' Name        : ADCXU.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : PIC16F877 or similar type
' Hardware    : LAB-XUSB Experimenter Board
' Oscillator  : 20MHz external
' Keywords    : LCDOUT
' Description : PICBASIC PRO program to read pots on 16F877 ADC.
'

' Define LOADER_USED to allow use of the boot loader.
' This will not affect normal program operation.
Define LOADER_USED 1
Define OSC 20

' Define LCD pins
Define LCD_DREG  PORTD
Define LCD_DBIT  4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG  PORTE
Define LCD_EBIT  1

' Allocate variables
x Var Byte
y Var Byte

   ADCON1 = %00001010   ' Set PORTA to analog inputs
   Low PORTE.2          ' LCD R/W line low (W)
   Pause 100            ' Wait for LCD to start
   GoTo mainloop        ' Skip subroutines

' Subroutine to read a/d convertor
getad:
   Pauseus 50           ' Wait for channel to setup
   ADCON0.1 = 1         ' Start conversion
   Pauseus 50           ' Wait for conversion
   Return

' Subroutine to get pot x value
getx:
   ADCON0 = $01         ' Set A/D Channel 0, On
   Gosub getad
   x = ADRESH
   Return

' Subroutine to get pot y value
gety:
   ADCON0 = $05         ' Set A/D Channel 1, On
   Gosub getad
   y = ADRESH
   Return

mainloop:
   GoSub getx           ' Get x value
   GoSub gety           ' Get y value
   Lcdout $fe, 1, "x=", #x, " y=", #y   ' Send values to LCD
   Pause 100            ' Do it about 10 times a second
   GoTo mainloop        ' Do it forever

   End