rtwdemo_roll represents an autopilot control system for an
aircraft. You prepare
rtwdemo_roll for embedded code generation by using
Embedded Coder® Quick Start, which chooses fundamental code generation settings based on your
goals and application.
Save a copy of the model to a writable location on the search MATLAB path.
If the C Code tab is not already open, in the Apps gallery, under Code Generation, click Embedded Coder.
On the C Code tab, click Quick Start.
Advance through the steps of the Quick Start tool. Each step asks questions about the code that you want to generate. For this tutorial, use the defaults that are already selected. The tool validates your selections against the model and presents the parameter changes required to generate code.
In the Generate Code step, apply the proposed changes and
generate code from
rtwdemo_roll by clicking
Click Finish, then return to the C Code tab. From this tab you can configure code generation customizations, and then check the results in the Code view next to the model.
The generated code appears in two primary files:
rtwdemo_roll.h. In your MATLAB® current folder, the
rtwdemo_roll_ert_rtw folder contains
these primary files.
In your current folder, the code generator creates the
This folder contains the
rtwtypes.h file, which defines standard data types
that the generated code uses by default. In general, this sibling folder contains generated
files that can or must be shared between multiple models.
The code that you generate from a model includes entry-point functions, which you call from your application code. For a rate-based model, these functions include an initialization function, an execution function, and, optionally, terminate and reset functions. The functions exchange data with your application code through a data interface that you control.
Open the Code Mappings editor by clicking Code Mappings below the model diagram. On the Functions tab, you can see the individual entry-point functions that the code generator produces. You call these generated functions from external code or from a version of a generated main function that you modify. For the base-rate step function of a rate-based model and for step functions for export function models, you can customize the function name and arguments.
Review the list of entry-point functions that the code generator produces for the model.
Use this view to selectively specify for each function a function customization template (code
definition) and name. For this tutorial, the code generator uses default (shipped) settings
for the customization template and entry-point function names. The code generator names the
rtwdemo_roll_initialize and the execution (step)
rtwdemo_roll_step. Both entry-point functions have a
void-void interface (they pass no arguments).
The functions gain access to data through shared data structures. Examples of such data
include system-level input and output that the functions exchange with application
To see these entry-point functions in the generated code:
On the right side of the Simulink® Editor window, in the Code view pane, locate the search bar.
In the search bar, type
rtwdemo_roll_step. To find each instance
of the step function name across the generated code files, click the search
Use the arrows on the right to step through each instance, including the step
function definition in
rtwdemo_roll.c and the declaration in
rtwdemo_roll.h. You can also see the number of search hits in each
file from the file menu in the upper left corner.
Repeat these search steps to locate the initialize function,
rtwdemo_roll_initialize in the generated code.
Next, configure the data interface for code generation and review the generated code.