int latchPin = 5;	// Latch pin of 74HC595 is connected to Digital pin 5
int clockPin = 6;	// Clock pin of 74HC595 is connected to Digital pin 6
int dataPin = 4;	// Data pin of 74HC595 is connected to Digital pin 4

byte leds = 0;		// Variable to hold the pattern of which LEDs are currently turned on or off

void setup() 
{
  // Set all the pins of 74HC595 as OUTPUT
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);  
  pinMode(clockPin, OUTPUT);
}

void loop() 
{
  leds = 0;	// Initially turns all the LEDs off, by giving the variable 'leds' the value 0
  updateShiftRegister();
  delay(500);

  for (int i = 0; i < 8; i++)	// Turn all the LEDs ON one by one.
  {
    bitSet(leds, i);		// Set the bit that controls that LED in the variable 'leds'
    updateShiftRegister();
    delay(500);
  }
}

/*
 * updateShiftRegister() - This function sets the latchPin to low, then calls the Arduino function 'shiftOut' to shift out contents of variable 'leds' in the shift register before putting the 'latchPin' high again.
 */
void updateShiftRegister()
{
   digitalWrite(latchPin, LOW);
   shiftOut(dataPin, clockPin, LSBFIRST, leds);
   digitalWrite(latchPin, HIGH);
}

int latchPin = 5;
int clockPin = 6;
int dataPin = 4;

// Variable to hold the pattern of which LEDs are currently turned on or off
byte leds = 0;

void loop() 
{
  leds = 0;
  updateShiftRegister();
  delay(500);

  for (int i = 0; i < 8; i++)
  {
    bitSet(leds, i);
    updateShiftRegister();
    delay(500);
  }
}

void updateShiftRegister()
{
   digitalWrite(latchPin, LOW);
   shiftOut(dataPin, clockPin, LSBFIRST, leds);
   digitalWrite(latchPin, HIGH);
}

int latchPin = 5;		// Latch pin of 74HC595 is connected to Digital pin 5
int clockPin = 6;		// Clock pin of 74HC595 is connected to Digital pin 6
int dataPin = 4;		// Data pin of 74HC595 is connected to Digital pin 4
int outputEnablePin = 3;	// OE pin of 74HC595 is connected to PWM pin 3

byte leds = 0;		// Variable to hold the pattern of which LEDs are currently turned on or off

/*
 * setup() - this function runs once when you turn your Arduino on
 * We initialize the serial connection with the computer
 */
void setup() 
{
  // Set all the pins of 74HC595 as OUTPUT
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);  
  pinMode(clockPin, OUTPUT);
  pinMode(outputEnablePin, OUTPUT); 
}

/*
 * loop() - this function runs over and over again
 */
void loop() 
{
  setBrightness(255);

  leds = 0;		// Initially turns all the LEDs off, by giving the variable 'leds' the value 0
  updateShiftRegister();
  delay(500);

  for (int i = 0; i < 8; i++)	// Turn all the LEDs ON one by one.
  {
    bitSet(leds, i);		// Set the bit that controls that LED in the variable 'leds'
    updateShiftRegister();
    delay(500);
  }
  for (byte b = 255; b > 0; b--)	// Gradually fade all the LEDs back to off
  {
    setBrightness(b);
    delay(50);
  }
}

/*
 * updateShiftRegister() - This function sets the latchPin to low, then calls the Arduino function 'shiftOut' to shift out contents of variable 'leds' in the shift register before putting the 'latchPin' high again.
 */
void updateShiftRegister()
{
   digitalWrite(latchPin, LOW);
   shiftOut(dataPin, clockPin, LSBFIRST, leds);
   digitalWrite(latchPin, HIGH);
}

/*
 * setBrightness() - Generates PWM signal and writes it to OE pin.
 */
void setBrightness(byte brightness) // 0 to 255
{
  analogWrite(outputEnablePin, 255-brightness);
}

shiftOut(dataPin, clockPin, bitOrder, value)

//**************************************************************//
//  Name    : shiftOutCode, Hello World                         //
//  Notes   : Code for using a 74HC595 Shift Register           //
//          : to count from 0 to 255                            //
//****************************************************************

//Pin connected to ST_CP of 74HC595
int latchPin = 8;
//Pin connected to SH_CP of 74HC595
int clockPin = 12;
////Pin connected to DS of 74HC595
int dataPin = 11;

void setup() {
  //set pins to output because they are addressed in the main loop
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
}

void loop() {
  //count up routine
  for (int j = 0; j < 256; j++) {
    //ground latchPin and hold low for as long as you are transmitting
    digitalWrite(latchPin, LOW);

    shiftOut(dataPin, clockPin, LSBFIRST, j);

