18F2550 Blinking LED With Pickit 2

[kiewic]

Hi.

I'm trying to make a PIC 18F2550 blinks using pickit 2 and the internal oscillator. But it doesn't do it. Here is what I have tried.

1. I have the following code.

OSCCON = $70            'Int CLK 8MHz
OSCTUNE.6 = 1           'PLL 4x
ADCON1= %00001111       '$0F = disable A/D converter

TRISA = %00000000       'All pins are outputs
TRISB = %00000000           
TRISC = %00000000           

DEFINE OSC 32            '4x 8MHz

flip:
PORTC.0 = 1             'Turn on LED
PAUSE 500               'Delay for .5 seconds
PORTC.0 = 0             'Turn off LED
PAUSE 500
GOTO flip

END

2. This is my configuration on 18F2550.INC file.

        LIST
        LIST p = 18F2550, r = dec, w = -311, w = -230, f = inhx32
        INCLUDE "P18F2550.INC"	; MPASM  Header
        __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
        __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
        __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L & 0DFh
        
        __CONFIG    _CONFIG1H, _FOSC_INTOSCIO_EC_1H
        __CONFIG    _CONFIG2H, _WDT_OFF_2H & _WDTPS_512_2H
        
        NOLIST

3. I supposed the circuit is correct, because it runs with the following assambler code using MPLAB.

;_INTRC_OSC_NOCLKOUT

#include <p18F2550.inc>

    cblock 0x20
Delay1                   ; Define two file registers for the
Delay2                   ; delay loop
     endc
      
     org 0
Start:
;     bsf       STATUS,RP0          ; select Register Page 1
     bcf       TRISC,0             ; make IO Pin B.0 an output
;     bcf       STATUS,RP0          ; back to Register Page 0
MainLoop:
     bsf       PORTC,0             ; turn on LED C0
OndelayLoop:
     decfsz    Delay1,f            ; Waste time.  
     goto      OndelayLoop         ; The Inner loop takes 3 instructions per loop * 256 loopss = 768 instructions
     decfsz    Delay2,f            ; The outer loop takes and additional 3 instructions per lap * 256 loops
     goto      OndelayLoop         ; (768+3) * 256 = 197376 instructions / 1M instructions per second = 0.197 sec.
                                   ; call it a two-tenths of a second.
      
     bcf       PORTC,0             ; Turn off LED C0
OffDelayLoop:
     decfsz    Delay1,f            ; same delay as above
     goto      OffDelayLoop
     decfsz    Delay2,f
     goto      OffDelayLoop
     goto      MainLoop            ; Do it again...
     end

Can you help me? Thanks.

[mackrackit]

The configs

        __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
        __CONFIG    _CONFIG1H, _FOSC_INTOSCIO_EC_1H
        __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
        __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
        __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L & 0DFh

Top of code

OSCCON = %01110000
DEFINE OSC 8

just little changes...

[kiewic]

Thanks mackrackit, but unfortunately it doesn't work. I made the changes you recommended, but the PIC continues not working

[mackrackit]

How is the MCLR pin connected?

If it is not connected to anything then change the 3H line to

__CONFIG    _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H

[mackrackit]

I just tested this on a 4550 (I do not have a 2550) and it works as expected.

DEFINE OSC 8
@ __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@ __CONFIG    _CONFIG1H, _FOSC_INTOSCIO_EC_1H
@ __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
@ __CONFIG    _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H
@ __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L & 0DFh
OSCCON = %01110000

    TRISD = %00000000
    TRISC = %00000000
    flip:
    HIGH PORTD.7
    PORTD.6 = 1             'Turn on LED
    PORTC.0 = 1
    PAUSE 500               'Delay for .5 seconds
    PORTD.6 = 0             'Turn off LED
    PORTC.0 = 0
    PAUSE 500
    GOTO flip

[kiewic]

The MCLR pin is connected directly to the first pin of the Pickit 2.

I tried changing that configuration, but nothing happened.

[mackrackit]

Might be a stupid question but are you compiling for the correct chip?
Are you using MCS?

[kiewic]

Yes, 18F2550 is selected on the combo box.

I'm using MicroCode Studio 3.0.0.5 and PICBASIC PRO 2.50B. When I compile, it uses the MPLAB assembler and it opens and closes a console window.