can someone give me the matlab function code for setting the time for a certain system to turn on?

setting the time to automatically turn on the light, for example, the light will turn on from 7am to 12 am, and 1pm to 5pm every monday, wednesday and friday. then 8am to 11am, and 12nn to 4pm every tuesday, thursday and saturday, thanks

[Jan]

You forgot to mention, that this is a Simulink problem.

Answer 1

[Image Analyst]

You can put

theDateTime = datestr(now)

in a loop and then parse the string for whatever conditions you want. You might also set up a time to get that string if you want to do it with that approach.

[evrenl]

I am not so familiar with the use of strings, can you give the full matlab code for that? Monday,Wednesday,and Friday from 7am to 12 nn, 1pm to 5pm. Then Tuesday, Thusday, Saturday, and Sunday, 8am to 11am, 12nn to 4pm. Thanks

[Image Analyst]

I think that would be a perfect learning opportunity for you. You got to learn sometime because you can't go around asking other people to write code for you, so what better time to learn than with this simple example?

[evrenl]

thanks for the advice, but can you atleast tell me a brief description of what the function will turn out. thanks

Answer 2

[Walter Roberson]

No, in order to give you that code we would need documentation on the mechanisms your device requires to turn it on or off.

Perhaps you should make your requirement clearer. Do you need a function that, when run, tells you whether the light should be on or off at the current time? (If so, how would you test it for other times?)

[evrenl]

yes, i need a function that for a specific span of time, the light should be turned on and off, just like what is stated there in the description of the question. or you can simply use a display that will show or output 1 or 0 when a certain time is achieved. i would be very grateful if you can tell me what would be the best way to do it or if you can code for me, thanks.

[Walter Roberson]

You mean like the program should wait until the next change, then should output the new state, and then wait again? How would you test that?

[evrenl]

using real time simulations.it will be based on the time of the pc

[Walter Roberson]

function onoff = checktime(candidate_time)
   onoff = 0;
   dn = weekday(candidate_time);
   dv = datevec(candidate_time);
   h = dv(4);
   if ismember(dn, [2, 4, 6])    %monday weds friday
     if ismember(h, [7:11, 13:17])
       onoff = 1;
     end
   elseif ismember(dn, [1, 3, 5, 6])  %sunday tuesday thursday saturday
     if ismember(h, [8:10, 12:15])
        onoff = 1;
     end
   end
 end

[evrenl]

thanks for the code, i've tried it using matlab function block, but there are series of errors when i've simulated it. and what should be the input of this block.

[Walter Roberson]

For the input:

http://www.mathworks.com/matlabcentral/answers/30479-how-to-get-system-date-and-time-into-simulink#answer_38947

This will be a 1 x 1 double.

I see that weekday and datevec are not supported for code generation, so you will need to coder.extrinsic those.

If your purpose is to create a Simulink model for deployment to a device, remember that a lot of devices have no idea what date or time it is. But you could create C code that fetched the time (if supported by your target); see http://stackoverflow.com/questions/5141960/get-the-current-time-in-c . Some of the examples there show how to break the clock time into fields. None of the available fields are day of the week, so you might need to calculate that (day of the year plus the day number of January 1 of the year, minus 1, convert that to a day of the week by using mod 7 but you need to decide whether to deal with a day #0 of the week or a day #7 of the week.)

[Walter Roberson]

One way to call C code from MATLAB Function blocks is to use coder.ceval

[evrenl]

can you do a code intrinsic code for me for the function to work? and also, the input you have given me do not have the number of days, will it affect the operation of the function?

[Walter Roberson]

Is this to be deployed to hardware, or is this for emulation on a system that has Simulink installed?

[evrenl]

this is just for a simulink model of automatic room lighting and air conditioning system, this would not be deployed into hardware. thanks

[evrenl]

will it be too much if you can make what you have coded for me to work?

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/30479-how-to-get-system-date-and-time-into-simulink#comment_65423

except replace "eml" with "coder", as in

coder.extrinsic("now")

[evrenl]

 h = dv(4);

an error occurs in this line, what must be done?

[evrenl]

 h = dv(4);

it says that "Subscripting into an mxArray is not supported". i didn't quite understand this part of the code. can you explain to me how this line works?

[Walter Roberson]

What is the error?

[evrenl]

it seems that Matlab does not recognized that code. here is what it says: Function 'MATLAB Function1' (#23.186.191), line 7, column 8: "dv(4)"

Answer 3

[Jan]

This seems a job for a timer:

function SetTimer(Date, Func, Args)
% Date as DATESTR: "2016-Mar-01 12:23:15'
% Func: Function handle to the function, which is called at teh specified time
% Arguments for the called function as {1 x N} cell
Delay  = round((datenum(Date) - now) * 86400);  % in seconds
TimerH = timer('ExecutionMode', 'singleShot', ...
   'StartDelay', Delay, ...
   'TimerFcn', cat(2, {Func}, Args));
start(TimerH);
end

Now the main program and a function for switching:

function Main
Time1 = datestr(now + 10 / 86400, 0);  % In 10 seconds
Time2 = datestr(now + 12 / 86400, 0)   % In 12 seconds

SetTimer(Time1, @TheSwitcher, {'on'});
SetTimer(Time2, @TheSwitcher, {'off'});

end

function TheSwitcher(TimerH, EventData, Arg)
% Here the code appears to perform the wanted operation.
disp(Arg);
end

[evrenl]

i didn't quite understand how to connect the main program to the timer program, can it be applied to a matlab function block :)

[Walter Roberson]

If you mean "MATLAB Function Block", previously known as Embedded MATLAB Function Block, then you would need to use coder.extrinsic to talk to the MATLAB timer facilities, and you would be limited to Normal mode, as timer objects are not supported for code generation for deployment to targets.

If you are talking about an Interpreted MATLAB Block, then you can use any MATLAB code.

[evrenl]

is Interpreted MATLAB Block a block in simulink?

[Walter Roberson]

http://www.mathworks.com/help/simulink/slref/interpretedmatlabfunction.html

[evrenl]

what is the input of this function?

[Walter Roberson]

The input to which function? Jan documented the inputs to his SetTimer() function.

If you are talking about an Interpreted MATLAB Block, then you would need to send it a vector of values. The vector could represent the information about when to turn on a device. However, you start to run into limitations in Simulink in that Simulink does not have a signal type for strings or characters, so those would need to be encoded.

How were you thinking of allowing the timing to be configured?

[evrenl]

is the above function created by Jan is connected with the code you have created on your answer?

[Calvin Page]

hey. evrenl..have you solved your problem about your time scheduling.we might have the same problem :)..i might be searching for about 4 weeks just to get this topic. :( can i have some of your data that you have gathered about the time scheduler..ill be happy to :) thank you in advance :) God bless..

[Calvin Page]

and by the way can i also see your Gui that you have made :) just to have some ideas.. thanks..