18F2550 Blinking LED With Pickit 2

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- 22nd April 2010, 19:42
kiewic

18F2550 Blinking LED With Pickit 2

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.

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.

Code:

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.

Code:

;_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.
- 23rd April 2010, 00:17
mackrackit

The configs

Code:

__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

Code:

OSCCON = %01110000 DEFINE OSC 8

just little changes...
- 23rd April 2010, 03:53
kiewic

Hello

Thanks mackrackit, but unfortunately it doesn't work. I made the changes you recommended, but the PIC continues not working :(
- 23rd April 2010, 04:03
mackrackit

How is the MCLR pin connected?

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

Code:

__CONFIG _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H
- 23rd April 2010, 04:30
mackrackit

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

Code:

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
- 23rd April 2010, 04:40
kiewic

Mmm nop

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

I tried changing that configuration, but nothing happened.
- 23rd April 2010, 05:43
mackrackit

Might be a stupid question but are you compiling for the correct chip?
Are you using MCS?
- 23rd April 2010, 05:53
kiewic

Yes

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.