/*
   Arduino code for Individual control over each pin
   Support for 40+ 74HC595 8 bit shift registers
   http://bildr.org/2011/02/74hc595/
*/

#define DATA_PIN  2  // Pin connected to DS of 74HC595
#define LATCH_PIN 42  // Pin connected to STCP of 74HC595
#define CLOCK_PIN 41 // Pin connected to SHCP of 74HC595

// How many of the shift registers
#define NUM_SHIFT_REGS 4

const uint8_t numOfRegisterPins = NUM_SHIFT_REGS * 8;

bool registers[numOfRegisterPins];

void setup() {
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
  clearRegisters();
  writeRegisters();
}

bool toggle = false;

void loop() {
  // for (uint8_t i = 0; i < 32; i++) {
  //  setRegisterPin(i, HIGH);
  //   writeRegisters();
  //   delay(100);
  // }
  //  for (uint8_t i = 0; i < 32; i++) {
  //  setRegisterPin(i, LOW);
  //   writeRegisters();
  //   delay(100);
  // }
  ChannelSelect(0,0);
  delay(1000);
  
}


//piece,选择哪个选择器（每个选择器3位）
//channel，每个选择器组成的3位二进制
void ChannelSelect(int piece,int channel)
{
    int a=channel /4;
    int b=(channel%4)/2;
    int c=(channel%2);
    setRegisterPin(piece*3, c);
    writeRegisters();
    setRegisterPin(piece*3+1, b);
    writeRegisters();
    setRegisterPin(piece*3+2, a);
    writeRegisters();

}

void clearRegisters() {
  // Reset all register pins
  for (int i = numOfRegisterPins - 1; i >= 0; i--) {
    registers[i] = LOW;
  }
}

void setRegisterPin(int index, int value) {
  // Set an individual pin HIGH or LOW
  registers[index] = value;
}

void writeRegisters() {
  // Set and display registers
  digitalWrite(LATCH_PIN, LOW);

  for (int i = numOfRegisterPins - 1; i >= 0; i--) {
    digitalWrite(CLOCK_PIN, LOW);
    digitalWrite(DATA_PIN, registers[i]);
    digitalWrite(CLOCK_PIN, HIGH);
  }

  digitalWrite(LATCH_PIN, HIGH);
}