int0_wakeup.c - uses INT0 to wake from sleep mode.

/Demonstrates the use of int0 interrupt to wake from Sleep mode. Pushbutton on an int0 pin is used to wake from Sleep mode.

 
#include "pic24_all.h"


/// Interrupt Service Routine for INT0
void _ISRFAST _INT0Interrupt (void) {
  _INT0IF = 0;    //clear the interrupt bit
}

/// Switch1 configuration, RB7 shares INT0 pin on PIC24HGP202
inline void CONFIG_SW1()  {
  CONFIG_RB7_AS_DIG_INPUT();     //use RB7 for switch input
  ENABLE_RB7_PULLUP();           //enable the pullup
}

int main (void) {
  configBasic(HELLO_MSG);
  /** Configure the switch ***********/
  CONFIG_SW1();    //enables individual CN interrupt also
  /** Configure INT0 interrupt  */
  _INT0IF = 0;     //Clear the interrupt flag
  _INT0IP = 2;     //Choose a priority
  _INT0EP = 1;     //negative edge triggerred
  _INT0IE = 1;     //enable INT0 interrupt
  while (1) {
    outString("Entering Sleep mode, press button to wake.\n");

Finish sending characters before sleeping

    WAIT_UNTIL_TRANSMIT_COMPLETE_UART1();
    SLEEP();        //macro for asm("pwrsav #0")
  }
}