> I have a PIC16F88 chip I'm trying to wire up on a breadboard to flash
> an LED, running the internal RC oscillator.  I'm using the B Knudsen
> CC5X compiler with MPLAB.  The Config word is 3FD0h.  I have WDT off,
> PWRT on, MCLR off, BODEN on, LVP on, CPD off, Debuger off, and CCPMX
> is on.

Below is some absolute assembly code that simply blinks an LED on RB0.
It's not C, but it's simple to understand, and it has the proper
config to use 8MHz intRC.

-Scott



; Title: blink88.asm
; Author: Scott Larson
; Date: Jan 2 2006
; Version: 0.1
; PIC: 16F88
; Description: LED blinker, portb.0
; 8MHz internal RC
;

;****Include and config****

	include	"P16F88.INC"
	__CONFIG _CONFIG1, _CP_OFF&_WDT_OFF&_PWRTE_ON&_INTRC_IO&_MCLR_OFF&_LVP_OFF

;*****Set up the Constants****

COUNT1 equ 20h ;First counter for Pause
COUNT2 equ 21h ;Second counter for Pause
COUNT3 equ 22h ;Third counter for Pause
BSHADOW equ 23h ;shadow register for PORTB	
	
;****Set up PORTB as output, which will remain output****

	banksel TRISB ;switch to bank 1
	clrf TRISB   ;Set PORTB to output.
	banksel PORTB  ;Switch back to Bank 0


;****flash LED****

Start
	banksel OSCCON		;
	movlw b'01110000'	;8MHz intrc
	movwf OSCCON
	banksel PORTB
LOOP
	bsf BSHADOW,0	;use shadow register
	movfw BSHADOW	;to solve the RMW problem
	movwf PORTB	;turn LED at pin0 on
	call Pause	;pause
	clrf PORTB	;turn LED off
	clrf BSHADOW
	bsf BSHADOW,1
	movfw BSHADOW
	movwf PORTB	;turn LED at pin1 on
	call Pause	;pause
	clrf PORTB
	clrf BSHADOW
	goto LOOP	;loop


;****Pause subroutine

Pause
	movlw 03h		;Change this number to change the length of Pause
	movwf COUNT3
	movlw 0ffh
	movwf COUNT1
	movwf COUNT2
	
Pause1
	decfsz COUNT1,1
	goto Pause1
	decfsz COUNT2,1
	goto Pause1
	decfsz COUNT3,1
	goto Pause1
	return

	end







On 1/13/07, Paul Anderson <wackyvorlon@gmail.com> wrote:
> I have a PIC16F88 chip I'm trying to wire up on a breadboard to flash
> an LED, running the internal RC oscillator.  I'm using the B Knudsen
> CC5X compiler with MPLAB.  The Config word is 3FD0h.  I have WDT off,
> PWRT on, MCLR off, BODEN on, LVP on, CPD off, Debuger off, and CCPMX
> is on.
>
> I programmed the chip using the Olimex PG4 with the ICSP header and
> icprog on an XP system. It wrote and verified successfully.  I
> disconnect the programmer, and wire up a 7805 with a cap going from
> it's output to ground.  Wire up Vdd to +5v, Vss to gnd.  I have an LED
> on pin 1, through a 470 ohm resistor to gnd.  I checked with a
> voltmeter and the regulator is outputting 5.07v.  When I apply power
> to the circuit, the LED may or may not stay lit or flicker.  It seems
> most acutely affected by running my finger underneath breadboard where
> the chip is sitting, and the response of the LED is somewhat random.
>
> Any thoughts on why it's not running?  I can supply the code I'm
> using, it's from Spark Fun's blink.c, but modified to use with the F88
> and CC5x.  All help is greatly appreciated.
>
> --
> Paul Anderson
> VE3HOP
> wackyvorlon@gmail.com
> http://www.oldschoolhacker.com
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>


-- 
Scott Larson
1136 W. Oakdale Apt. 1
Chicago, Il, 60657
619-400-9775
http://goldscott.com
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