const int PL_165_Pin_01 = 18;  /* PL */
const int CP_165_Pin_02 = 19;  /* CP */
const int Q7_165_Pin_09 = 21;   /* Q7 */

const int numBits = 16;   /* Set to 8 * number of shift registers */

void setup() {
  Serial.begin(115200);
}

void getSample_74HC165(){
    pinMode(Q7_165_Pin_09, INPUT);
    pinMode(CP_165_Pin_02, OUTPUT);
    pinMode(PL_165_Pin_01, OUTPUT);

    digitalWrite(PL_165_Pin_01, LOW);    
    digitalWrite(PL_165_Pin_01, HIGH);
}

void shiftOut_74HC165(){
    digitalWrite(CP_165_Pin_02, LOW);
    digitalWrite(CP_165_Pin_02, HIGH); // Shift out the next bit
}

String getInComingStringFrom74HC165()
{
    String incoming = "";
    // Step 1: Sample

    getSample_74HC165();
    // Step 2: Shift
    for (int i = 0; i < numBits; i++)
    {        
        incoming = incoming + (digitalRead(Q7_165_Pin_09) == HIGH ? "1" : "0");
        shiftOut_74HC165();
    }

    return incoming;
}

int binToDec(String bin)
{
    int l = bin.length();
    int dec = 0;

    for (int i = numBits - 1; i >= 0; i--)
    {
        if (bin.substring(l - i - 1, l - i) == "1")
        {
            dec += pow(2, i);
        }
    }
    return dec;
}

void showIncomingInfo(String incoming)
{
    int value = binToDec(incoming);

    if (    
            // value != 65535 && 
            value != 255 && 
    //         // value != 4351 && 
            value != 0
            )
    {
        // if (value != remainValue)
        // {
        //     remainValue = value;

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

            Serial.print("value: ");
            Serial.println(value);

            // buttonName = returnButtonNameFrom74HC165_16led_16button(getInComingStringFrom74HC165());

            // if (buttonName != "")
            // {
            //     Serial.print("button name: ");
            //     Serial.println(btnName);
            //     Serial.println();
            // }
        // }
    }
}

void loop() {

  showIncomingInfo(getInComingStringFrom74HC165());

  // int value = binToDec(incoming);

  // // Step 1: Sample
  // digitalWrite(latchPin, LOW);
  // digitalWrite(latchPin, HIGH);

  // // Step 2: Shift
  // Serial.print("Bits: ");
  // for (int i = 0; i < numBits; i++) {
  //   int bit = digitalRead(dataPin);
  //   if (bit == HIGH) {
  //     Serial.print("1");
  //   } else {
  //     Serial.print("0");
  //   }
  //   digitalWrite(clockPin, HIGH); // Shift out the next bit
  //   digitalWrite(clockPin, LOW);
  // }

  // Serial.println();
  // delay(100);
}