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FiniteStateMachineExample.c
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FiniteStateMachineExample.c
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//////////////////////////////////////////////////////////////////////////////////////////////
//
// Shell example for Implementing a State Machine
//
// State machines are a very common program architecture. This program provides a basic
// 'shell' or 'template' as a starting point for implementation.
//
// Among other things, it illustrates two useful concepts for a state machine:
//
// 1. Use an "enum" definition to keep track of your differnt states. As opposed to using
// numeric values. It's far easier to add/change states to the machine without having
// to go back and change the program -- the 'case' values will auto adjust as you
// add/subtract states.
//
// 2. Ensure there is a "default" clause in the 'switch on state' block so that you can
// trap usage of invalid values for the state machine.
//
//////////////////////////////////////////////////////////////////////////////////////////////
typedef enum
{
stateInitialization,
stateForward,
stateReverse,
stateShuttingDown
} TStates;
TStates nCurrState;
task main()
{
//
// One-time startup code
//
nCurrState = stateInitialization;
//
// COntinuous loop for state machine
//
while (true)
{
switch (nCurrState)
{
case stateInitialization:
/* Insert program specific code here */
break;
case stateForward:
/* Insert program specific code here */
break;
case stateReverse:
/* Insert program specific code here */
break;
case stateShuttingDown:
/* Insert program specific code here */
break;
default:
// Should never get here. Play warning message and restart
PlaySound(soundLowBuzz);
nCurrState = stateInitialization;
break;
}
}
}