A/D conversion with PIC18F67J50

[mister_e]

You conversion clock seems a bit high @48MHz operation, and your first example in C used ANCON0, not yours.... yet...

While it's not a problem for now, one day you may need to disable some analog feature on this PIC... however, seems ANCON0 and ANCON1 are not included in PBP 2.50c, so I guess the following would be handy one day or another.

        '
        '       Configure ADC
        '       =============
        ANCON0  VAR BYTE EXT    ' not included in PBP2.50c
        ANCON1  VAR BYTE EXT    ' not included in PBP2.50c
        
        ANCON0 = %10011110
               '  -xx------ Not Implemented
               '  1--1111-- AN7, & AN<4:1> = Digital
               '  -------0- AN0 = Analog
               
        ANCON1 = %11111111
               '  11111111- AN<15:10> = Digital
                                     
        ADCON0 = %00000001
               '  0-------- VCFG1, Vref- 0 = AVss (1=AN2)
               '  -0------- VCFG2, Vref+ 0 = AVdd (1=AN3) 
               '  --0000--- CHS<3:0>, Channel select -- 0
               '  ------0-- Go/Done, don't care for now
               '  -------1- ADON, Enable ADC
                  
        ADCON1 = %10000111
               '  1-------- ADFM, Right justified result
               '  -0------- ADCAL, Normal A/D converter operation
               '  --000---- ACQT<2:0>, A/D Aquisition time = 0 Tad
               '  -----111- ADCS<2:0>, A/D conversion clock = FRC
                
        '
        '       Hardware Aliases
        '       ================
        GoDone      var ADCON0.1 ' StartConversion = 1, Conversion done = 0
        
        '
        '       Software Variables
        '       ==================
@ADVal = ADRESL
        ADVal       VAR WORD EXT
        
Start:
        pauseus 10  ' Acquisition time        
        GoDone = 1
        While GoDone : Wend
        LCDOUT $FE, 1, "Value: ", DEC ADVal
        PAUSE 250
        GOTO START

EDIT: for some odd reason, ANCON0 & ANCON1 are commented in PIC18EXT.BAS, i'd sent an e-mail to Melabs, obviously they must have a reason for that.