#include <16F527.h>
#device ADC=8
#use delay(internal=8000000)

int16 distance;          // Defining variables

// Defining the pins

#define trig pin_c4     // Change as you wish, can use any pin in the MCU
#define echo pin_c5     // Change as you wish, can use any pin in the MCU
#define ALL_OUT 0
#define ALL_IN 0xff

#INT_TIMER0
void timer0_isr()
{
   distance+=0xff;
}

void main()
{

setup_adc(ADC_OFF); 
//set_tris_b( 0x32 );    //PIN 5-INPUT  0b00100000
set_tris_c( 0x32 );

OUTPUT_LOW(PIN_c6);
OUTPUT_LOW(PIN_c7);
 
delay_ms(1000);               // Boot-up delay, for troubleshooting

setup_timer_0(T0_INTERNAL);   // initiating timer

enable_interrupts(GLOBAL);    // enable GLOBAL INTERRUPTS

while(true)
{

output_high(trig);                         // ping the sonar
delay_us(20);                            // sending 20us pulse
output_low(trig);

while(!input(ECHO))                       // wait for high state of echo pin
{}

set_timer0(0);                           // setting timer zero
distance=0;
enable_interrupts(INT_TIMER0);         //ENABLE TIMER0 INTERRUPTS;
while(input(ECHO))                       // Wait for high state of echo pin
{}
disable_interrupts(INT_TIMER0);          // DISABLE t0 INTERRUPTS

distance+=get_timer0();
                           
if(distance<300)
{
OUTPUT_LOW(PIN_c6);
OUTPUT_LOW(PIN_c7);
}

if(distance>299 && distance<500)
{
OUTPUT_HIGH(PIN_c6);
OUTPUT_LOW(PIN_c7);
}

if(distance>499 && distance<600)
{
OUTPUT_LOW(PIN_c6);
OUTPUT_HIGH(PIN_c7);
}

if(distance>600 )
{
OUTPUT_HIGH(PIN_c6);
OUTPUT_HIGH(PIN_c7);
}
                                                                         
delay_ms(1000);

}
}