void setup() {
 init_timer();
  volatile char *ddrb = 0x24;
  *ddrb = 0x02; // set pin 9 as pwm
}

void loop() {
  OCR1A = 1040; // 0 degree (Duty cycle = 2.6 %)
  delay(2000);  

  OCR1A = 2800; // 90 degree (Duty cycle = 7 %)
  delay(2000);

  OCR1A = 4800; // 180 degree (Duty cycle = 12 %)
  delay(2000);
}

void init_timer(){

 volatile char *Timer1_TCCR1A = 0x80;
 volatile char *Timer1_TCCR1B = 0x81;
 volatile short *Timer1_TCNT1 = 0x84;
 volatile short *Timer1_ICR1A = 0x86;
 volatile short *Timer1_OCR1A = 0x88;
 

  *Timer1_TCCR1A = 0x82;
  *Timer1_TCCR1B = 0x1a;
  *Timer1_ICR1A  = 39999;           
}