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How to stop timer function at a specified time?

Hello..
I have used a timer function to capture image files continuously at a fixed rate automatically, at a specified time. I used startat function to do this and it's working, however, my problem is that, I can't stop it at a specified time I want. Instead I use pause. However, once I paused the program, the whole program halts and it never execute the next functions.
Can anyone help me?
Here's some part of my code:
dstart={'07:30' '07:32' '07:34' '12:00' '13:30' '15:00' '18:00' '19:30'};
dfinish={'07:31' '07:33' '07:35' '13:25' '07:31' '16:25' '09:01' '20:55'};
%here i used the captureimage function to capture image using imaq toolbox..
t1=timer('TimerFcn', 'captureimage', 'ExecutionMode', 'FixedRate');
tp1=timer('TimerFcn', 'pause'); %I can't stop the timer fcn that's why i use pause
%the capture starts exactly at 07:30AM continuously with 7second interval
startat(t1, dstart(1,1));
%here, the program pauses when it is exactly 07:31AM
startat(tp1, dfinish(1,1));
How can i stop the timer function without using pause, because instead of pausing the timer function, the whole program pauses.
I will greatly appreciate your help.
Thank you.

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3 Answers

Answer by Brett Shoelson on 4 Feb 2011
 Accepted Answer

Kent, Why not build into the callback a comparison of the current time (help NOW) with the desired stop time? Then, if current time >= desiredStopTime, then issue a STOP command. Cheers, Brett

  1 Comment

thanks for the idea..appreciate it.. c:

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Answer by Jan
on 4 Feb 2011

% Create times as DATENUM vector:
TimerData.start = floor(now) + datenum( ...
{'07:30' '07:32' '07:34' '12:00' '13:30' '15:00' '18:00' '19:30'});
TimerData.finish = floor(now) + datenum( ...
{'07:31' '07:33' '07:35' '13:25' '07:31' '16:25' '09:01' '20:55'});
TimerData.index = 1;
T = timer('TimerFcn', @myTimerFcn, ...
'ExecutionMode', 'FixedRate', 'Period', 7.0, ...
'UserData', TimerData);
startat(T, TimerData.start(1));
% ------ Timer function:
function myTimerFcn(TimerH, EventData)
TimerData = get(TimerH, 'UserData');
% Stop time reached?
if now >= TimerData.finish(TimerData.index)
stop(TimerH);
TimerData.index = TimerData.index + 1;
% Last time reached?
if TimerData.index > length(TimderData.start)
delete(TimerH); % Cleanup
else % Restart the timer at the next start time:
set(TimerH, 'UserData', TimerData); % EDITED2
startat(TimerH, TimerData.start(TimerData.index));
end
return; % EDITED
end
% Perform the action - insert your code here:
capturimage
% ------ End: Timer function
Good luck!

  4 Comments

Show 1 older comment
Jan, will I still use startat function to execute the timer function?
Jan, I've tried it, but still, the capture does not stop at 07:31AM (where the capture starts at 07:30AM)..instead, the program keeps on capturing (from 7:30AM onwards).. What do you think is the problem?
Can StartFcn or StopFcn be useful?
Thanks.
Jan
on 4 Feb 2011
@Kent: StartFcn and StopFcn are executed, when the timer is started or stopped, but they do not trigger the starting or stopping.
Yes, you need to start the timer by STARTAT. I insert it in the code.
I've inserted an RETURN in the code to improve it. Please try it again.

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Answer by Kent Cabarle on 5 Feb 2011

%Actually, here is my main code..
function kxlsforum
% Assignation
[num dset]=xlsread('class.xls'); % 9x7 skedule
day = datestr(now, 'dddd'); % exact date
t0=timer('TimerFcn', 'kaptur1camtemplate', 'ExecutionMode', 'SingleShot');
dk={'1' '2' '3' '4' '5' '6' '7' '8'};
% Assign and check day and time
for n=2:7 % check Mon - Sat
k=dset(1,n); % disp Mon-Sat etc, compare with actual day
c = strcmp(k,day);
if c == 1
fdate=datestr(now, 'mmddyyyy');
mkdir(fdate);
disp('Today is '); disp(day);
disp('Capturing an image template..');
start(t0); % capture 1 image as template
disp('Image template captured')
for p=1:8
de(1,p)=isempty(dset{p+1,n}); % 0 - occupied
switch de(1,p) % 1 - vacant
case 0
mkdir(fdate, dk{1,p});
end
end
disp(de);
break % break FOR loop
end
end
f=find(~de); % find the 1st class time & last class time capture
mini=min(f);
maxi=max(f);
TimerData.start = floor(now) + datenum({'07:30' '07:34' '07:37' ... '12:00' '13:30' '15:00' '18:00' '19:30'});
TimerData.finish = floor(now) + datenum({'07:31' '07:35' '07:38'... '13:25' '07:31' '16:25' '09:01' '20:55'});
TimerData.index = 1;
T = timer('TimerFcn', @myTimerFcn, 'ExecutionMode','FixedRate',... 'Period', 7.0,'UserData', TimerData);
start(T) % i used this is execute the timer
Here is the timer function (separate file)
% ------ Timer function: function myTimerFcn(TimerH, EventData) TimerData = get(TimerH, 'UserData'); %Stop time reached?
TimerData.start = floor(now) + datenum({'07:30' '07:34' '07:37' '12:00' '13:30' '15:00' '18:00' '19:30'}); TimerData.finish = floor(now) + datenum({'07:31' '07:35' '07:38' '13:25' '07:31' '16:25' '09:01' '20:55'}); TimerData.index = 1;
if now >= TimerData.finish(TimerData.index)
stop(TimerH);
TimerData.index = TimerData.index + 1;
% Last time reached?
if TimerData.index > length(TimderData.start)
delete(TimerH); % Cleanup
else % Restart the timer at the next start time:
startat(TimerH, TimerData.start(TimerData.index));
end
return;
end
% Perform the action - insert your code here:
kaptur1
end
% ------ End: Timer function
In the main function, i used the start(T) to execute the timer, instead of startat.. (i used a separate function which is kaptur1camtemplate to capture a single image which will be the basis for image processing..[not included here])
and in the timer function, i just did what you advised me to do..(i used the kaptur1 function for image capturing here..) however, the capturing did not start capturing at 7.30AM, and still not stopping at its specified time, for for this instance 7.31AM..
Can't figure it out.. What do you think?
Thanks for the help..a lot..

  12 Comments

sir walter, i found this error when i tested what you told me..
??? Error while evaluating TimerFcn for timer 'timer-5'
Undefined variable "TimderData" or class "TimderData.start".
the capture started at exactly 7:30:00AM, after 7:30:59AM, the capture stops and the error went out..what do you think?
sir jan simon, thank you for the help.. sir walter, thanks also..
If that is the error message you are getting, then you have a typo in your code, 'TimderData' instead of 'TimerData'
@Walt. It worked. It starts capturing at 7.30AM and stops at 7.31AM. Then starts capturing again at 7.32AM, and so on.. Great. Thank you..
@Jan: Thanks also. Thanks for the kindness and wit. Thanks to both of you. Appreciate it. ^^

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