rtcc.c - Demonstrates using the secondary oscillator with a 32768 Hz oscillator

See chapter 12.

 
#include "pic24_all.h"


volatile uint16_t u16_seconds = 0;

//Interrupt Service Routine for Timer1
void _ISRFAST _T1Interrupt (void) {
  u16_seconds++;
  _T1IF = 0;     //clear the timer interrupt bit
}

void  configTimer1(void) {
  T1CON = T1_OFF | T1_IDLE_CON | T1_GATE_OFF
          | T1_SYNC_EXT_OFF
          | T1_SOURCE_EXT
          | T1_PS_1_1 ;  //
  PR1 = 0x7FFF;                    //period is 1 second
  _T1IF = 0;                       //clear interrupt flag
  _T1IP = 1;                       //choose a priority
  _T1IE = 1;                       //enable the interrupt
  T1CONbits.TON = 1;               //turn on the timer
}

int main(void) {
  __builtin_write_OSCCONL(OSCCON | 0x02);    //    OSCCON.SOSCEN=1;
  configBasic(HELLO_MSG);   //say Hello!
  configTimer1();
  while (1) {
    outString("Seconds: ");
    outUint16Decimal(u16_seconds);
    outString("\n");
    while (!IS_TRANSMIT_COMPLETE_UART1());
    SLEEP();
  }
}