.. sectnum::
    :start: 1

Usage
+++++++

Introductions
===============

    - The project consists of two main parts: an editor (CHSM) to draw state machines and a C library (CRF) that is able to drive the C code generated by the editor.

    - CHSM (editor) features:
        - Written in Python and Vanilla Javascript. (Tested with Python 3.7+ and Chromium on RPi4 and with Chrome and Firefox on Win10.)
        - The editor can generate C code from the drawings.
        - Application file format is Html. Can be opened without the editor in view-only mode with any browser.
        - Comments can be added to any string.
        - Comments are displayed as tooltips on mouse hover and added as actual C comments to the generated code.
        - Mostly follows the UML statecharts specification (event deferral is an exception).

    - The CRF (C Reactive Framework) design was heavily influenced by Miro Samek's excellent book: [Practical UML Statecharts in C/C++](http://www.state-machine.com/psicc2/). If you are not familiar with UML statechars then I recommend reading it. All the important concepts are explained very clearly in a first few chapters with easy to understand examples.

    - CRF features:
        - Run-to-completion (RTC) execution model
        - Written in C99. (Uses C11 atomics when available, if not, than the application must define two simple atomic functions.)
        - State transitions are precalculated at code generation to avoid the runtime cost of hierarchy discovery.
        - All states are represented by functions that process events with a switch statement.
        - Optional event pools that provide simple O(1) dynamic memory handling to releive modules from buffering.
        - Wait-free multi-producer single-consumer event queues for each state machines.
        - Events can be deferred and recalled.
        - Events can be safely generated and distributed by interrupts.
        - Optional event generators for "analog" int32 values and uint8_t bitfields.
        - Unit tests (using the Unity framework).

.. include:: ./installation.rst
.. include:: ./configuration.rst
.. include:: ./quickstart.rst