Electrical – How to generate 1min timer interrupt in PIC24F

pictimer

I m trying to generate a 1 minute interrupt using
pic24F seires… To be specific PIC24Fj64GA306

Here is the code snippet

#include "xc.h"
#include "newxc16_header.h"

void TimerInit(void);
void __attribute__((__interrupt__)) _T1Interrupt(void);



void main() 
{
    ANSB = 0x0000;
    TRISBbits.TRISB0 = 0;
   TRISBbits.TRISB1 = 1;
    TRISBbits.TRISB2 = 1;
   TRISBbits.TRISB3 = 1;
    TRISBbits.TRISB4 = 1;
    TRISBbits.TRISB5 = 1;
    TRISBbits.TRISB6 = 1;
   TRISBbits.TRISB7 = 1;
   TRISBbits.TRISB8 = 1;
   TRISBbits.TRISB9 = 1;
   TRISBbits.TRISB10 = 1;
   TRISBbits.TRISB11 = 1;
   TRISBbits.TRISB12 = 1;
   TRISBbits.TRISB13 = 1;
   TRISBbits.TRISB14 = 1;
   TRISBbits.TRISB15 = 1;

   TimerInit();

   T1CONbits.TON = 1; //start the timer

   while(1)
   {      

   }
 }

void TimerInit(void)
{
  PR1 = 0x1FFF;  //8191
  IPC0bits.T1IP = 5;     //set interrupt priority
  T1CONbits.TCKPS = 0x03; //timer prescaler bits
  T1CONbits.TCS = 0;   //using FOSC/2 

  IFS0bits.T1IF = 0;    //reset interrupt flag
  IEC0bits.T1IE = 1;     //turn on the timer1 interrupt

}


  void __attribute__((__interrupt__, auto_psv)) _T1Interrupt(void)
   {
     T1CONbits.TON = 0;   //stop the timer
     LATBbits.LATB0 = ~LATBbits.LATB0;  //Toggle output to LED
    IFS0bits.T1IF = 0;   //reset the interrupt flag
     T1CONbits.TON = 1;   //start timer
  }

For testing purpose i m trying to generate Timer interrupt after every 1 sec…

But the issue is i m not able to generate any interrupt.

Please help me.

Thanks in advance

Best Answer

I found that PIC24f controller generates interrupt max for 4 sec, using external oscillator of 8MHz. so i m generating an timer interrupt for 1 sec and calculating secs... once it is done for 1 min i do the process.... here is the code snippet

void __attribute__((__interrupt__, auto_psv)) _T1Interrupt(void)
  {

   IFS0bits.T1IF = 0;   //reset the interrupt flag 
   Timer_flag = 1;

 }

the above code is for timer isr

Timer init

void TimerInit(void)
{
   PR1 = 0x2FFF;     //8191
   IPC0bits.T1IP = 1;    //set interrupt priority
   T1CONbits.TCKPS = 0x03; //timer prescaler bits
   T1CONbits.TCS = 0;   //using FOSC/2 

   IFS0bits.T1IF = 0;    //reset interrupt flag
   IEC0bits.T1IE = 1;    //turn on the timer1 interrupt

 }

Timer code in main

if(Timer_flag == 1)
{
      Timer_flag = 0;
      if(second++ == 60)
       {
           second = 0;
           //code
        }
}
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