volatile int sensor_Value = 0;
volatile int output_Value = 0;
const int  ledPin = 9;
void setup(){
  Serial.begin(115200);
  pinMode(A0, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(20, INPUT);
}

void loop(){
  sensor_Value = analogRead(A0);
  output_Value = map(sensor_Value,0,1023,0,255);
  analogWrite(ledPin,output_Value);
  Serial.println(sensor_Value);
  int buttonState = digitalRead(20);
  Serial.println(buttonState);
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
}