Arduino: Port Manipulation

port_manipulation.cpp

// DDRD (R/W) pin direction (0 = INPUT / 1 = OUTPUT)
// PORTD (R/W) pin state (INPUT: 0 = LOW / 1 = HIGH | OUTPUT: 0 = PULL-UP DIACTIVATED / 1 = PULL-UP ACTIVATED)
// PIND (R) pin state (INPUT ONLY: 0 = LOW / 1 = HIGH)

// bit(n)                                 // calculates value of n-th bit (returns: 0 / 1)
// bitRead(byteName, n)                   // gets value of n-th bit of byte (returns: 0 / 1)
// bitSet(byteName, n)                    // sets value of n-th bit of byte to 1
// bitClear(byteName, n)                  // sets value of n-th bit of byte to 0
// bitWrite(byteName, n, val)             // sets value of n-th bit of byte to 0 or 1

// byteName |= bit(1) | bit(0);           // set bits 0 and 1 in a byte
// byteName &= ~bit(1) & ~bit(0);         // clear bits 0 and 1 in a byte
// byteName ^= bit(1) | bit(0);           // toggle bits 0 and 1 in a byte

DDRD = 0x00;                              // set digital pins 0-7 as INPUT
DDRD = 0xFF;                              // set digital pins 0-7 as OUTPUT

DDRD = B11110000;                         // set digital pins 0-3 as INPUT and digital pins 4-7 in as OUTPUT

DDRD &= ~bit(DDD2);                       // set digital pin 2 as INPUT
DDRD &= ~bit(DDD2); PORTD |= bit(PORTD2); // set digital pin 2 as INPUT_PULLUP
DDRD |= bit(DDD2);                        // set digital pin 2 as OUTPUT

PORTD = 0x00;                             // set digital pins 0-7 as LOW
PORTD = 0xFF;                             // set digital pins 0-7 as HIGH

PORTD = B11110000;                        // set digital pins 0-3 as LOW and digital pins 4-7 as HIGH

PORTD &= ~bit(PORTD2);                    // set digital pin 2 as LOW
PORTD |= bit(PORTD2);                     // set digital pin 2 as HIGH

bitRead(PIND, PIND2);                     // read state of digital pin 2 (0 = LOW, 1 = HIGH)

PORTD ^= bit(PORTD2);                     // toggle state of digital pin 2
PORTD ^= bit(PORTD2) | bit(PORTD3);       // toggle state of digital pins 2 & 3

/*
ARDUINO   PORT 
  PIN     NAME
-------   ----  
   0      PD0
   1      PD1
   2      PD2
   3      PD3
   4      PD4
   5      PD5
   6      PD6
   7      PD7
   8      PB0
   9      PB1
  10      PB2
  11      PB3
  12      PB4
  13      PB5
  A0      PC0
  A1      PC1
  A2      PC2
  A3      PC3
  A4      PC4
  A5      PC5 
*/