int led_pin = 4;
int pwm_pin = 1;

void setup() 
{
  pinMode(led_pin, OUTPUT);
  pinMode(pwm_pin, OUTPUT);
  //analogWrite(pwm_pin, 127);
  //TCCR0B = TCCR0B & 0b11111000 | 0b001;
  TCCR1 =
            (1<<CTC1) |  //enable pwm
            (1<<PWM1A) | // set source to pck
            (1<<(CS10)) | // clear the pin when match with ocr1x
            (1<<COM1A1);
  GTCCR =   (1<<PWM1B) | (1<<COM1B1);
  OCR1C = 250;
  //TIMSK = (1<<OCIE1A) | (1<<TOIE1);   
  sei();
  OCR1A = 120;
}

void loop() 
{ 
  OCR1C = 150;
  delay(1000);
  OCR1C = 200;
  delay(1000);
  OCR1C = 250;
  delay(1000);
  OCR1C = 100;
  delay(1000);
  
  digitalWrite(led_pin, HIGH);
  delay(500);
  digitalWrite(led_pin, LOW);
  delay(500);
}