Button Debouncing Pseudocode

Pseudocode for ButtonModule FSM

Initialize Variables:

    CurrentState ← InitBState

    MyPriority ← Priority of this service

Function InitButtonModule(Priority):

    Set MyPriority to Priority

    Set CurrentState to InitBState

    Post ES_INIT event to this service

    If post is successful, return true

    Else, return false

Function PostButtonModule(Event):

    Post Event to the service queue with MyPriority

    Return success/failure of the operation

Function RunButtonModule(Event):

    Initialize ReturnEvent to ES_NO_EVENT (default state for no errors)

Switch(CurrentState):

        Case InitBState:

            If Event.Type is ES_INIT:

             Perform actions for initialization (if any)

             Transition to WaitForPress state

        Case WaitForPress:

            If Event.Type is BUTTON_DOWN:

             Start a timer for QUARTER_SEC duration

             Transition to PressDetected state

        Case PressDetected:

            If Event.Type is ES_TIMEOUT:

             Print "Press Detected" message

             Create new BUTTON_PRESSED event

             Post BUTTON_PRESSED event to RecInputService

             Transition back to WaitForPress state

        Default:

            Do nothing (no defined behavior for other states)

    Return ReturnEvent

Function QueryButtonModule():

    Return CurrentState