Question

Your supervisor has assigned you to build a finite state machine (FSM) in C code to control the operation of a gas pump. You determine that the required states are: . idle, payment card verifying payment approved, payment denied, nozzle removed, waiting for grade selection, e pumping. finalizing transaction (i.e. the nozzle has been returned) . emergency (someone drove off before removing the nozzle, fire detected, etc. The first thing you decide to do is to create a custom C data type to represent the states. Using the typedef keyword, create your custom data type in the answer space

Answer 1

Following is the custom type created using the keyword typedef in C. If the combination of these states and triggered event match, the corresponding event handler is called..

//Different states of Gas Pump using typedef

typedef enum
{
Idle_State,
Payment_Card_Verifying_State,
Payment_Approved,
Payment_Denied,
Nozzle_Removed,
Waiting_Grade_Selection,
Pumping,
Finalizing_Transaction,
Emergency
}sysState;

//Prototype of event handlers
sysState IdleStateHandler(void)
{
return Idle_State;
}
sysState PaymentCardVerifyingStateHandler(void)
{
return Payment_Card_Verifying_State;
}

sysState PaymentApprovedHandler(void)
{
return Payment_Approved;
}

sysState PaymentDeniedHandler(void)
{
return Payment_Denied;
}

sysState NozzleRemovedHandler(void)
{
return Nozzle_Removed;
}

sysState WaitingGradeSelectionHandler(void)
{
return Waiting_Grade_Selection;
}
sysState PumpingHandler(void)
{
return Pumping;
}
sysState FinalizingTransactionHandler(void)
{
return Finalizing_Transaction;
}
sysState EmergencyHandler(void)
{
return Emergency;
}