' Name        : VMETERXU.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : MPASM
' Target PIC  : PIC18F4550 or similar type
' Hardware    : LAB-XUSB Experimenter Board
' Oscillator  : 20MHz external
' Keywords    : ADCIN, LCDOUT
' Description : PICBASIC PRO program to measure voltage (0-5VDC)
' and display on LCD with 2 decimal places. This program uses the
' */ operator to scale the ADC result from 0-1023 to 0-500. The */
' performs a divide by 256 automatically, allowing math which would
' normally exceed the limit of a word variable. Connect analog input
' to channel-0 (RA0).
'

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

' RESET_ORG can be set to move the BASIC program out of the way
' of any boot loader running from location 0, such as the
' Microchip USB boot loader
'Define RESET_ORG 800h

Define OSC 48      ' Core is running at 48MHz

' 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

' Define ADCIN parameters
Define ADC_BITS     10  ' Set number of bits in result
Define ADC_CLOCK     3  ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50  ' Set sampling time in uS

adval Var Word          ' Create adval to store result

   TRISA = %11111111    ' Set PORTA to all input
   ADCON1 = %00001010   ' Set PORTA analog...
   ADCON2 = %10000000   ' ...and right justify result
   Low PORTE.2          ' LCD R/W line low (W)
   Pause 500            ' Wait .5 second

mainloop:
   ADCIN 0, adval       ' Read channel 0 to adval (0-1023)
   adval = (adval */ 500) >> 2  ' Equates to: (adval * 500) / 1024

   LCDOut $fe, 1        ' Clear LCD
   LCDOut "DC Volts= ", DEC (adval/100) ,".", DEC2 adval ' Display the decimal value  
   Pause 100            ' Wait .1 second
   GoTo mainloop        ' Do it forever

   End