[SOLVED] PIC18F252 & XC8: LED Flashing

[megacrypto]

I just moved to PIC18 to maybe make use of the better functions XC8 has for them (especially SPI) and I got the PIC18F252. Now before I get to SPI, I have to through all the initial learning curve step, which begin with flashing an LED.

here is my code:

config.h

// PIC18F252 Configuration Bit Settings


// CONFIG1H
#pragma config OSC = HS       // Oscillator Selection bits (RC oscillator w/ OSC2 configured as RA6)
#pragma config OSCS = OFF       // Oscillator System Clock Switch Enable bit (Oscillator system clock switch option is disabled (main oscillator is source))

// CONFIG2L
#pragma config PWRT = OFF       // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOR = OFF        // Brown-out Reset Enable bit (Brown-out Reset disabled)
#pragma config BORV = 20        // Brown-out Reset Voltage bits (VBOR set to 2.0V)

// CONFIG2H
#pragma config WDT = OFF        // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))
#pragma config WDTPS = 128      // Watchdog Timer Postscale Select bits (1:128)

// CONFIG3H
#pragma config CCP2MUX = ON     // CCP2 Mux bit (CCP2 input/output is multiplexed with RC1)

// CONFIG4L
#pragma config STVR = OFF       // Stack Full/Underflow Reset Enable bit (Stack Full/Underflow will not cause RESET)
#pragma config LVP = OFF        // Low Voltage ICSP Enable bit (Low Voltage ICSP disabled)

// CONFIG5L
#pragma config CP0 = OFF        // Code Protection bit (Block 0 (000200-001FFFh) not code protected)
#pragma config CP1 = OFF        // Code Protection bit (Block 1 (002000-003FFFh) not code protected)
#pragma config CP2 = OFF        // Code Protection bit (Block 2 (004000-005FFFh) not code protected)
#pragma config CP3 = OFF        // Code Protection bit (Block 3 (006000-007FFFh) not code protected)

// CONFIG5H
#pragma config CPB = OFF        // Boot Block Code Protection bit (Boot Block (000000-0001FFh) not code protected)
#pragma config CPD = OFF        // Data EEPROM Code Protection bit (Data EEPROM not code protected)

// CONFIG6L
#pragma config WRT0 = OFF       // Write Protection bit (Block 0 (000200-001FFFh) not write protected)
#pragma config WRT1 = OFF       // Write Protection bit (Block 1 (002000-003FFFh) not write protected)
#pragma config WRT2 = OFF       // Write Protection bit (Block 2 (004000-005FFFh) not write protected)
#pragma config WRT3 = OFF       // Write Protection bit (Block 3 (006000-007FFFh) not write protected)

// CONFIG6H
#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write protected)
#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block (000000-0001FFh) not write protected)
#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM not write protected)

// CONFIG7L
#pragma config EBTR0 = OFF      // Table Read Protection bit (Block 0 (000200-001FFFh) not protected from Table Reads executed in other blocks)
#pragma config EBTR1 = OFF      // Table Read Protection bit (Block 1 (002000-003FFFh) not protected from Table Reads executed in other blocks)
#pragma config EBTR2 = OFF      // Table Read Protection bit (Block 2 (004000-005FFFh) not protected from Table Reads executed in other blocks)
#pragma config EBTR3 = OFF      // Table Read Protection bit (Block 3 (006000-007FFFh) not protected from Table Reads executed in other blocks)

// CONFIG7H
#pragma config EBTRB = OFF      // Boot Block Table Read Protection bit (Boot Block (000000-0001FFh) not protected from Table Reads executed in other blocks)

main.c

#define _XTAL_FREQ 16000000                  //4Mhz FRC internal osc
#include <xc.h>
#include <stdio.h>
#include <stdlib.h>
#include "config.h"

void main(void) {
    INTCON = 0;
    INTCON2 = 0;
    INTCON3 = 0;
    TRISB6 = 0;
    TRISB7 = 0;

    while(1){
        LATB6 = 0;
        LATB7 = 1;
        for ( int i = 0; i < 100; i++ ){
             __delay_ms(10);
        };
        LATB6 = 1;
        LATB7 = 0;
        for ( int i = 0; i < 100; i++ ){
             __delay_ms(10);
        };
    }

}

Im using an external 16MHz crystal.

When the program runs, LED 2 (LATB7) goes on and LED 1 (LATB6) stays off. It should be alternating, but it doesn't

Thanks you all

 

[Easyrider83]

Ansel = 0;
anselh = 0;

 

[megacrypto]

Ansel = 0;
anselh = 0;

I tried this but when compiling it gave back:

main.c:25: error: undefined identifier "ANSEL"
main.c:26: error: undefined identifier "ANSELH"

although they come up when i use auto-complete while typing

 

[milan.rajik]

Maybe ADCON1.

 

[megacrypto]

Maybe ADCON1.

with ADCON1 = 0 it compiles but still same result.

could it be something with the external oscillator and the frequency I defined. Im using a 16MHz crystal?!

 

[milan.rajik]

Maybe ADCON1 should be 0x0F. Check the datasheet ADC section.

 

[megacrypto]

As it turned out to be (first time to come across this) MCLR is not included in the configuration bits as like in the previous 16F's that I used, so (as someone pointed out and) as per the datasheet:

A Power-on Reset pulse is generated on-chip when VDD rise is detected. To take advantage of the POR circuitry, just tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay.

and so, I connected the MCLR pin to Vdd and that was it

Here is the final code (config.h is the same as in first post):

main.c

#define _XTAL_FREQ 16000000

#include <xc.h>
#include "config.h"


void main(void) {
    TRISB = 0;
    LATB6 = 0;
    LATB7 = 1;
    while(1){
        for ( unsigned char i = 0; i < 100; i++ ){
            __delay_ms(10);
        }
        LATB6 = ~LATB6;
        LATB7 = ~LATB7;
    }

}

 

[milan.rajik]

If you have enebale MCLR then you have to pull-up MCLR using a 10k resistor to +5V.