int sensorPin = 0;    // select the input pin for the potentiometer
int sensorValue = 0;  // variable to store the value coming from the sensor

#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif

void setup()
{
  Serial.begin(9600);
  pinMode(6, OUTPUT);
  sbi(ADCSRA,ADPS2);
  cbi(ADCSRA,ADPS1);
  cbi(ADCSRA,ADPS0);
}

void loop() {
  // read the value from the sensor:
  if(analogRead(sensorPin) > 400)
  {
    PORTD = 0b0000000;
    delay_x(5);
    digitalWrite(6, HIGH);
  }
}

void delay_x(uint32_t millis_delay)
{
  uint16_t micros_now = (uint16_t)micros();

  while (millis_delay > 0) {
    if (((uint16_t)micros() - micros_now) >= 1000) {
      millis_delay--;
      micros_now += 1000;
    }
  }
}