2837xd code generation - stateflow (1)

  stay Command Window Type in sf Can enter the , It can also be done through Simulink In the library StateFlow Sub library entry .

  StateFlow Finite state machine , Reuse matlab when , May feel ： A simple if Statements or ++ The operation needs to be built too complex . But the introduction of state machine can greatly reduce this situation .

  Entering the library function module, you can see that these three components are all state machine modules , Learn one by one ： First look at Chart modular .

1 Chart modular

Create a new Chart modular , After opening , Right click to enter Properties Set it up .

On the left side of the interface are some Chart Components used in ：

among , There is only mutual exclusion between each module （ Only one can execute ） And parallelism . There will be an execution order identifier in the upper right corner under the parallel relationship .

Which is divided into different levels by modules , The content under the same module is a level , If you need to set parallel and mutually exclusive relationships . Right click the blank space of the level to be set and select Decomposition Choose parallel and mutually exclusive relationships .

State Modules have some keywords that can be used to define the actions to be performed after entering these modules ：

Using the above knowledge, we can build a simple model , Take a look at the concept of flow chart .

First, build a simple model as shown in the above figure ,s Is the condition ,light It's the result of action . This is a process that simulates the switching of lights , turn on the light （s=1） Obviously, we need to give ,light The program needs to run to produce relevant results . Now enter Model Explorer The relevant settings are made in .

And then in Simulink Add relevant external modules , Give and display input and output .

The simulation results are as follows . change s Value , Can be changed accordingly light Value .

Transform the above process , Join the event .Open_switch(Close_Switch),b And in Model Exporer Defined in . Here, pay attention to the defined input port and demux The input should be consistent .

Then build a circuit ,Input3 It is used to activate the module . You can know at this time , It's not just about s=1, And need the rising edge （Open_switch The rising edge of the trigger of the event setting ） To trigger light=1. Similar to the rising edge in digital electricity, the corresponding signal can be locked .

In order to better write the process ,StateFlow The concept of connection node is introduced . Click on Parretn The following structures can be set .

You can also add conditions for your connection , When the mouse is placed on the line between the two connection points, the following marks will automatically appear , By default, when one node has multiple branches , Will give priority to the conditional branch .：

Pictured , Set up the following branches , Equate to C Code ：

if (x<0)
    y=abs(x);
else
    y=x;

stay Model Explorer Set relevant... In data Properties of , Given inputs and outputs . The given input here is 1Hz The sine wave of .

Now combine the state of the first switch lamp , If there are two states in the light on state （A、B） Represents different brightness . Then if we set the brightness for the first time , I certainly don't want to adjust the brightness again next time I turn on the light . Therefore, historical nodes are introduced here , That is, you can remember the last exit state , Even though A It's the default state . But the state at this time is determined by the state of the last exit ：

2 Model instance construction

2.1 Car status judgment

Build the following logic circuit for judging the car state , Be able to define the events generated above , Run , It can simulate gear shifting and start stop status monitoring :

After the completion of construction , You can click run directly , At this time, because there is no definition of related data and event An automatically defined interface will pop up , Make relevant modifications above to quickly add ：

Build peripheral circuits , Set the device runtime triggered by related events , Change the simulation duration to inf（ Infinite length ）, You can operate and observe experimental phenomena ：

2.2 Media playback status detection

  The media playing status can be observed through the flow chart , This example introduces historical nodes and state detection , Build as shown in the following figure chart, You can see in the power_on Some of the state transition flow charts in have no trigger conditions （ That means anything can trigger ）. for example , If now in USB state , If sent Open_CD(Open_Radio) After that, state transition can be triggered .

 

  Right click on the status to enter the attribute （Properties）, Modify the status output , Then you can observe the status at the output port （ Boolean variable output , by 1 It means in secondary state ）.

  The history node is added , Represents the next entry power_on When the module , It will directly enter the state of the last exit .

  Build the external circuit as shown in the figure below ：

2.3 2837xd Running water lamp online debugging

  First, build the following chart, here led1 and led2 It's all output . Direct connection GPIO Interface .

  The picture below is led1 and led2 Output waveform of , Identified in the figure 1.2.3.4 Corresponding to the execution process in the above figure . That's the cycle 3 After that , Out of the loop , Then go out and wait , Enter the next cycle . Here the test found , It will last one step in the state , Act at the node （3、4） It will take another step .[ The step size is set to 0.5s], Setting of relevant parameters , Please refer to the previous blog article .

  Program peripheral circuit diagram ：

  This is a debugging skill , The following figure SIMULATION and HARDWARE There is one in each RUN,SIMULINK Medium RUN Hardware can be disconnected , Run the software running results directly , That is, it can also be easily debugged chart Output module .HARDWARE Medium RUN Is to generate DSP Code burning into DSP And then run .