[SOLVED] LED flash with pic 12f1822

Amanda Lima said:

Hello people, I really need your help, how to configure the timer0 of pic 12f1822 to flash a led at a frequency of one second using CCS Compiler? **broken link removed**

Click to expand...

betwixt said:

Your crystal is 32MHZ.
Set TMR1 to use the internal clock as its source,
Set TMR1 pre-scaler to 8
Load the value 0xBEE9 in to TMR1. (TMR1H = 0xBE; TMR1L = 0xE9
Enable TMR1 interrupts and then GIE.

You now have an interrupt after 0.016663 seconds (= 60.01Hz)

Inside the ISR, reload TMR1 with the same value again then set a variable, lets call it "SixtyHz".

Now in the main() code loop keep checking to see if "SixtyHz" has been set, if it has, reset it and us it in the same way you used your external 60HZ signal.

Brian.

Click to expand...

#include <main.h>
int contador = 0;
#INT_TIMER1
void  TIMER1_isr(void)
{
contador++;
if(contador==1)
{
output_toggle(pin_a5);

contador = 0;
}
set_timer1(3036); // 0,5 segundo
clear_interrupt(int_timer1);
   }

void main()
{
   setup_adc_ports(sAN1|sAN2|sAN3);
   setup_adc(ADC_CLOCK_INTERNAL);
   setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);      //524 ms overflow
   set_timer1(3036);

   enable_interrupts(INT_TIMER1);
   enable_interrupts(GLOBAL);

//0,5s = 1us x 8 x(65536- carga TRM1)
// carga TRM1 = 65536 - 500000/8us
// carga TRM1 = 65536-62500
//carga TRM1 = 3036



   while(TRUE)
{
  }
    }

betwixt said:

Your crystal is 32MHZ.
Set TMR1 to use the internal clock as its source,
Set TMR1 pre-scaler to 8
Load the value 0xBEE9 in to TMR1. (TMR1H = 0xBE; TMR1L = 0xE9
Enable TMR1 interrupts and then GIE.

You now have an interrupt after 0.016663 seconds (= 60.01Hz)

Inside the ISR, reload TMR1 with the same value again then set a variable, lets call it "SixtyHz".

Now in the main() code loop keep checking to see if "SixtyHz" has been set, if it has, reset it and us it in the same way you used your external 60HZ signal.

Brian.

Click to expand...

#include <main.h>
int contador = 0;
#INT_TIMER1
void  TIMER1_isr(void)
{
contador++;
if(contador==1)
{
output_toggle(pin_a5);

contador = 0;
}
set_timer1(3036); // 0,5 segundo
clear_interrupt(int_timer1);
   }

void main()
{
   setup_adc_ports(sAN1|sAN2|sAN3);
   setup_adc(ADC_CLOCK_INTERNAL);
   setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);      //524 ms overflow
   set_timer1(3036);

   enable_interrupts(INT_TIMER1);
   enable_interrupts(GLOBAL);

//0,5s = 1us x 8 x(65536- carga TRM1)
// carga TRM1 = 65536 - 500000/8us
// carga TRM1 = 65536-62500
//carga TRM1 = 3036



   while(TRUE)
{
  }
    }