// Pin definitions:
// The 74HC595 uses a type of serial connection called SPI
// (Serial Peripheral Interface) that requires three pins:

int datapin = 2; 
int clockpin = 3;
int latchpin = 4;

// We'll also declare a global variable for the data we're
// sending to the shift register:

byte data = 0;

void send_byte(uint16_t val, uint8_t bits) {
  for(uint8_t i = 0; i < bits; i++) {
    digitalWrite(datapin, val & (1 << i));
    digitalWrite(clockpin, HIGH);
    digitalWrite(clockpin, LOW);
  }
}

void setup()
{
  // Set the three SPI pins to be outputs:

  pinMode(datapin, OUTPUT);
  pinMode(clockpin, OUTPUT);  
  pinMode(latchpin, OUTPUT);

  digitalWrite(clockpin, LOW);
  send_byte(0b010101010, 9);
}


void loop()
{
  uint8_t data = 0b10101010;
}