f_10_18_intfsm_new.c

* Use 10 MHz crystal frequency. * Use Timer0 for ten millisecond looptime. * Blink "Alive" LED e

#include "config.h"
#include "delay.h"
#include "serial.c"
#include "serio.c"

#define OFF_STATE 0
#define ON_STATE 1
#define BLINK_STATE 2
#define STOP_STATE 3

void print_debug(void);

volatile unsigned char state, led_blink;
volatile unsigned char led_on, int_flag;

#if defined(HI_TECH_C)
void interrupt pic_isr(void)
#endif
#if defined(__18CXX)
#pragma interrupt pic_isr
void pic_isr(void)
#endif
{
  if (INT0IF) { 
    ISR_DelayMs(30); //debounce
    INT0IF = 0; int_flag = 1;
    switch(state) {
     case OFF_STATE: // exited rising edge
      state = ON_STATE;
      led_on = 1; // turn on led
      break;
     case ON_STATE: // exited rising edge
      if (RB7) {
      // change to falling edge trigger
       INTEDG0 = 0;  
       led_blink = 1; state = BLINK_STATE;
      }
      else {
       led_on = 0; state = OFF_STATE;
      }
      break;
     case  BLINK_STATE: // exited on falling edge
      led_blink = 0;led_on = 1;
      // change to rising edge trigger
      INTEDG0 = 1; state = STOP_STATE;
      break;
     case STOP_STATE: // exited on rising edge
       led_on = 0;
       state = OFF_STATE;
       break;
    }//end switch
  }// end if(INT0IF)
}//end pic_isr

void print_debug(void){
     printf("State: %d, Led_on: %d, led_blink: %d",
             state,led_on,led_blink); pcrlf();
}

void main(void){
  // 19200 in HSPLL mode, crystal = 7.3728 MHz 
  serial_init(95,1);
  RBPU = 0; // weak pullups enabled
  // set RB0 for input, rising edge interrupt initially
  TRISB = 0xEF;  //RB4 is output, others inputs
  INTEDG0 = 1; // rising edge
  RB4 = 0; // turn LED off
  printf("INT0 FSM started (with debug).");pcrlf();
  state = OFF_STATE; led_blink = 0; led_on = 0;
  // enable interrupts
  IPEN = 0; INT0IF = 0; INT0IE = 1; PEIE = 1; GIE = 1; 
  print_debug();
  while(1) {
    if (int_flag) {
        print_debug(); int_flag = 0;
    }
    if (led_blink) {
      //LED toggle, delay
      if (LATB4) RB4 = 0; else RB4 = 1;
      DelayMs(250); DelayMs(250); 
    } 
    else if (led_on) RB4 = 1;
    else RB4  = 0;    
  }
}

//for MCC18, place the interrupt vector goto
#if defined(__18CXX)
#if defined(HIGH_INTERRUPT)
#pragma code HighVector=HIGH_INTERRUPT
#else
#pragma code HighVector=0x0008  
#endif
void HighVector (void)
{
    _asm goto pic_isr _endasm
}
#pragma code
#endif