const uint8_t COM_PIN = A0;

const uint8_t CONTROL_PINS[] = {3, 4, 5, 6};
const uint8_t LENGTH_OF_CONTROL_PINS = sizeof(CONTROL_PINS) / sizeof(CONTROL_PINS[0]);

const uint8_t NUM_OF_INPUTS = 16;

void setup() {
  Serial.begin(9600);

  for(uint8_t i = 0; i < LENGTH_OF_CONTROL_PINS; i++) {
    pinMode(CONTROL_PINS[i], OUTPUT);
  }
}

uint16_t readMux(int channel) {
  for(uint8_t i = 0; i < LENGTH_OF_CONTROL_PINS; i++) {
    // 2 進数表記の channel の i 桁目を取り出し,
    // CONTROL_PINS[i] に出力
    digitalWrite(CONTROL_PINS[i], (channel >> i & 1));
  }
  delay(10);
  return analogRead(COM_PIN);
}

void loop() {
  // 各入力値を半角スペース区切りで出力
  for(uint8_t i = 0; i < (NUM_OF_INPUTS - 1); i++) {
    Serial.print(readMux(i));
    Serial.print(" ");
  }
  Serial.println(readMux(NUM_OF_INPUTS - 1));

  delay(1000);
}