How to run callback functions independently guide matlab - multithreading

Question

MATLAB GUI with two push buttons exist. Each push button begins an execution of an infinite loop of reading a serial data from Com-Port(different). When I press a push button the while loop reading Serial port, but when I press the next push button, the port1 stops and then the port2 starts reading, and when I stops the port2, the port1 resuming.So here my question is, how all callback functions with while loops can work independently and simultaneously..
function samplegui_OpeningFcn(hObject, ~, handles, varargin)
handles.output = hObject;
handles.vec_A=[];
handles.vec_B=[];
handles.vec_C=[];
handles.vec_A_1=[];
handles.vec_B_1=[];
handles.vec_C_1=[];
guidata(hObject, handles);
function open_Callback(hObject, eventdata, handles) % push button1 to receive serial data.
cnt=0;
while 1
% Getting data from Serial Port
get_lines=fgets(handles.se) % getting data from serial port
if~isempty(get_lines)
cnt=cnt+1;
if strfind(get_lines,'T') %Parsing data
handles.vec_A=[handles.vec_A;[timet newword]];
plot(handles.vec_A(:,1),handles.vec_A(:,2:end),'r'); % plotting
% Same follows for parsing and plot vec_B and Vec_C
drawnow(); % to update the Plots
end
end
Pause(.05);
end
guidata(hObject, handles);
function open2_Callback(hObject, eventdata, handles) % push button2 to receive serial data.
cnt=0;
while 1
% Getting data from Serial Port
get_lines=fgets(handles.se2) % getting data from serial port2
if~isempty(get_lines)
cnt=cnt+1;
if strfind(get_lines,'T') % Parsing data
handles.vec_A_1=[handles.vec_A;[timet newword]];
plot(handles.vec_A_1(:,1),handles.vec_A_1(:,2:end),'r'); % plotting
% Same follows for parsing and plot vec_B and Vec_C
drawnow(); % to update the Plots
end
end
Pause(.05);
end
guidata(hObject, handles)

Answer 1

You cannot do this in MATLAB because it is only possible to execute one task at a time. The way around this would be to have a timer that listens to each serial port at a given interval and the push buttons start/stop this timer. You would not need a while loop with a pause in this case, you would just need a funciton that gets the data from a serial port once and call this function each time the timer fires.
%// Function called each time a timer is fired, gets data from specified serial port
function getData(hObject, handles, serialport)
get_lines = fgets(serialport);
if isempty(get_lines)
return
end
if strfind(get_lines,'T')
handles.vec_A = [handles.vec_A; [timet newword]];
plot(handles.vec_A(:,1),handles.vec_A(:,2:end),'r');
drawnow();
end
guidata(hObject, handles);
end
%// And for your button callbacks that will toggle the timers on/off
function open2_Callback(hObject, eventdata, handles)
if ~isfield(handles, 't2') || ~isvalid(handles.t2) || ~handles.t2.Running
%// Create a timer that checks the serial port twice a second
handles.t2 = timer('ExecutionMode', 'fixedRate', ...
'Period', 0.5, ...
'TimerFcn', #(s,e)getData(hObject, handles, handles.se2));
%// Start the timer
start(handles.t2);
else
%// Stop and destroy the timer
stop(handles.t2);
delete(handles.t2);
end
guidata(hObject, handles);
end
function open_Callback(hObject, eventdata, handles)
if ~isfield(handles, 't1') || ~isvalid(handles.t1) || ~handles.t1.Running
handles.t1 = timer('ExecutionMode', 'fixedRate', ...
'Period', 0.5, ...
'TimerFcn', #(s,e)getData(hObject, handles, handles.se1));
start(handles.t1);
else
stop(handles.t1);
delete(handles.t1);
end
guidata(hObject, handles);
end
Update
As mentioned by #Hoki in the comments, you could also set the byteAvailableFcn property of the serial connection which would automatically fire (somewhat assynchronously) when new data arrives. This would prevent you from having to periodically poll the serial port for new data.
function getData(serialport, hObject, handles)
get_lines = fgets(serialport);
if strfind(get_lines,'T')
handles.vec_A = [handles.vec_A; [timet newword]];
plot(handles.vec_A(:,1),handles.vec_A(:,2:end),'r');
drawnow();
end
guidata(hObject, handles);
end
set([handles.se2, handles.se1], 'BytesAvailableFcn', #(s,e)getData(s, hObject, handles);

Answer 2

function samplegui_OpeningFcn(hObject, ~, handles, varargin)
handles.output = hObject;
handles.vec_A=[];
handles.vec_B=[];
handles.vec_C=[];
handles.vec_A_1=[];
handles.vec_B_1=[];
handles.vec_C_1=[];
guidata(hObject, handles);
end
function getData_1(hObject, handles, serialport)
get_lines = fgets(handles.se_1);
if isempty(get_lines)
return;
end
if strfind(get_lines,'T')
handles.vec_A = [handles.vec_A; [timet newword]];
plot(handles.axes1,handles.vec_A(:,1),handles.vec_A(:,2:end),'r');
drawnow();
end
guidata(hObject, handles);
end
function getData_2(hObject, handles, serialport)
figure;
hold on;
ax(1)=subplot(3,1,1);
ax(2)=subplot(3,1,2);
ax(3)=subplot(3,1,3);
get_lines = fgets(serialport);
if isempty(get_lines)
return
end
if strfind(get_lines,'T')
handles.vec_A_1 = [handles.vec_A; [timet newword]];
plot(handles.vec_A_1(:,1),handles.vec_A_1(:,2:end),'r');
drawnow();
end
guidata(hObject, handles);
end
function open2_Callback(hObject, eventdata, handles)
if ~isfield(handles, 't2') || ~isvalid(handles.t2) || ~handles.t2.Running
%// Create a timer that checks the serial port twice a second
handles.t2 = timer('ExecutionMode', 'fixedRate', ...
'Period', 0.5, ...
'TimerFcn', #(s,e)getData_2(hObject, handles, handles.se2));
%// Start the timer
start(handles.t2);
else
%// Stop and destroy the timer
stop(handles.t2);
delete(handles.t2);
end
end
function open1_Callback(hObject, eventdata, handles)
if ~isfield(handles, 't1') || ~isvalid(handles.t1) || ~handles.t1.Running
%// Create a timer that checks the serial port twice a second
handles.t2 = timer('ExecutionMode', 'fixedRate', ...
'Period', 0.5, ...
'TimerFcn', #(s,e)getData_2(hObject, handles, handles.se2));
%// Start the timer
start(handles.t2);
else
%// Stop and destroy the timer
stop(handles.t2);
delete(handles.t2);
end
end
It is similar code while you given.. added while loop because It could not read data continously at the port.