control RC Micro servo motor using PIC16F877

[annhenry]

Hi,
I want to make a movement of RC Micro servo motor from 0 degree to 90 degree. Then, it will stop for a while and reverse back to 0 degree. I had made the servo motor move forward from 0 degree to 90 degree.But unsuccessfully make a reverse movement from 90 degree to 0 degree. I need a help to check my coding.What should i modify in my coding?I had done a lot of adjustment in the coding.But it still move to 90 degree.

#include <pic.h>                  // using 16F877
                        
//   configuration
//==========================================================================
__CONFIG ( 0x3F32 );           
                                 
#define servo   RB1

#define   MHZ   *1000L            /* number of kHz in a MHz */
#define   KHZ   *1               /* number of kHz in a kHz */

#define   Delay_us(x)   { unsigned char _dcnt; \
           _dcnt = (((x)*(20MHZ))/(24MHZ))|1; \
           while(--_dcnt != 0) \
              continue; \
         _dcnt = (((x)*    (20MHZ))/(24MHZ))|1; \
          while(--_dcnt != 0) \
           continue; }

void _Delay_ms(unsigned char y);    
                           // delay ms
void main(void)

{
  unsigned int i,a;
  TRISB = 0b00000001; // PORTB as Ouput Port(servo motor is RB1)
  PORTB = 0b00000000;  //clear portb
  
  while(1)
  {     
   //for(i=0;i<50;i++)
   //{
      
         servo=1;      //set servo pin low
         Delay_us(150);
         Delay_us(150);
         Delay_us(150);      
         
         servo=0;         //set servo pin high
         _Delay_ms(19);      
         Delay_us(50);     
         _Delay_ms(20); }
}
 
void _Delay_ms(unsigned char y)
{
   unsigned char   i;
   do {
      i = 4;
      do {
         Delay_us(250);
      } while(--i);
   } while(--y);
}

 

[milan.rajik]

Use PWM to drive the Servo.