LEDMap Module

This software module

1) Controls the 15LED Map which is driven by a decoder

2) Keeps track of the guards position as he approaches the computer room

Public Functions:

initLEDMap

Set output to decoder to zero (which corresponds to an output on the decoder that is NOT

connected to an LED)

Set wait times (for blinking and advancing the guard's position) to the calibrated values

Initialize internal state to LEDMap_OFF

LEDMapGuardAlerted

Update all the wait times to be a fraction of the calibrated values (this will speed up the

guard's progress and speed up the LED blinking)

checkLEDMapEvents

State machine using internal state

Case LEDMAP_OFF:

Do nothing

Case LEDMAP_RUNNING:

If enough time has passed

Update which LED is active

If guard has reached end of the map

Return LEDMAP_GUARD_ARRIVED

Else

Return LEDMAP_GUARD_RUNNING

Case LEDMap_GUARD_ARRIVED:

Do nothing

Regardless of what the internal state is, call updateOutputs() to handle blinking of LED

startLEDMap

Set internal state to LEDMAP_RUNNING

Turn on the first LED of the map

Set the blink state to be on initially

Update timing variables to the current time

Call updateOutputs

Module Functions:

updateOutputs

If enough time has passed for the current LED to be “blinked”

If current LED is currently on

Turn it off by setting decoder output to zero

Else

Turn it on by setting decoder output to the LED corresponding to the guard's position