Dear all,

              I use PIC16F684  to control a multiplexer (HCF4052) for one servo and autopilot program.  Program is working well.But somethime is ok and sometime is not work.When I give servo output,multiplexer is working.Amazing it!
Give me ur light.This is a program for Multiplexer .

#include <16F684.H>
#include <stdlib.h>

#define SWLED PIN_C5
#define MUXa PIN_C1
#define MUXb PIN_C2

#fuses INTRC_IO,NOWDT,NOPROTECT,PUT
#use delay(clock=4000000)

//-----------------Global Variables-----------------
long pulseLength=0;

//--------------------------------------------------

#INT_EXT
void isr()
{
   set_timer1(0);
   while(input(PIN_A2)){

   // if SW interrupt triggers during HW interrupt, prevent bogus pulseLength value
   pulseLength = get_timer1();
  
 }
}

void main(){
            //setup interrupts
            ext_int_edge(L_TO_H);
            setup_timer_0(RTCC_INTERNAL|RTCC_DIV_256); // other param causing interrupt to occur every 20 msec
            setup_timer_1(T1_INTERNAL);
            enable_interrupts(INT_EXT);
            enable_interrupts(GLOBAL);
            port_a_pullups (TRUE);
            //output_high(SWLED); delay_ms(1500);
            //output_low(SWLED); delay_ms(1500);
          
while(1){
           
            if(pulseLength>1500) // pulseLength/(clock/4) is time in us
              {
                output_low(SWLED); // LED off under manual control
                output_low(PIN_C4);
                output_low(MUXa); //Mux control
                output_low(MUXb);
                                 
              }

            else if(pulseLength<1500)
              {
                output_high(SWLED); // LED on under AP
                output_high(PIN_C4);
                output_high(MUXa); //Mux control
                output_high(MUXb);
                                 
              }

         }

   }