/*
  Arduino Forum
  Topic:        Shift Register Code
  Sub-Category: Programming Questions
  Category:     Using Arduino
  Link:         https://forum.arduino.cc/t/shift-register-code/1142032/9
*/

// Pin definitions
#define SRCLK   13    // Pin connected to SHCP (Shift Register Clock)
#define SER     11    // Pin connected to DS (Serial Input)
#define RCLK    9     // Pin connected to STCP (Storage Register Clock)

// Setup function
void setup() {
  ShiftRegisterInit();  // Initialize shift register
}

// Main loop
void loop() {
  // TODO: Add your desired functionality here
  ShiftRegisterWrite(B10010011);  // Write data to the shift register
}

// Function to initialize shift register pins
void ShiftRegisterInit() {
  pinMode(RCLK, OUTPUT);      // Set RCLK pin as output
  pinMode(SER, OUTPUT);       // Set SER pin as output
  pinMode(SRCLK, OUTPUT);     // Set SRCLK pin as output
  digitalWrite(SRCLK, HIGH);  // Set initial state of SRCLK pin to HIGH
  digitalWrite(RCLK, HIGH);   // Set initial state of RCLK pin to HIGH
}

// Function to write data to the shift register
void ShiftRegisterWrite(uint8_t data) {
  digitalWrite(RCLK, LOW);  // Set RCLK pin to LOW for data input
  for (uint8_t index = 0; index < 8; index++) {
    digitalWrite(SRCLK, LOW);      // Set SRCLK pin to LOW for shifting in the next bit
    digitalWrite(SER, bitRead(data, index));  // Write the current bit to SER pin
    digitalWrite(SRCLK, HIGH);     // Set SRCLK pin to HIGH to shift in the data bit
  }
  digitalWrite(RCLK, HIGH);  // Set RCLK pin to HIGH to latch the data to the output pins
}