int latchPin = 3;
int clockPin = 4;
int dataPin = 2;

int load = 5;
int latchpin2 = 7;
int dataPin2 = 8;
int clkin = 6;

int no_of_pins = 32;
int loop_iter = no_of_pins + 1;
int led_green = 9;

unsigned long out_data[33] = {0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536,
                              131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864,
                              134217728, 268435456, 536870912, 1073741824, 2147483648};
uint16_t  data = 2147483648;   //1110001100101110
byte A = 0;
byte B = 0;
byte C = 0;
byte D = 0;

unsigned long b_map[] = {0};

void setup() {
  Serial.begin(9600);
  // put your setup code here, to run once:
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  
  pinMode(load, OUTPUT);
  pinMode(latchpin2, OUTPUT);
  pinMode(clkin, OUTPUT);
  pinMode(dataPin2, INPUT_PULLUP);

  pinMode(led_green, OUTPUT);
 }

void loop() {

   for(int j = 0; j < loop_iter; j++)
   {
     digitalWrite(latchPin, LOW);
     for (int n = 24; n >= 0; n-=8)
    {
      shiftOut(dataPin, clockPin, MSBFIRST, (data >> n));
    }
     digitalWrite(latchPin, HIGH);


    // Write pulse to load pin
    digitalWrite(load, LOW);
    delayMicroseconds(5);
    digitalWrite(load, HIGH);
    delayMicroseconds(5);  

    unsigned long incoming = 0;
    digitalWrite(clkin, HIGH);
    digitalWrite(latchpin2, LOW);
    // for( int i=0; i<=16; i+=8)
    // {
        A = shiftIn (dataPin2, clkin, LSBFIRST);
        B = shiftIn (dataPin2, clkin, LSBFIRST);
        C = shiftIn (dataPin2, clkin, LSBFIRST);
        D = shiftIn (dataPin2, clkin, LSBFIRST);

        incoming = D;
        incoming = (incoming << 8) | C;
        incoming = (incoming << 8) | B;
        incoming = (incoming << 8) | A;
        //incoming = (uint32_t)(C << 16) | (uint32_t)(B << 8) | (uint32_t)(A);

    //}
    digitalWrite(latchpin2, HIGH);
    // long x1 = (long)incoming1<<8;
    // long x0 = (long)incoming2;
    // incoming = (x1<<8) | (x0);
    //Print to serial monitor
    Serial.print("Sending :");
    Serial.println(data);

    Serial.print("Receving:");
    Serial.println(incoming); 

    delay(200);
   
  }      
}