Trying to use Timer in GUI. While attempting in following code it is showing error.
function main_OpeningFcn(hObject, eventdata, handles, varargin)
handles.output = hObject;
handles.timer = timer(...
'ExecutionMode', 'fixedRate', ... % Run timer repeatedly
'Period', 1, ... % Initial period is 1 sec.
'TimerFcn', {#send_Callback,hObject});
guidata(hObject, handles);
function send_Callback(hObject, eventdata, handles)
comma = get(handles.Tx_send, 'String');%Tx_send is a text field
TxText = char(comma);
sf = rc4e2(TxText,key);%rc4e2 is an encryption
key = TxText;
DBC = char(sf);
disp(DBC);
fwrite(handles.serConn, DBC);%serConn is COM port
The error: Error while evaluating TimerFcn for timer 'timer-1'. Attempt to reference field of non-structure array.
Try changing your timerFcn to {'send_Callback',handles}.
In your version (as written in the original question), you have to write
'TimerFcn', {#send_Callback,handles});
The reason MATLAB is showing this error is because when it calls the Callback function, it automatically passes the timer handle as first argument and an empty event structure as second argument. The argument you provide by using the cell array is the third one. This means, your send_Callback is called with the argument list handles.timer,event,hObject (in this case, hObject is the window handle).
Then in the Callback function, you try to access handles.Tx_send, but since handles is the third argument and you provided just the window handle as the third argument, MATLAB will try to access handles.output.Tx_send, which does not exist.
Passing handles as described above should solve your problem because then the callback will have access to the handles object.
Related
I'm trying to make a timer that counts down from 20 to 0 (seconds) in GUIDE. In the meantime the user will perform a simple action (clicking a radio button in a group button) and at the end of that 20 seconds a message will appear (depending on which button the user clicked).
I looked around but it seems that there isn't a timer object for GUIDE (why don't they make one since it's so useful??). However I tried to make one and below there's the result, it doesn't work.
I initialised setappdata in MyGUI_OpeningFcn:
% Initialize setappdata
timeout = 20;
setappdata(handles.figure1,'timeout', timeout);
Next_calculation is radio button and timerBox is a static text.
function Next_calculation_Callback(hObject, eventdata, handles)
[..]
timeout = getappdata(handles.figure1,'timeout');
t = timer('Period', 1.0,... % 1 second
'StartFcn', set(handles.timerBox,'String',num2str(timeout)), ...
'ExecutionMode', 'fixedRate', ... % Starts immediately after the timer callback function is added to the MATLAB execution queue
'TasksToExecute', timeout, ... % Indicates the number of times the timer object is to execute the TimerFcn callback
'TimerFcn', #my_timer ... % callback to function
);
start(t)
Once the timer begins, it calls TimerFcn that calls my_timer. I should pass a handle to my_timer, but I don't know exactly how.
function my_timer(hObject, eventdata)
% I think I'm supposed to pass (hObject, eventdata) to my_timer
% handles should be getting the current figure from hObject
handles = guidata( ancestor(hObject, 'figure1') );
timeout = getappdata(handles.figure1,'timeout');
t_left = timeout - 1.0;
% show the updated time
set(handles.timerBox,'String',num2str(t_left));
% update 'timeout'
setappdata(handles.figure1,'timeout',t_left)
You need to use a custom anonymous function for the TimerFcn to pass the necessary data to your timer callback
set(t, 'TimerFcn', #(s,e)my_timer(hObject, handles))
You can then define your my_timer callback as
function my_timer(hObject, handles)
% Do stuff with handles
end
Suppose vec_A, vec_B, vec_c are some matrices with random data. I want to write data to text file for every 5 min, My code as follows:
function samplegui_OpeningFcn(hObject, ~, handles, varargin)
handles.timer = timer(...
'ExecutionMode', 'fixedRate', ... % Run timer repeatedly
'Period', 300, ... % Initial period.
