config for adc in proton

[arash]

Hi all.
Do you know how can i define Vref+ and Vref- in proton (Externall vref)

[ABBOSE]

I interface the internal AD converter with PIC 16F877 for some load measurement purpose.
Follow the following step.

        Device = 16F877
        XTAL 4
        ALL_DIGITAL = TRUE
        PORTB_PULLUPS = OFF      ' Enable PORTB pull-ups
 
       ADIN_RES   8            ' Set the AD resolution to 10
      ADIN_TAD   32_FOSC   'FOR AD CLOCK SEE PROTON HELP FOR MORE DETAILS               
       ADIN_STIME   200                 ' Allow 100us for charge time, see proton help
     Dim RAW       as byte

TRISA = %11111111   ‘ All port a in
TRISB = %00000000   ‘All portb out

ADCON1 = %0000001   ' Set PORTA analog and right justify result

         ‘ set vref and input of AD for more see PIC data sheet 3029b for 16f877

st:
      RAW = ADIN 0
      PORTB = RAW
      DELAYMS 1000
      goto st
      End

ABBOSE