Hello.


I'm trying to use the adc on my atmega48, but I'm having a little difficulties.

Why can't I load anything into the ADC registers like ADMUX and ADCSRA?
I've tried using LDI and MOVW and MOV, but AVRstudio tells me its an invalid register or that oprand 2 is out of range.


here is the current code:



.include "m48def.inc"

.def temp =r16 ;definer variabler
.def temp2 =r20
.def delay =r17
.def delay2 =r18
.def delay3 =r19


What am I doing wrong?



init:
bclr PRADC ;Skru på ADC
bset ADEN ;
bset REFS1 ;Referanse =AVCC
bset ADLAr ;resultatet er venstrejustert
bset ADPS2 ;
bset ADPS1 ;prescaler =1/128
bset ADPS0 ;
ser temp ;temp=0xff
out DDRB,temp ;PORTB er utganger
clr temp ;temp=0x00
out DDRC,temp ;PORTC er innganger

loop:

bset adsc
adloop:
sbrc ADCSRA,ADSC
rjmp adloop
movw temp,ADCH
out portb,temp
rjmp loop

 

Hey

Sorry I forgot about the box...

Shouldn't there be an "edit" box somewhere?

Anyway I also get an error message for the "sbrc ADCSRA,ADSC" line, why can't i test this bit? I think the error message is "operand 2 is out of range"

The other part I was wondering about was how I'm supposed to copy the ADCH register, I can't figure out which instruction to use.

I'm new to Atmel devices as you can probably tell.


Edit

I see the Edit box disappears after a while.

 

Your problem is that most people around here are also new to Atmels. You may get a better response over at AVR Freaks.

Mike.

 

Okay.

Thanks Pommie.

Just made a thread at AVRfreaks. Hope I get an answer there.