Port and LEDs by BARRAGAN http://barraganstudio.com

Ports are sets of 8 pins which can be used to send data in parallel to devices like printers or displays. This example demonstrates the use of digital ports to turn on 8 LEDs connected to digital port 1, the LEDs will reflect the bit value of each pin, value 0 will be 00000000 or all LEDs turned OFF, value 255 will be 11111111 or all LEDs turned ON.

int port = 1;               // which port will be used
byte value = 0;             // byte will go from 0 to 255

void setup()
{
  portMode(port, OUTPUT);
  Serial.begin(9600);       // use serial to monitor value
}

void loop()
{
  portWrite(port, value);   // writes the value to port 0
  value = value + 1;        // increment the variable
  Serial.println(value, DEC);  // print value to console for monitoring
  delay(200);               // waits for 200 milli seconds
}