'TimerFcn', {#open,hObject}); % Specify callback
handles.output = hObject;
handles.vec_A=[];
handles.vec_B=[];
handles.vec_C=[];
guidata(hObject, handles);
function open_Callback(hObject, eventdata, handles) % push button 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);
start(handles.timer); % saving the data
dlmwrite('My_sample1.txt',handles.vec_A);
dlmwrite('My_sample2.txt',handles.vec_B);
dlmwrite('My_sample3.txt',handles.vec_C);
stop(handles.timer);
end
guidata(hObject, handles);
While running my code, following error occurs:
Error while evaluating TimerFcn for timer 'timer-6'
Too many input arguments.
How to execute timer in this case to write data successfully for every five minutes or suggest any other way to do it.
You have defined your TimerFcn to be {#open, hObject} but you don't have a function named open. Instead, it is trying to call the built-in open with three input arguments (the timer object, an event object, and hObject) and this is producing the error because open only accepts one input argument.
That being said, it's not clear at all how the code that you have provided will accomplish anything close to what you want. Something like this may work better.
function samplegui_OpeningFcn(hObject, ~, handles, varargin)
handles.timer = timer(...
'ExecutionMode', 'fixedRate', ... % Run timer repeatedly
'Period', 300, ... % Initial period.
'TimerFcn', #(s,e)write_data()); % Specify callback
handles.output = hObject;
handles.vec_A=[];
handles.vec_B=[];
handles.vec_C=[];
guidata(hObject, handles);
start(handles.timer);
%// Now update your data in a loop
cnt = 0;
while true
%// Getting data from Serial Port
get_lines = fgets(handles.se)
if ~isempty(LINES)
cnt = cnt + 1;
if strfind(LINES, 'T')
handles.vec_A = [handles.vec_A; [timet newword]];
plot(handles.vec_A(:,1), handles.vec_A(:,2:end),'r');
drawnow
end
end
end
function write_data()
%// Write it to file
dlmwrite('My_sample1.txt',handles.vec_A);
dlmwrite('My_sample2.txt',handles.vec_B);
dlmwrite('My_sample3.txt',handles.vec_C);
end
end
I created an interface which automatically reads in data through the serial port, hence the reason I implemented the BytesAvailableFcn Callback
handles.fileID.BytesAvailableFcnMode = 'terminator';
handles.fileID.BytesAvailableFcn = {#streamData_fastTrak, handles};
The data that is read is displayed in a table chosen by the user (through use of radio buttons in the GUI). When an option is chosen a callback occurs to save the selected radio button to a variable which is saved in the handles struct. I have followed the program step for step and I am sure this callback does occur and that the variable is saved. However when the serial callback occurs the handles struct still has the old option value.
Here is the serial callback code:
function handles = streamData_fastTrak(hObject, eventdata, handles)
handles.num = handles.num + 1;
%receive data through serial
line = transpose(fscanf(handles.fileID, ' %f ' ));
table_data = get(handles.uitable1, 'data');
table_data_style = get(handles.uitable4, 'data');
display(handles.butt_state);
display(handles.num);
if(fix(line(1)) == 1 && strcmp(handles.butt_state, 'style_button'))
table_data_style(handles.select_Indices(1), 2:(length(line)+1)) = num2cell(line);
set(handles.uitable4, 'data', table_data_style);
display(handles.select_Indices);
elseif(fix(line(1)) > 1 && strcmp(handles.butt_state, 'stat_button'))
table_data(line(1)-1, 1:length(line)) = num2cell(line);
set(handles.uitable1, 'data', table_data);
if(line(1) == countStates(handles))
streamSensor_1_2_3(hObject, handles);
handles.time_step = handles.time_step + 1;
end
end
And the radio button callback:
function uipanel2_SelectionChangeFcn(hObject, eventdata, handles)
handles.butt_state = get(get(handles.uipanel2,'SelectedObject'), 'tag');
display(handles.butt_state);
guidata(hObject, handles);
The way I see it there are 2 ways to approach the problem:
The first way (I don't recommend this as much as the second one) is to pass the data you want updates to a string control and have it read back by your serial port function.
The other way that i recommend is to include a dummy button with a call back that calls
handles.fileID.BytesAvailableFcn = {#streamData_fastTrak, handles};
Again - this will update the new "handles" data to the callback function
For example
Assuming a dummy push button with tag PB1
function handles = streamData_fastTrak(hObject, eventdata, handles)
%% do stuff here
%% update handles data
PB1_Callback (handles.PB1,event,dat)
guidata(handles.PB1,handles) %% function ends
%% dummy button callback function%%
function PB1_Callback(hObject,event,handles)
handles.fileID.BytesAvailableFcn = {#streamData_fastTrak, handles};
guidata(hObject,handles) %% dummy button function ends
You can make the dummy button invisible by making the background color of the button same as that of the UI.
