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153 | // https://github.com/gbmhunter/FunctionPointerStateMachineExample
// https://github.com/misje/stateMachine
// http://misje.github.io/stateMachine/
#include <stdio.h>
#include <stdbool.h>
typedef enum
{
ST_IDLE,
ST_LED_ON,
ST_LED_OFF
} state_t;
typedef struct
{
state_t currState;
} stateMachine_t;
/// \brief All the possible events that can occur for this state machine.
/// \details Unlike states_t, these do not need to be kept in a special order.
typedef enum
{
EV_ANY,
EV_NONE,
EV_BUTTON_PUSHED,
EV_TIME_OUT,
} event_t;
typedef struct
{
const char *name;
void (*func)(void);
} stateFunctionRow_t;
void Led_Init()
{
printf("Led_Init() called.\r\n");
}
void Led_On()
{
printf("LED turned on.\r\n");
}
void Led_Off()
{
printf("LED turned off.\r\n");
}
void Led_Idle()
{
printf("LED in idle state.\r\n");
}
/// \brief Maps a state to it's state transition function, which should be called
/// when the state transitions into this state.
/// \warning This has to stay in sync with the state_t enum!
static stateFunctionRow_t stateFunctionA[] = {
// NAME // FUNC
{"ST_IDLE", &Led_Idle}, // ST_IDLE
{"ST_LED_ON", &Led_On}, // ST_LED_ON
{"ST_LED_OFF", &Led_Off}, // ST_LED_OFF
};
typedef struct
{
state_t currState;
event_t event;
state_t nextState;
} stateTransMatrixRow_t;
static stateTransMatrixRow_t stateTransMatrix[] = {
// CURR STATE // EVENT // NEXT STATE
{ST_IDLE, EV_BUTTON_PUSHED, ST_LED_ON},
{ST_LED_ON, EV_TIME_OUT, ST_LED_OFF},
{ST_LED_ON, EV_BUTTON_PUSHED, ST_IDLE},
{ST_LED_OFF, EV_TIME_OUT, ST_LED_ON},
{ST_LED_OFF, EV_BUTTON_PUSHED, ST_IDLE}};
void StateMachine_Init(stateMachine_t *stateMachine)
{
printf("Initialising state machine.\r\n");
stateMachine->currState = ST_IDLE;
}
// TIP
void StateMachine_RunIteration(stateMachine_t *stateMachine, event_t event)
{
// Iterate through the state transition matrix, checking if there is both a match with the current state
// and the event
for (int i = 0; i < sizeof(stateTransMatrix) / sizeof(stateTransMatrix[0]); i++)
{
if (stateTransMatrix[i].currState == stateMachine->currState)
{
if ((stateTransMatrix[i].event == event) || (stateTransMatrix[i].event == EV_ANY))
{
// Transition to the next state
stateMachine->currState = stateTransMatrix[i].nextState;
// Call the function associated with transition
(stateFunctionA[stateMachine->currState].func)();
break;
}
}
}
}
const char *StateMachine_GetStateName(state_t state)
{
return stateFunctionA[state].name;
}
int main()
{
printf("main() called.\r\n");
// Create new state machine object
stateMachine_t stateMachine;
StateMachine_Init(&stateMachine);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
// Push button to start flasher
printf("Button pushed.\r\n");
StateMachine_RunIteration(&stateMachine, EV_BUTTON_PUSHED);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
// Timeout
printf("Timeout.\r\n");
StateMachine_RunIteration(&stateMachine, EV_TIME_OUT);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
// Timeout
printf("Timeout.\r\n");
StateMachine_RunIteration(&stateMachine, EV_TIME_OUT);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
// Timeout
printf("Timeout.\r\n");
StateMachine_RunIteration(&stateMachine, EV_TIME_OUT);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
// Push button again to stop flasher
printf("Button pushed.\r\n");
StateMachine_RunIteration(&stateMachine, EV_BUTTON_PUSHED);
printf("State is now %s.\r\n", StateMachine_GetStateName(stateMachine.currState));
return 0;
}
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