How can I create a specific stopwatch

I've just started using MATLAB and was wondering if I could make a stopwatch timer which displays tasks after a specific time. Multiple tasks ie.

At 40 seconds - Display " Task_1" text

At 60 seconds - Display " Task_2" text

At 95 seconds - Display " Task_3" text

And a way to reset the timer, including all tasks. The tasks should be noticeable when displayed as well.

Layout of the timer should be in hh:mm:ss

[Adam Danz]

What do you mean 'layout of the timer should be in hh mm ss'? Do you mean you want a GUI that shows the current time in the timer?

Are you running the timer from the command window or within a code or do you already have a GUI that will run the timer?

[Rik]

The short answer is yes. You can look into the timer function/object. To help you in a more concrete way, we'll need some more information, like the questions that Adam asked, as well as what form the tasks are. Are they available as a function to run?

[Ahsen Abid]

Well it would be convenient to have implement the code into GUI, but at the moment, I managed to find a code somewhere on the site which executes a command after a specific time. So the current code I'm using is

t = timer('TimerFcn', 'stat=false; disp(''Task_1'')',... 
                 'StartDelay',4);
start(t)

stat=true;
dispTime = 1;
while(stat==true)
disp(dispTime)
pause(1)
dispTime = dispTime + 1;
end
t = timer('TimerFcn', 'stat=false; disp(''Task_2'')',... 
                 'StartDelay',15);
start(t)

stat=true;
while(stat==true)
disp(dispTime)
pause(1)
dispTime = dispTime + 1;
end
t = timer('TimerFcn', 'stat=false; disp(''Task_3'')',... 
                 'StartDelay',5);
start(t)

stat=true;
while(stat==true)
disp(dispTime)
pause(1)
dispTime = dispTime + 1;
end

This is pretty much what I was looking for but further question:

- Can I implement this code into a GUI? ie. having this on a digital display clock and on the side displaying "Task_n" when it's time?

Sorry if my questions seem bad

And to answer Adam's query, I'm currently running scripts

[Adam Danz]

You could add a count-down clock to the GUI I shared below.

Answer 1

[Adam Danz]

I coded up a demo for you. The m file is attached but I've also included the code below so I can walk you through it. I suggest you download the m file so you can run it and play around with it.

This section sets up a quick and dirty GUI that allows the user to

1. Select a task type (each task time will have its own message)
2. Enter the delay period (second)
3. Control the timer (start, stop, reset).

% Set up GUI
h.fig = figure('name', mfilename); 
options = {'task 1', 'task 2', 'task 3'};
h.list1 = uicontrol('style', 'listbox', 'units', 'normalize', 'position', [.25 .30 .45 .51], 'string', options);
h.text1 = uicontrol('style', 'text', 'units', 'normalize', 'position', [.25 .83 .45 .06], 'string', 'Select task message', 'fontsize', 12);
h.edit1 = uicontrol('style', 'edit', 'units', 'normalized', 'position', [.80 .72 .12 .06], 'string', 40); 
h.text1 = uicontrol('style', 'text', 'units', 'normalize', 'position', [.70 .81 .3 .05], 'string', 'Delay (seconds)', 'fontsize', 12);
h.button1 = uicontrol('style', 'pushbutton', 'units', 'normalize', 'position', [.20 .03 .10 .10], 'string', 'Start');
h.button2 = uicontrol('style', 'pushbutton', 'units', 'normalize', 'position', [.45 .03 .10 .10], 'string', 'Stop');
h.button3 = uicontrol('style', 'pushbutton', 'units', 'normalize', 'position', [.70 .03 .10 .10], 'string', 'Reset');
set(h.button1, 'callback', {@controlTimerCallback, 'start', h})
set(h.button2, 'callback', {@controlTimerCallback, 'stop',  h})
set(h.button3, 'callback', {@controlTimerCallback, 'reset', h})

This callback function is executed by all of the GUI button and it either creates a new timer, stops an existing timer, or resets an existing timer.

function controlTimerCallback(hObj, ~, command, handles)
% Receives command from GUI to control timer(s)
% get time delay (seconds)
delayTime = str2double(handles.edit1.String); 
% get the message type
msgType = handles.list1.String{handles.list1.Value};
% Name of timer for this task 
timerName = sprintf('announcementTimer %s', msgType); 
% Perform command
switch command
    case 'start'
        % Create new timer.  Ideally, you'd want to check if one exists under this task name alread.
        % Create timer object; name it after the task type.
        t = timer('name', timerName);
        t.ExecutionMode = 'singleShot';
        t.StartDelay = delayTime;
        t.TimerFcn = {@dispTimerMsg msgType};
        % Start timer; it will stop after 1 cycle.
        start(t)

      case 'stop'
          % Search for a timer with task name and stop it.
          % The search query needs to match the naming convensions in the 'start' case. 
          t = timerfind('name', timerName); 
          stop(t)

      case 'reset'
          % To reset, we're just going to close and restart the timer. 
          controlTimerCallback(hObj, [], 'stop', handles); 
          controlTimerCallback(hObj, [], 'start', handles);

      otherwise
          error('Unknown command.')
  end

Finally, this callback function is executed by the timer and displays a message box after the timer has reached its delay period (if it hasn't been stopped).

function dispTimerMsg(~, ~, msgType)
% This function is called by the timer object 'tObj' and displays a message
% chosed by 'msgType'.
switch msgType
    case 'task 1'
        msg = 'Task 1 complete';
        icon = 'none';
    case 'task 2'
        msg = 'Task 2 complete';
        icon = 'none';
    case 'task 3' 
        msg = 'Task 3 complete';
        icon = 'none';
    otherwise
        msg = 'Error: Message type unknown';
        icon = 'error';
end
% here the mode is set to 'replace' such that future msgboxs will replace ones already in the screen.
msgbox(msg, 'Timer', icon, 'replace')

The message boxes will overwrite each other if >1 appears but that can be changed by removing 'replace' in the msgbox() call.

[Adam Danz]

Note that matlab warns again using their timer class for real-time applications that require greater precision.

https://www.mathworks.com/help/matlab/ref/timer-class.html