When you first declare your callback function for the ByteAvailableFcn in the line:
handles.fileID.BytesAvailableFcn = {#streamData_fastTrak, handles};
Matlab assign the function handle to the event and also pass the handles stucture at this point of time. This is now frozen into the private workspace of the callback. If you change the handles structure later on in your code (as you do when you try to attach the variable handles.butt_state), the callback doesn't know it, it still use the handles structure that was passed when you declared the callback.
There are several ways of getting this value correctly but I'll give 2 of them:
1) get the value from the radio button when needed
in your streamData_fastTrak callback function, query the button state directly from the uicontrol (instead of checking for a saved value)
handles.butt_state = get(get(handles.uipanel2,'SelectedObject'), 'tag');
This way you are sure to get the latest state of the radio button.
2) Store value in appdata
Every time the button state is changed, store the value somewhere, but you still have to query this value when your callback want to execute. A good place to save values are in the appdata (accessed using setappdata and getappdata).
So in your button callback:
function uipanel2_SelectionChangeFcn(hObject, eventdata, handles)
butt_state = get(get(handles.uipanel2,'SelectedObject'), 'tag');
setappdata(handles.uipanel2, 'butt_state' , butt_state );
display(butt_state);
And in your streamData_fastTrak callback:
function handles = streamData_fastTrak(hObject, eventdata, handles)
butt_state = getappdata(handles.uipanel2, 'butt_state' );
%// and the rest of your code ...
As already asked more or less in this question: https://stackoverflow.com/questions/14397729/working-with-multiple-guis-in-matlab
I want to have the output parameers and wait for a gui to finish.
I now use waitfor, but the output is always only a single handle
handle = uiConfigureCalibration('uiMain', handles.figure1);
waitfor(handle);
display(handle);
The output function of uiConfigureCalibration however passes several parameters:
function varargout = uiConfigureCalibration_OutputFcn(hObject, eventdata, handles)
varargout{1} = handles.output;
if isfieldRecursive(handles, 'handles.files.calibration')
varargout{2} = handles.files.calibration;
varargout{3} = handles.calibration;
end
Any chance to get these parameters somehow in the calling function ?
You would have to do
[output,FilesCalibration,Calibration] = uiConfigureCalibration('uiMain', handles.figure1);
to grab additional outputs - you are only asking for one output in your function call, so you always get one output. However, this will fail if you output single parameter.
Since number of outputs is variable, I think it is better to return structure containing all outputs:
function output = uiConfigureCalibration_OutputFcn(hObject, eventdata, handles)
output.output = handles.output;
if isfieldRecursive(handles, 'handles.files.calibration')
output.files.calibration = handles.files.calibration;
output.calibration = handles.calibration;
end
Now function essentially returns a subset of handles structure, containing 1 or 3 fields depending on the structure of handles
How to get the value of a uicomponent slider on Matlab when a key is pressed?
I'm using this in the GUI code:
% --- Executes just before teste is made visible.
function teste_OpeningFcn(hObject, eventdata, handles, varargin)
% Choose default command line output for teste
handles.output = hObject;
handles.slid=uicomponent('style','slider',0,9,5,'position',[10 30 200 50]);
set(handles.slid, 'KeyPressedCallback','handles.slid.value');
% Update handles structure
guidata(hObject, handles)
The slider works correctly, but when I press a key, this returns the error "Undefined variable "handles" or class "handles.slid.value".
How to solve?
You can connect a callback to the desired event and get the value there from the src parameter
handles.slid=uicomponent('style','slider',0,9,5,'position',[10 30 200 50]);
set(handles.slid, 'KeyPressedCallback','sliderCallback');
function sliderCallback(src,evt)
display(['slider state ' num2str(get(src, 'Value'))]);
end
If the sliderCallback function is not accessible globally, you can instead set it through function pointer:
set(handles.slid, 'KeyPressedCallback',#sliderCallback);