' Name        : VMETERX4.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : PIC12F675 or similar 8-pin
' Hardware    : Lab-X4 board
' Oscillator  : 4MHz internal
' Keywords    : ADCIN, SEROUT2
' 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-3 (RA4)
'

Define OSCCAL_1K 1        ' Calibrate internal oscillator

' 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


LCD   Var GPIO.1      ' LCD TX pin
adval Var Word        ' Create adval to store result
T2400 Con 396         ' 2400 baud, true

   ADCON0.7 = 1       ' Right justify result
   ANSEL = %00001000  ' Set AN3 analog, rest digital
   CMCON = 7          ' Analog comparators off

   Pause 500          ' Wait .5 second for LCD to init

mainloop:
   ADCIN 3, adval     ' Read channel 3 to adval (0-1023)

   adval = (adval */ 500)>>2    ' Equates to: (adval * 500)/1024
   Serout2 LCD, T2400, [$fe, 1] ' Clear screen
   Serout2 LCD, T2400, ["DC Volts= ", DEC (adval/100), ".", DEC2 adval] ' Display the decimal value

   Pause 100       ' Wait .1 second
   GoTo mainloop   ' Do it forever

   End