' Name        : WAKEX2.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : 28/40-pin PIC types compatible with LAB-X2 board
' Hardware    : LAB-X2 Experimenter Board
' Oscillator  : 4MHz external crystal
' Keywords    : NAP
' Description : PICBASIC PRO program to demonstrate wake on interrupt.
'

' You should DISABLE THE WATCHDOG TIMER when programming the
' PICmicro device.

' The program outputs the condition of the switches on the
' LEDs, then immediately goes into power-down mode.  When
' the condition on any switch changes, the RB port change
' interrupt occurs, waking the part.

' Since the global interrupt enable bit is not set, no 
' jump to the interrupt vector occurs.  Program execution 
' is resumed, the LEDs are updated, and the part goes back
' to sleep.

' To further reduce the power consumption, all unused
' hardware peripherals should be disabled.  The PORTB
' pullups should be replaced with external resistors, and
' the internal pullups disabled.

' Define LOADER_USED to allow use of the boot loader.
' This will not affect normal program operation.
Define LOADER_USED 1

' Define the pins that are connected to pushbuttons.
' The switches must be connected to PORTB, pins 4,5,6,
' or 7 in order to use the RB port change interrupt.
sw1 VAR PORTB.4
sw2 VAR PORTB.5
sw3 VAR PORTB.6

' Define the pins that are connected to LEDs
led1 VAR PORTB.0
led2 VAR PORTB.1
led3 VAR PORTB.2

   INTCON.3 = 1      ' Enable the RB port change interrupt
   OPTION_REG = $7f  ' Enable PORTB pull-ups
   TRISB = %11111000 ' Set PORTB.0-2 (LEDs) to output, 3-7 to input

' main program begins here
main: 
   PORTB = 0         ' Turn off all LEDs

   ' Check any button pressed to toggle on LED
   IF sw1 = 0 Then led1 = 1
   IF sw2 = 0 Then led2 = 1
   IF sw3 = 0 Then led3 = 1
        
   INTCON.0 = 0    ' Clear the RB port change flag bit
   NAP 7           ' Go to sleep.  When the watchdog is
                   ' disabled, NAP won't wake up until
                   ' an interrupt occurs.

   GoTo main       ' Do it again upon waking

   End