Applications of Embe ...

 #include <main.h> // the file main.h with the

                             // initial settings is included

                             // This file must be placed in the same

                             // folder with the project

                             // Also the 18F4550.h file must exist

                             // in the same folder with the project

#byte PORTD =0xF83 // We attribute to the memory position 0xF83

                                 // the name PORTD

                                 // This means that we define a 8 bit

                                 // variable whose value will be stored

                                 // to the memory position F83h

                                 // The memory position F83h is the PORTD

                                 // data register

#byte PORTB=0xF81  // We attribute to the memory position 0xF81

                                 // the name PORTD

                                 // This means that we define a 8 bit

                                 // variable whose value will be stored

                                 // to the memory position F81h

                                 // The memory position F81h is the PORTD

                                 // data register

#byte PORTC=0xF82  // We attribute to the memory position 0xF82

                                 // the name PORTC

                                 // This means that we define a 8 bit

                                 // variable whose value will be stored

                                 // to the memory position F82h

                                 // The memory position F82h is the PORTC

                                 // data register

//Declaration of functions, global variables

void init (void);       //initialization routine

void rb (void);         //interrupt service routine statement (from RB4, RB5, RB6, RB7)

int8 lastPORTB;         //Global variable to hold the last value of PORTΒ

void main(){

     init();            //call the initialization routine

     while (TRUE) {;}   //the main program does nothing

}

//interrupt service routine (change on RB4~RB7)

#INT_RB   

void rb (void){     

   int8 changes;       //Define an 8bit variable

   changes = lastPORTB ^ PORTB;     //The changed bit becomes 1 and appears in the corresponding position in the change variable

   lastPORTB=PORTB;                 //The new PORTB value is transferred to the lastPORTB variable

   if(input(PIN_B0)==1){   

      output_high(PIN_C0);    //alarm is activated

      PORTD=changes;          //The changed bit of PORTB is displayed on PORTD | a LED is on

      delay_ms(6000);         //wait for 6 seconds

      output_low(PIN_C0);     //alarm is de-activated

      PORTD=0x00;             //LED is off

   }

}

//initialization routine    

void init (void){

   set_tris_b(0xff);        // PORTB is defined as input

   set_tris_d(0x00);        // PORTD is defined as output

   set_tris_c(0x00);        // PORTC is defined as output

   enable_interrupts(GLOBAL);    //Enable global interrupts

   enable_interrupts(INT_RB);    //Enable change interrupt by RB4, RB5, RB6, RB7

   PORTD=0x00;                    //The PORTD data register is given the value 0

   PORTC=0x00;                    //The PORTC data register is given the value 0

   lastPORTB=PORTB;               //The new PORTB value is transferred to the lastPORTB variable