r', ['SDRVC A-01 0 0 ', str2num(f), ' ', str2num(v)] )    %HERE