#define VOLUME_PIN  A0
#define RED_LED     10
#define GREEN_LED    5

void setup() {
  // LED接続ピン出力設定
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
}

void loop() {
  // 抵抗値読み取り
  int sensorVal = analogRead(VOLUME_PIN);

  // 4ビット分解能でPWM出力
  analogWriteResolution(4);
  analogWrite(RED_LED, map(sensorVal, 0, 1023, 0, 15));

  // 8ビット分解能（デフォルト）でPWM出力
  analogWriteResolution(8);
  analogWrite(GREEN_LED, map(sensorVal, 0, 1023, 0, 255));

  // 時間待ち
  delay(100);
}