this application demo PWM for animation dimmer on screen 7segments
                          common cathode 

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/* MCU              : 16f877A  USED ROM 154 / USED RAM 30    */
/* CLOCK            : 12mhz */
/* compiler         : mikroc 6.2.1 its the best                         */
/* dev              : oshonsoft test bourd   http://www.oshonsoft.com/ */
/* notes            : i have made the same test_bourd its good 

its very cheap 
                      you can do its one hand made 
                      i also test it on boot mode */
                      
//          variables          //
unsigned short  duty=0;
unsigned char dcurr=0;
unsigned char   dimm = 0;
unsigned char digit = 0x10;
unsigned char data[4]={0};
unsigned int range =0;
unsigned char set_step = 0x01;
//       interrupt prototype  //
void interrupt()
{
 
 portb = 0;
 portb = data[dcurr];
 portd = digit ;
  
 digit<<=1;
 dcurr++;
   
 if(dcurr == 4){
          dcurr =0;
          digit= 0x10;
          }
 
    // PWM sofware reclage 
 
if(duty<=dimm)               // 1 to  63 dimmer range
   trisb  = 0x00;
 else trisb = 0xff;
  
   duty++;
   duty &= 0b00111111;
   range++;
   if(range>12)
             {
              set_step++; 
                         
              }
   if(set_step==0x3f)set_step=0x01;
   set_step&=0b00111111 ;
   
 INTCON.T0IF = 0;                // clr flag TMR0IF

}
  // MAIN HERE //
void main()
{
 portb=0;                        // output portd leds anode          
 trisb = 0;
 //==========                    
 portd = 0x10;                   //portd hi nibble scann common cathode
 trisd = 0;

 //=============
 option_reg = 0x80;             // internal clock TMR0 over flow
 
 INTCON  = (1<<GIE) | (1<<T0IE);  // enable interrupt TMR0IE GIE 
 //===========================
 //        print "boot" on 7_segments 1x4       //
 
          data[0] = 0x7C; 
          data[1] = 0x5C;
          data[2] = 0x5C;
          data[3] = 0x70;
          
 while(1){
         
         // to do add your codes here 
           dimm = set_step;
           delay_ms(100);         
          } 
}
// END HERE //
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