void setup()
{
  DDRD = DDRD | B00011100;    // set direction bits for pins 2 to 4 to be OUTPUT, leave others untouched 
  //(xx | 00 == xx)  same as pinMode(pin, OUTPUT) 
  //Port D 0-7 bits map to Digital Pins 0 to 7, but AVOID Serial Pins 0 & 1.
  Serial.begin(9600); //used for debugging / status
} 

void loop()
{ 
  PORTD=PORTD | B00011100; // turn HIGH bits 2-4, bit 0 and 1 are unaffected
  Serial.print("LEDS ON - PORTD in BINary="); // debug to show masking
  Serial.println(PORTD, BIN); // debug to show masking 
  delay (1500);

  PORTD=PORTD & B11100011; // turn LOW bits 2-4  bit 0 and 1 are unaffected
  Serial.print("LEDS OFF - PORTD in BINary="); // debug to show masking
  Serial.println(PORTD, BIN); // debug to show masking 
  delay (1500);
}