' Name        : BUTX.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : 40-pin 16F877A, 18F452 or similar
' Hardware    : Lab-X1
' Oscillator  : 4MHz external crystal
' Keywords    : IF THEN
' Description : PICBASIC PRO program to show button presses
' on 4 LEDs with the LAB-X1.
' 

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

   OPTION_REG = $7f    ' Enable PORTB pull-ups
   TRISD = 0           ' Set PORTD (LEDs) to all output

mainloop:
   PORTB = 0           ' PORTB lines low to read buttons
   TRISB = $f0         ' Enable all buttons
   PORTD = 0           ' All LEDs off

   ' Check any button pressed to turn on LED
   If PORTB.7 = 0 Then ' If 4th button pressed...
      PORTD.3 = 1      ' 4th LED on
   Endif

   If PORTB.6 = 0 Then ' If 3rd button pressed...
      PORTD.2 = 1      ' 3rd LED on
   Endif

   If PORTB.5 = 0 Then ' If 2nd button pressed...
      PORTD.1 = 1      ' 2nd LED on
   Endif

   If PORTB.4 = 0 Then ' If 1st button pressed...
      PORTD.0 = 1      ' 1st LED on
   Endif

   Goto mainloop       ' Do it forever

   End