[PIC] PIR Sensor Interfacing with PIC16F877A Microcontroller

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sbit pir_in at RB7_bit; //PIR module's output pin
sbit led_ind at RD0_bit; //An LED used as indicator
sbit buz_out at RC1_bit; //Buzzer output
 
sbit pir_in_Direction at TRISB7_bit;
sbit led_ind_Direction at TRISD0_bit;
sbit buz_out_Direction at TRISC1_bit;
void init_delay(); //initial delay routine's forword declaration
 
int i; //declare for using with for loops both in main and
//in the delay routine
void main() {
 
pir_in_Direction=1; //as input
led_ind_Direction=0; //as output
buz_out_Direction=0; //as output
 
led_ind=0; //initially off
buz_out=0; //initially off
pir_in=0;
init_delay(); //1 min delay to activate the PIR module
while(1)
{
if(pir_in==1){
buz_out=1;
for( i=0;i<15;i++)       //Buzzer sounds for 15 seconds
{
led_ind=0;
Delay_ms(500);
led_ind=1;
Delay_ms(500);
}
}
else
{
buz_out=0;
led_ind=0;
}
}
}
void init_delay()
{
for(i=0;i<30;i++)
{
  led_ind=1;
Delay_ms(500);
led_ind=0;
Delay_ms(500);
}
led_ind=0;
}