A/D conversion with PIC18F67J50

[ScaleRobotics]

Thanks mister_e ! I have flipped to page 299 to 302 so many times but never noticed the "D" to "N" change. Doh!

Do you think it is edited out because it is a shared address, only distinguished by the address share bit ADSHR in the WDTCON register?

Currently I have to:
@ bsf WDTCON,ADSHR 'flag address share bit
ADCON0 = %11111000 ' channels with a 0 is analog input, all others digital
@ bcf WDTCON,ADSHR
(or should I say I think? I have to....)

to set the aNcon0 register

(Despite all my mistakes, I am now getting valid conversion results, as of post 4)

[mister_e]

Holly crap, yeah, that make sense indeed. Yet another stupidity from Microchip

So my example will need some changes...

        '
        '       Configure ADC
        '       =============
        ANCON0  VAR BYTE EXT    ' not included in PBP2.50c
        ANCON1  VAR BYTE EXT    ' not included in PBP2.50c
        
        WDTCON.4 = 1    ' Switch to Alternate SFR
        ANCON0 = %10011110
               '  -xx------ Not Implemented
               '  1--1111-- AN7, & AN<4:1> = Digital
               '  -------0- AN0 = Analog
               
        ANCON1 = %11111111
               '  11111111- AN<15:10> = Digital
                                     
        WDTCON.4 = 0    ' Back to Default SFR

or

        '
        '       Configure ADC
        '       =============
        WDTCON.4 = 1    ' Switch to Alternate SFR
        
        ADCON1 = %10011110  ' alternate ANCON0
               '  -xx------ Not Implemented
               '  1--1111-- AN7, & AN<4:1> = Digital
               '  -------0- AN0 = Analog
               
        ADCON0 = %11111111  ' alternate ANCON1 
               '  11111111- AN<15:10> = Digital
                                     
        WDTCON.4 = 0    ' Back to Default SFR

By far, i prefer the first, easier to read

However, yours work.. keep it like that. If it's not broken, don't fix it!

[mister_e]

Side note... there's no real need to redefine ANCON1, ANCON0 as i did if you use ANCON1_ALT, ANCON0_ALT within your code. Those two are defined in PIC18EXT.BAS.

Having _ALT written at the right of the register name, may remember you to set/clear WDTCON.4 bit? Maybe

[ScaleRobotics]

Side note... there's no real need to redefine ANCON1, ANCON0 as i did if you use ANCON1_ALT, ANCON0_ALT within your code. Those two are defined in PIC18EXT.BAS.

Having _ALT written at the right of the register name, may remember you to set/clear WDTCON.4 bit? Maybe

Sweet! I did not see that either. May be time for glasses. And a lot cleaner than the way I was doing it, and I like the way you wrote the registry bits in the code. That would have kept me from having to divert my attention to and from tfm a lot!

Thanks for all the help.

Walter

[mister_e]

To me, comments are really important. So, on the long run... coding like that

        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

May indeed avoid to open the datasheet all the time, one thing is sure, it's easier to modify/understand later.