// How to put bits into a decimal value.

const int inputPins[] = {4,5,6,7};

void setup() 
{
  Serial.begin(115200);
  Serial.println("Hello, ESP32-C3!");

  for(int i=0; i<4; i++)
    pinMode(inputPins[i],INPUT);
}

void loop() 
{
  int value = 0;
  for(int i=0; i<4; i++)
  {
    int bit = digitalRead(inputPins[i]) == LOW ? 0 : 1;
    bitWrite(value,i,bit);
  }

  Serial.println(value);
  delay(300);
}