Analog Input Problem

[mas]

I am using PIC 16F877a

Just trying the adc isn't working with me

I wrote a code in ASM to read the channel 0 input, convert it, and display the result as >>
ADRESH on PORTB
ADRESL on PORTD

Here is my code

	CBLOCK 0x20
	COUNT
	ENDC




	BANKSEL TRISD

	MOVLW B'00000000'
	MOVWF TRISD
	MOVWF TRISB
	MOVLW B'11111111'
	MOVWF TRISA
	

START

	BANKSEL ADCON0
	MOVLW B'00000001'
	MOVWF ADCON0

	BANKSEL ADCON1
	MOVLW B'00000000'
	MOVWF ADCON1
	
	MOVLW 255
	MOVWF COUNT
	CALL DELAY

	BANKSEL ADCON0
	BSF ADCON0,2
L	BTFSC ADCON0,2
	GOTO L
	
	BANKSEL ADRESH
	MOVF ADRESH,W
	BANKSEL PORTB
	MOVWF PORTB
	BANKSEL ADRESL
	MOVF ADRESL,W
	BANKSEL PORTD
	MOVWF PORTD
	GOTO START


DELAY
	DECFSZ COUNT
	GOTO DELAY
	RETURN

Is there something wrong with the code ??

 

[Pommie]

What speed is the pic running at? If it is more than 1.25MHz then you need to look at section 11.2 of the data sheet.

Mike.

 

[Nigel Goodwin]

You might also consult my tutorials, which explain how to use the analogue inputs.