//Constants https://www.aranacorp.com/en/controlling-8-relays-with-esp32-and-shift-register/
//#define number_of_74hc595s 1
#define number_of_74hc595s 4
#define numOfRegisterPins number_of_74hc595s * 8
#define SER_Pin 15
#define RCLK_Pin 2
#define SRCLK_Pin 4

boolean registers [numOfRegisterPins];

void setup(){
Serial.begin(115200);
Serial.println(F("Initialize System"));
pinMode(SER_Pin, OUTPUT);
pinMode(RCLK_Pin, OUTPUT);
pinMode(SRCLK_Pin, OUTPUT);
clearRegisters();
writeRegisters();
delay(500);
}
/*
1 = 2, 6
2 = 1, 2, 3, 4, 5
3 = 1, 2, 3, 5, 6
4 = 0, 2, 3, 6
5 = 0, 1, 3, 5, 6
6 = 0, 1, 3, 4, 5, 6
7 = 1, 2, 6
8 = 0, 1, 2, 3, 4, 5, 6
9 = 0, 1, 2, 3, 5, 6
0 = 0, 1, 2, 4, 5, 6*/
void loop(){
  writeGrpRelay();
  }

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

void writeRegisters(){
  digitalWrite(RCLK_Pin, LOW);
  for(int i = numOfRegisterPins-1; i >=  0; i--){
    digitalWrite(SRCLK_Pin, LOW); int val = registers[i];
    digitalWrite(SER_Pin, val);
    digitalWrite(SRCLK_Pin, HIGH);
    }
  digitalWrite(RCLK_Pin, HIGH);
}

void setRegisterPin(int index,int value){
  registers[index] = value;
}

void writeGrpRelay(){
  for(int i = numOfRegisterPins-1; i >=  0; i--){
    Serial.print(F("Relay "));Serial.print(i);Serial.println(F(" HIGH"));
    setRegisterPin(i, HIGH);
    writeRegisters();
    delay(200);
    Serial.print(F("Relay "));Serial.print(i);Serial.println(F(" LOW"));
    setRegisterPin(i, LOW);
    writeRegisters();
    delay(500);
  }
}