How do I use a timer to run 2 functions at different speeds?

Hi guys,

I'm quite new at matlab, so I'm probably using a way to difficult solution for my problem.

I'm trying to have my code do two things at the same time. Currently it is increasing 1 value 1 till 400 and another till 2000. And I want to do this in one second. So value2 has to increase faster than value1.

However value 2 never reaches 2000. And the code is not fast enough.

Is it feasible to do what I want to do? And so yes, what am I doing wrong?

Thank in advance

The code I'm using for this is:

clc;
clear;

previousMillis1 = clock;
previousMillis2 =clock;

Rate1 = 400;
interval1 = 1/Rate1;

Rate2 = 2000;
interval2 = 1/Rate2;

value1 = 0;
value2 = 0;

while value2<Rate2
  currentMillis = clock;

    if ((currentMillis(6)- previousMillis1(6)) >= interval1)
       value1 = value1 + 1
       previousMillis1(6) = currentMillis(6);
    end 
    
    if ((currentMillis(6) - previousMillis2(6)) >= interval2)
       value2 = value2 + 1
       previousMillis2(6) = currentMillis(6);
    end  
end

[Ganesh Regoti]

Hi Floortje,

I have a question. Do you specifically want that task to be done on MATLAB or using Simulink , StateFlow is also fine?

[Floortje Lycklama à Nijeholt]

I actually haven't use StateFlow before, but I think it would be fine as well.

In the parts where the values increase I actually want to read some values using labView. Do you think that would be possible with StateFlow as well?

Answer 1

[Ganesh Regoti]

Hi Floortje,

According to my understanding on problem, you want to execute certain statements at particular time step and State Flow works perfect for such cases because when you execute in code format there might be some latency between execution and I/O operation which might give you wrong results.

Simulink/StateFlow executes the blocks/states at the step-time given explicitly and also implicitly. You can design your own states that would serve your purpose.

You can set fixed time step explicitly for the execution of states which would be GCD of two intervals in your case.

Model Configuration Parameters -> Solver Selection (Fixed-step) -> Solver details -> Fixed Step Size

Refer the following links for more understanding

https://www.mathworks.com/help/stateflow/index.html?s_tid=CRUX_lftnav(Documentation)

https://www.mathworks.com/help/stateflow/examples.html (Examples)

[Floortje Lycklama à Nijeholt]

Thanks!

I'll go check it :D