Reposted with a [PIC] tag for more visibility.

BAJ

On Sun, Jan 20, 2013 at 07:45:15AM -0800, mircea2012 wrote:
Hi all.
I am new on this site and I have some questions about Pic microcontrollers.
First I am a beginner in Pic microcontroller. I bought a development board
from Matrix Multimedia, HP488, but I dont know why I fail with a smalle
program.

The program must flash a led with a delay (4 sec) using TMR0.
So, from my calculations, using formula :=20
Freq. out =3D Freq. osc / [prescaler * (256 - TMR0) * count]
The prescaler is 1 : 256; TMR0 is 0, anf the frequency oscilator is 4Mhz
(osccon =3D 0b01100000)
An instruction is executed in 4 clock cycles. So the frequency clock is 4Mh=
z
/ 4 =3D 1Mhz.
count =3D 61.
I use sourceBoost IDE, and the compiler is BoostC.

Look my code :=20

    #include<system.h>=20
    unsigned int counter =3D 0;=20

    void Delay(void)=20
    {   =20
      if(intcon & 2)                   // check if TMR0IF is set=20
       {                     =20
          clear_bit( intcon, 2 );     // if TMR0IF is set, clear this bit
          counter =3D counter + 1;      // increments the counter      =20
          if(counter =3D=3D 61)          =20
            {
               counter =3D 0;
               portb =3D ~portb;        // flash the Led 0 of Port B
            }
       }            =20
    }

    void main(void)=20
    {   =20
        trisb =3D 0x00;                    // set all pins of Port B as out=
put
        portb =3D 0x01;                    // RB0 is high=20
        tmr0 =3D 0;                        // the value of TMR0 register is
zero.
        cmcon =3D 0x07;                    // comparators is off.
        option_reg =3D 0b00000111;         // prescaler is assigned to the
WDT, prescaler 1:256
        intcon =3D 0b10100000;             // GIE - enable, TMR0IE - enable
        while(1)
        {   }=20
    }

The program compiles fine, upload fine, but dont show me the led flashing.
What I am doing wrong ? Are there any configuration settings that I am not
aware of ?


--=20
Byron A. Jeff
Chair: Department of Computer Science and Information Technology
College of Information and Mathematical Sciences
Clayton State University
http://faculty.clayton.edu/bjeff
--=20
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