Text doesn't change in guide while i can see it change in the commande window

Hello, im receiving data from bluetooth, and i want to show it in a guide text using a timer to show it every x seconds, so i wrote the following program, im not getting any error, and i can see values change in the commande window, but nothing changes in the guide. any idea?

function pushbutton4_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global tmr
stop(tmr)
set(findobj('Tag','text5'),'String', ' ');
set(findobj('Tag','alT'),'String',' ');


% --- Executes on button press in pushbutton5.
function pushbutton5_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton5 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global tmr
tmr = timer('ExecutionMode', 'FixedRate', ...
            'Period', 5 , ...
            'TimerFcn', {@timerCallback});
start(tmr);


function timerCallback(hObj, eventdata)

global temp Data Temperatura n a
temp = characteristic(Data, "000F1809-0000-0000-0100-000100001809", "000F1006-0000-0000-0100-000100001809");
temperatura = 13 / 255 *read(temp)+32;

if temperatura < 36.3
    a = "Hypotermia";
elseif temperatura > 38.3 && temperatura < 40.3
    a = "Pyrexia";
elseif temperatura > 40.3  
    a = "Hypertermia";
else
    a = " ";
end 

temperatura= round(temperatura, 1);
t = string(temperatura);

set(findobj('Tag','text5'),'String',t);
set(findobj('Tag','alT'),'String',a);

Answer 1

[Jan]

It is not the cause of your problems, but global variables are a shot in your knee. Avoid them consequently. Instead of searching for a specific tag, you can provide the handle to the callback.

function pushbutton4_Callback(hObject, eventdata, handles)
stop(handles.tmr);
delete(handls.tmr);
handles.text5.String = ' ';
handles.alT.String   = ' ';
guidata(hObject, handles);

function pushbutton5_Callback(hObject, eventdata, handles)
handles.tmr = timer('ExecutionMode', 'FixedRate', ...
            'Period', 5 , ...
            'TimerFcn', {@timerCallback, handles});
start(tmr);
guidata(hObject, handles);

function timerCallback(hObj, eventdata, handles)
temp = characteristic(Data, "000F1809-0000-0000-0100-000100001809", "000F1006-0000-0000-0100-000100001809");
temperatura = 13 / 255 *read(temp)+32;

if temperatura < 36.3
    a = "Hypotermia";
elseif temperatura > 38.3 && temperatura < 40.3
    a = "Pyrexia";
elseif temperatura > 40.3  
    a = "Hypertermia";
else
    a = " ";
end 

temperatura= round(temperatura, 1);
t = string(temperatura);

handles.text5.String = t;
handles.alT.String   = a;
drawnow;   % <-- use this to update the figure

I assume, the final drawnow solves your problem already.

[0Luk]

Thank you!