/*
This is Arduino code for 74HC595 chip code 1/8: Walking light 
Build up to 8 digits Seven-Segment display using 74HC595 Shift Register 
Watch full video instruction on YouTube https://youtu.be/xhPXovgFhso
resource page and wiring diagram https://robojax.com/RTJ394
Written and explained by Ahmad Shamshiri on https://youtube.com/@robojax

original code source:
https://docs.sunfounder.com/projects/3in1-kit-v2/en/latest/basic_project/ar_shiftout_led.html
*/
const int DATA_DS_PIN14    = 10; //Pin connected to DATA_DS_PIN14 of 74HC595 
const int LATCH_STCP_PIN12 = 11;//Pin connected to ST_CP of 74HC595
const int CLOCK_SHCP_PIN11 = 12;//Pin connected to SH_CP of 74HC595 

int datArray[] = {B00000000, B00000001, B00000011, B00000111, B00001111, B00011111, B00111111, B01111111, B11111111};

void setup ()
{
  Serial.begin(9600);
  Serial.println("Code 0: 74HC595 2 digit display driver");
  pinMode(LATCH_STCP_PIN12 ,OUTPUT);
  pinMode(CLOCK_SHCP_PIN11,OUTPUT);
  pinMode(DATA_DS_PIN14,OUTPUT);
}
void loop()
{
  for(int num = 0; num <=8; num++)
  {
    digitalWrite(LATCH_STCP_PIN12 ,LOW); //ground ST_CP and hold low for as long as you are transmitting
    shiftOut(DATA_DS_PIN14,CLOCK_SHCP_PIN11,MSBFIRST,datArray[num]);
    //return the latch pin high to signal the chip that it 
    //no longer needs to listen for information
    digitalWrite(LATCH_STCP_PIN12 ,HIGH); //pull the ST_CP to save the data
    delay(2000); //wait for a second
  }
}