Hej Terry A. Steen. Tack fšr ditt meddelande 11:17 1999-10-21 -0400 enligt nedan:
>Hi, new guy here...

Welcome :)

>I am trying to read the A/D port on a PIC14000. I am clocking at 16MHz XTAL
>(want to try 20), going for 16bits.

16 bit true resolution is completely impossible.
I had almost 4*bit* noise before digital filter, so i was getting about 12bit real output.

Also, it is drifting with temeprature, so it do need the calibration algorithms described in the manual.

>  I am REAL unsure of the proper way to
>use the A/D input. I have followed the steps in the manual, but just don't
>seem to be getting anywhere. Does anybody have a skeleton of a simple --
>read AN0, so I can get this puppy rolling?
>
>Thanks!
>
>Terry 

I found this in my first and never-again PIC14000 project
think i cut-pasted it from a Micrichip demo code

         bcf     STATUS,RP0      ;BANK0
         clrf    ADTMRH          ;clear a/d timer for 16 bits
         clrf    ADTMRL
         bcf     PIR1,OVFIF      ;clear a/d timer overflow flag
         bcf     PIR1,ADCIF      ;clear a/d capture complete flag
         movlw   .50             ;500uS delay for signal to settle
         call    delay10

         bsf     STATUS,RP0      ;BANK1
;       bsf     PIE1,ADCIE      ;** enable a/d capture interrupt
         bsf     PIE1,OVFIE      ;## enable a/d timer overflow interrupt
         bsf     INTCON,PEIE     ;enable peripheral interrupt
         bcf     SLPCON,OSCOFF   ;leave main osc running during sleep for a/d
         bcf     STATUS,RP0      ;BANK0

         bcf     ADCON0,ADRST    ;start conversion

         sleep                   ;can sleep instead of next ad_wait loop

;ad_wait:
;       LEDSINC
;       btfss   PIR1,ADCIF      ;** wait until a/d capture
;       btfss   PIR1,OVFIF      ;## wait until a/d timer overflows
;       goto    ad_wait

ad_stop:bsf     ADCON0,ADRST    ;stop a/d
         btfsc   PIR1,ADCIF      ;## check if signal is greater than full scale
;       btfss   PIR1,OVFIF      ;** check is signal is greater than full scale
         goto    ad_ok
         movlw   0xff            ;if signal is too large, value = ffff
         movwf   ADCAPH
         movwf   ADCAPL
ad_ok:  
         bcf     PIR1,OVFIF      ;clear a/d timer overflow flag
         bcf     PIR1,ADCIF      ;clear a/d capture complete flag
         return


Good luck
/Morgan
Morgans Reglerteknik, HŠllekŒs, 277 35 KIVIK, SWEDEN
   tel +46(0)414-446620, fax -70331,   mrt@iname.com