Help PIC16F84A

M

Mihindu_gajaba

New Member

• Nov 25, 2007

• #1

Hi , i wanna turn a led on and then off. and that should be in a loop ..
so i have written a code. is it correct and am i supporsed to to use a cristal. of can i use the internal clock i'm Using PIC16F84A

Please help Me.

code :

__CONFIG _CP_OFF & _WDT_OFF & _BOREN_OFF & _MCLRE_OFF & _LVP_OFF & _INTOSC_OSC_NOCLKOUT & _PWRTE_ON

bsf STATUS,5
movlw 00h
movwf TRISA
bcf STATUS,5

Start movlw 02h
movwf PORTA
movlw 00h
movwf PORTA
goto Start
end

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Nov 25, 2007

• #2

I suggest you lose the antique 16F84, and use a more modern device - and my first tutorial does exactly what you want, using the F84's replacement, the 16F628 - it would be trivial to convert to the 84 if you really had to.

 

A

aristos

Member

• Nov 25, 2007

• #3

between movwf PORTA & movlw 00h you must have a delay.and i think there is a porb with your fuses.16f84a doesn't have internal osc.

 

M

Mihindu_gajaba

New Member

• Nov 25, 2007

• #4

aristos said:

between movwf PORTA & movlw 00h you must have a delay.and i think there is a porb with your fuses.16f84a doesn't have internal osc.

Click to expand...

hey are you sure , that means i have to use an external osc ( Crystal )

 

A

aristos

Member

• Nov 25, 2007

• #5

yes.and you should have a loop between movwf PORTA & movlw 00h.you can use a rc osc.

 

A

aristos

Member

• Nov 25, 2007

• #6

sorry not loop,a subroutine.

 

M

Mihindu_gajaba

New Member

• Nov 25, 2007

• #7

aristos said:

sorry not loop,a subroutine.

Click to expand...

rc osc means we're doing what the crystal do by coding right ?

 

blueroomelectronics

Well-Known Member

• Nov 25, 2007

• #8

Yep, here's a link, not sure about the 16F84 getting an I/O pin out of the deal though.
PS your program will probably run so fast you wont see it blink.
https://www.mikroe.com/en/books/picbook/2_02chapter.htm**broken link removed**

 

M

Mihindu_gajaba

New Member

• Nov 25, 2007

• #9

Wow thanks