    //return the latch pin high to signal chip that it
    //no longer needs to listen for information
    digitalWrite(latchPin, HIGH);
    delay(1000);
  }
}

// Do this for MSBFIRST serial
int data = 500;
// shift out highbyte
shiftOut(dataPin, clock, MSBFIRST, (data >> 8));
// shift out lowbyte
shiftOut(dataPin, clock, MSBFIRST, data);

// Or do this for LSBFIRST serial
data = 500;
// shift out lowbyte
shiftOut(dataPin, clock, LSBFIRST, data);
// shift out highbyte
shiftOut(dataPin, clock, LSBFIRST, (data >> 8));

// Demonstration code for 74HC595 8 bit output
int RCLKPin = 3;   // pin 12 on the 74hc595 latch ST_CP
int SRCLKPin = 6;  // pin 11 on the 74hc595 shift register clock – SH_CP
int SERPin = 4;    // pin 14 on the 74hc595 data - DS
unsigned int d;    // Data to be sent to the shift reg.
int dir =0;        // Direction of walking.

void setup() {
  pinMode(RCLKPin, OUTPUT);    // Set 595 control PIN sto output.
  pinMode(SRCLKPin, OUTPUT);
  pinMode(SERPin, OUTPUT);

  d=1;
}

void loop() {

    delay(100);
    digitalWrite(RCLKPin, LOW);//Latch Low 
    shiftOut(SERPin, SRCLKPin, MSBFIRST, 0x00ff & d);//Shift Out
    digitalWrite(RCLKPin, HIGH);//Latch High
    
    if (!dir) d<<=1; else d>>=1; // Shift

    if (d&0x80) dir=1;           // Set direction.
    if (d&0x01) dir=0;
}

 
// Demonstration code for 74HC595 16 bit output
int RCLKPin = 3;   // pin 12 on the 74hc595 latch - nSS
int SRCLKPin = 6;  // pin 11 on the 74hc595 shift register clock - SCK
int SERPin = 4;    // pin 14 on the 74hc595 data - MOSI
unsigned int d;    // Data to be sent to the shift reg.
int dir =0;        // Direction of walking 1.

void setup() {
  pinMode(RCLKPin, OUTPUT);    // Set 595 control PIN sto output.
  pinMode(SRCLKPin, OUTPUT);
  pinMode(SERPin, OUTPUT);

  d=1;
}

void loop() {

    delay(100);
    digitalWrite(RCLKPin, LOW);

    shiftOut(SERPin, SRCLKPin, MSBFIRST, (0xff00 & d)>>8); // shift out high byte
    shiftOut(SERPin, SRCLKPin, MSBFIRST, 0x00ff & d); // shift out low byte

    digitalWrite(RCLKPin, HIGH);

    if (!dir) d<<=1; else d>>=1; // Shift

    if (d&0x8000) dir=1;           // Set direction.
    if (d&0x0001) dir=0;
}

// Demonstration code for 74HC595 16 bit output and 2x7 segment displays
int RCLKPin = 3;   // pin 12 on the 74hc595 latch - nSS
int SRCLKPin = 6;  // pin 11 on the 74hc595 shift register clock - SCK
int SERPin = 4;    // pin 14 on the 74hc595 data - MOSI
unsigned long d;   // Data to be sent to the shift reg.
int dir,num;       // Direction of walking 1, output number.

// Define an array to translate number to 7segment
char segment[10] = { // segment bit pos: dp g f e d c b a
  0x3f, // zero
  0x06, // one
  0x5b, // two
  0x4f, // three
  0x66, // four
  0x6d, // five
  0x7c, // six
  0x07, // seven
  0x7f, // eight
  0x67  // nine
};

void setup() {
  pinMode(RCLKPin, OUTPUT);    // Set 595 control PINs to output.
  pinMode(SRCLKPin, OUTPUT);
  pinMode(SERPin, OUTPUT);

  d=1;
  num = 0;
}

void loop() {
unsigned char lnum,rnum;

    if(num++>99) num=0;
    lnum = num / 10;
    rnum = num % 10;

    digitalWrite(RCLKPin, LOW);

    shiftOut(SERPin, SRCLKPin, MSBFIRST, segment[lnum]);
    shiftOut(SERPin, SRCLKPin, MSBFIRST, segment[rnum]);
    shiftOut(SERPin, SRCLKPin, MSBFIRST, (0xff00 & d)>>8);
    shiftOut(SERPin, SRCLKPin, MSBFIRST, 0x00ff & d);

    digitalWrite(RCLKPin, HIGH);

    if (!dir) d<<=1; else d>>=1; // Shift

    if (d&0x8000) dir=1;           // Set direction.
    if (d&0x1) dir=0;

    delay(200);
}