/* Signal module for Railroad HandCar arcade game */

/* Set DDR port T byte to input, M byte to output */
/* Set port AD I/O bits and initialize PWM module */

InitializePorts
  Accepts nothing, returns nothing

  Set port T to input and port M to output
  Set port T values all low

  Initialize port AD to all digital output + 1 analog input
  Set the 1 analog input port value high

  Initialize the PWM ports (T0-T2) 


/* Pulse enable (port M0) to signal jumping motor */
				
PulseEnable
  Accepts nothing, returns nothing

  Set port M bit 0 high
  Wait for 100 msec
  Set port M bit 0 low

/* Set start indicator LED ON (State != 0) or OFF */

void ReadyLED(char State) {
  Accepts a char, returns nothing

  If the char is high (non-zero)
    Set port M bit 4 high
  Else
    Set port M bit 4 low

/* Check whether penny inserted; LO means present */

CheckForPenny
  Accepts nothing, returns a char (boolean)

  Return whether port T bit 7 is low

/* Sound the game chime for OnTime amount of time */

SoundHorn
  Accepts an unsigned int, returns nothing

  Set port AD bit 1 low
  Wait the indicated duration
  Set port AD bit 1 high

/* Beep (sound game chime) at indicated frequency */

Beep
  Accepts a char, returns nothing

  For the number of times indicated
    Sound the game horn for constant time
    Wait for an equivalent constant time
  
/* Check whether 'start' button has been pressed  */

CheckStartButton
  Accepts nothing, returns a char (boolean)

  Return whether port T bit 3 is low

/* Get the current handle position (range 0-1023) */

HandlePosition
  Accepts nothing, returns a short

  Return the analog value at port AD pin 0
}

/* Set port M5 HI or LO to direct puppet handpump */

Pump
  Accepts a char, returns nothing

  If the indicated direction is up
    Set port M bit 5 high
  Else
    Set port M bit 5 low

/* Set PWM scroll speed on port T0 & adjust range */

SetScrollSpeed
  Accepts and unsigned int, returns nothing

  If the speed indicated is non-zero
    Set PWM duty on port T bit 0 to speed / 2 + 25

/* Place villain within servo range from position */

PlaceVillain
  Accepts an unsigned char, returns nothing

  Set PWM duty on port T bit 1 to the indicated position

/* Check whether the hand car is over an obstacle */

AtObstacle
  Accepts nothing, returns a char (boolean)

  Return whether port T bit 6 is low

/* Set port M1 HI or LO to direct motor direction */

void Jump(char Direction) {  
  Accepts a char, returns nothing

  If the indicated direction is up
    Set port M bit 1 high
  Else
    Set port M bit 1 low

  Pulse the enable line on port M  
} 

/* Check whether a jump or landing event occurred */

GetJumpEvent
  Accepts nothing, returns a char (state)

  If port T bit 4 or bit 5 is high 
    Set the jump state to down
  Else
    Set the jump state to up
  
  If the jump state is the same as last time
    Return NO_EVENT

  Set the old state to the jump state
  
  If the jump state is up
    return JUMPED
  Else
    return LANDED

/* Set port M2 LO to vibrate handle for collision */

void VibrateHandle(char Signal) {
  Accepts a char, returns nothing

  If the indicated signal is on
    Set port M bit 2 high
  Else
    Set port M bit 2 low

/* Dispense SWAG for the specified length of time */

DispenseSWAG
  Accepts nothing, returns nothing

  Set port M bit 3 high
  Wait a constant amount of time
  Set port M bit 3 low