Help me with basic program for using PIC16f84

help on using 16f84

Hi there,
I am new on pic and I have troubles on getting my 16f84 to work. I wrote this simple basic program.

1. I used this free basic compiler and wrote the following. It should get the various indicated pins to be high / low. I wrote this delay subroutine but eventually remarked it out as I cannot even get the pins voltages correct.

_______________________________


bitset(rp0)
trisa=0
trisb=0
bitclear(rp0)

main:
ra.0=1
ra.1=1
ra.2=1
ra.3=1

rb.0=1
rb.1=1
rb.2=0
rb.3=1

'goto main:

'rem delay routing of 1.2s
'delay: i=200
' i2=200
' i3=10
' while i3>0
' while i2>0
' while i>0
' decr
' wend
' wend
' wend
'
' return

interrupt:

2. after using picbas, which is a free basic compiler, i obtained the following assembly code.

_______________________


include 'c:\pictools\16f84a.inc'
FUSES _XT_OSC
FUSES _WDT_OFF

DEVICE pic16c84,XT_OSC,WDT_OFF
org 0
JMP CC0
org 4
jmp INTERRUPT
CC0
; bitset(rp0)
setb RP0
; trisa=0
mov w,#0
mov 5,w
; trisb=0
mov w,#0
mov 6,w
; bi
jay says:
; bitclear(rp0)
clrb RP0
;
; main:
MAIN
; ra.0=1
mov w,#1
mov 13,w
; ra.1=1
mov w,#1
mov 14,w
; ra.2=1
mov w,#1
mov 15,w
; ra.3=1
mov w,#1
mov 16,w
;
; rb.0=1
mov w,#1
mov 17,w
; rb.1=1
mov w,#1
mov 18,w
; rb.2=0
mov w,#0
mov 19,w
; rb.3=1
mov w,#1
mov 20,w
;
; 'goto main:
;
; 'rem delay routing of 1.2s
; 'delay: i=200
; ' i2=200
; ' i3=10
; ' while i3>0
; ' while i2>0
; ' while i>0
; ' decr
; ' wend
; ' wend
; ' wend
; '
; ' return
;
; interrupt:
INTERRUPT
;

_____
(in it, i had too disable watchdog, i selected xt as i am using a 4mhz crystal.)

3. i then burnt in the machine code after assembling the above machine code using a jdm programmer/ and ic-prog

4. the circuitry connected to my 16f84a is as follows

pin 4 - a 20k resistor to 5V
pin 5 - 0V ref
pin 15 / 16 - a 4mhz crystal across
pin 15 - a cap to gnd 22uF
pin 16 - a cap to gnd 22uF
pin 17 - 5v

please help /advise.
thank you.

mike

Re: help on using 16f84

Hi there,

this site might help you:

h**p://www.mikroelektronika.co.yu/english/product/books/PICbook/0_Uvod.htm

It has an onlone PIC 16F84 complete book for free.
If you browse the site a little you will find a book about BASIC programming for PIC.

Hope it helps :idea:

Re: help on using 16f84

hi dear check th sight h**p://www.mikroelektronika.co.yu/english/product/books/PICbook/0_Uvod.htm

take care

Re: help on using 16f84

Hi mikelim,

pin 4 - a 20k resistor to 5V
pin 5 - 0V ref
pin 15 / 16 - a 4mhz crystal across
pin 15 - a cap to gnd 22uF
pin 16 - a cap to gnd 22uF
pin 17 - 5v

-----------------------------

pin 15 and 16 use 22pF and not 22uF
pin17 - 5 V must be pin 14 and not pin 17

Also check this out if you are using 16F84A and ic-prog:
**broken link removed**

hope this helps

help on using 16f84

if you are using a 40 pin ZIF drive in the programmer circuit , then make sure the position of your microcontroller in ZIF drive. Different pin microcontroller are placed at different locations in the ZIF drive. Good Luck.