State Machine in C

This article demonstrates the state machine’s implementation in the C programming language.

Using a state machine to implement code is a valuable design strategy to resolve complex engineering issues. State machines take the overall design and split it into stages, referred to as states inside the state-machine jargon.

Every state is responsible for carrying out a particular function. On the other side, events are the stimuli that cause the state machine to change between states. It is also referred to as a transition.

When first written, most systems are straightforward and well-organized, but when new features are added, additional flags and variables are created to keep track of events’ history.

Then, if and else statements are added to test the ever-more-complex logical expressions created out of the many variables and flags.

In this regard, the state machines are of assistance. When utilized appropriately, state machines simplify the conditions tested at each branching point and make it easier to switch between various modes of program execution.

It turns out that the behaviour of most real-time systems can be divided into a relatively small number of non-overlapping chunks (states).

The event responses within each chunk depend only on the current event, and they no longer rely on the sequence of events that have occurred in the past.

The following is an example of code to build a state machine in C. This specific example generates two states switches back and forth between them ten times.

Then, it displays the index number and the state corresponding to that index.