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From: Walter Roberson on 2 Jun 2010 18:06
Jorge Luis wrote:
> Walter Roberson <roberson(a)hushmail.com> wrote in message

>> Pass the figure number (or any object in the figure) as a parameter to
>> the callback when you create it.
>>
>> timer('TimerFcn', @(src,event) MyTimerCallback(src, event, gcf));

> Walter can you explain me the timer function.

Not unless you have a more specific question. It would take too long to write
everything I know or can deduce about timer functions and their usage and
interaction with other items.


> so i still define this as
> s1.BytesAvailableFcnCount = 40;
> s1.BytesAvailableFcnMode = 'byte';
> s1.BytesAvailableFcn=(a)mycallback;
> fopen(s1);
>
> handles.pushbutton2=s1;
> guidata(hObject, handles);

s1.BytesAvailableFcnCount = 40;
s1.BytesAvailableFcnMode = 'byte';
s1.BytesAvailableFcn = @(src, event) mycallback(src, event, hObject);
fopen(s1);

handles.pushbutton2 = s1; %why is a serial port object being stored in
%field named as a pushbutton ??

handles.inputdata = uint8([]);

guidata(hObject, handles);

while true
pause(0); %give callback a chance to read some data
if feof(s1); break; end %reached end of data
handles = guidata(hObject); %The callback might have changed the values
currentdata = handles.inputdata; %read pending data
handles.inputdata = uint8([]); %clear pending data
%now do something with the currentdata
...
end


function mycallback(src, event, FigureObject)
handles = guidata(FigureObject);
thisdata = fread(s1, s1.BytesAvailable);
handles.inputdata = [handles.inputdata thisdata];
guidata(FigureObject, handles);
end
From: Jorge Luis on 2 Jun 2010 20:35
Walter Roberson <roberson(a)hushmail.com> wrote in message <hu6kna$mcv$1(a)canopus.cc.umanitoba.ca>...
> Jorge Luis wrote:
> > Walter Roberson <roberson(a)hushmail.com> wrote in message
>
> >> Pass the figure number (or any object in the figure) as a parameter to
> >> the callback when you create it.
> >>
> >> timer('TimerFcn', @(src,event) MyTimerCallback(src, event, gcf));
>
> > Walter can you explain me the timer function.
>
> Not unless you have a more specific question. It would take too long to write
> everything I know or can deduce about timer functions and their usage and
> interaction with other items.
>
>
> > so i still define this as
> > s1.BytesAvailableFcnCount = 40;
> > s1.BytesAvailableFcnMode = 'byte';
> > s1.BytesAvailableFcn=(a)mycallback;
> > fopen(s1);
> >
> > handles.pushbutton2=s1;
> > guidata(hObject, handles);
>
> s1.BytesAvailableFcnCount = 40;
> s1.BytesAvailableFcnMode = 'byte';
> s1.BytesAvailableFcn = @(src, event) mycallback(src, event, hObject);
> fopen(s1);
>
> handles.pushbutton2 = s1; %why is a serial port object being stored in
> %field named as a pushbutton ??
>
> handles.inputdata = uint8([]);
>
> guidata(hObject, handles);
>
> while true
> pause(0); %give callback a chance to read some data
> if feof(s1); break; end %reached end of data
> handles = guidata(hObject); %The callback might have changed the values
> currentdata = handles.inputdata; %read pending data
> handles.inputdata = uint8([]); %clear pending data
> %now do something with the currentdata
> ...
> end
>
>
> function mycallback(src, event, FigureObject)
> handles = guidata(FigureObject);
> thisdata = fread(s1, s1.BytesAvailable);
> handles.inputdata = [handles.inputdata thisdata];
> guidata(FigureObject, handles);
> end

Walter,
It works, thank you very much.
I also wanted to know something. The interrupt is working, and i process the data everytime the interrupt is called, and i also want to put an image in my axes, when i dont have mycallback and do it in other callback, i only do imshow(); but know i do that in mycallback and it opens a new figure and appears the image, instead of putting it on the current axes.
From: Walter Roberson on 2 Jun 2010 23:57
Jorge Luis wrote:

> I also wanted to know something. The interrupt is working, and i process
> the data everytime the interrupt is called, and i also want to put an
> image in my axes, when i dont have mycallback and do it in other
> callback, i only do imshow(); but know i do that in mycallback and it
> opens a new figure and appears the image, instead of putting it on the
> current axes.

The current axes is subject to change at any mouse click, which makes it
difficult to communicate it correctly to the serial callback.

How about instead of the _current_ axes, you instead plot on a _known_
axes, the one associated with the plot? The difference is that if the
user goes off and clicks on something else, the graph would still go to
where you expect instead of to the place the user had clicked on.

If a _known_ axes is good, then create a field in the handles structure
to store the axes you want the plot to appear in, and call guidata() to
update the known handles structure. Then in whatever callback you want,
use guidata() to retrieve the handles (already done in mycallback to get
s1), and use the appropriate field of that as the axes handle.

However, I warn that if you wish to avoid losing data, you should avoid
doing any kind of complicated processing in the callback.

Recall too that the callback is not going to be generated every 40 bytes
of input exactly: it will be generated when there are 40 bytes of input,
but it might not be served until later, by which time there might be
more input bytes. The code structure I showed earlier, the loop with
pause() and so on, pulls off all data that has accumulated since the
data was last cleared, and would thus be a more appropriate place to
plot the data.
From: Ankit Desai on 3 Jun 2010 04:06
Walter Roberson <roberson(a)hushmail.com> wrote in message <wKFNn.25314$yx.5045(a)newsfe13.iad>...
> Jorge Luis wrote:
>
> > I also wanted to know something. The interrupt is working, and i process
> > the data everytime the interrupt is called, and i also want to put an
> > image in my axes, when i dont have mycallback and do it in other
> > callback, i only do imshow(); but know i do that in mycallback and it
> > opens a new figure and appears the image, instead of putting it on the
> > current axes.
>
> The current axes is subject to change at any mouse click, which makes it
> difficult to communicate it correctly to the serial callback.
>
> How about instead of the _current_ axes, you instead plot on a _known_
> axes, the one associated with the plot? The difference is that if the
> user goes off and clicks on something else, the graph would still go to
> where you expect instead of to the place the user had clicked on.
>
> If a _known_ axes is good, then create a field in the handles structure
> to store the axes you want the plot to appear in, and call guidata() to
> update the known handles structure. Then in whatever callback you want,
> use guidata() to retrieve the handles (already done in mycallback to get
> s1), and use the appropriate field of that as the axes handle.
>
> However, I warn that if you wish to avoid losing data, you should avoid
> doing any kind of complicated processing in the callback.
>
> Recall too that the callback is not going to be generated every 40 bytes
> of input exactly: it will be generated when there are 40 bytes of input,
> but it might not be served until later, by which time there might be
> more input bytes. The code structure I showed earlier, the loop with
> pause() and so on, pulls off all data that has accumulated since the
> data was last cleared, and would thus be a more appropriate place to
> plot the data.

Nicely summarized Walter.

To put what Walter suggested in code:

axesHandle = axes('PropertyName',propertyvalue,...);
plotHandle = plot(axesHandle,X1,Y1,LineSpec,'PropertyName',PropertyValue);
handles.axesHandle = axesHandle;
handles.plotHandle = plotHandle;
guidata(hObject,handles);

Hope this helps,

-Ankit
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