void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

int sensorPin = A0;    // select the input pin for the potentiometer
int ledPin = 13;      // select the pin for the LED
int sensorValue = 0;  // variable to store the value coming from the sensor

void setup() {
  // declare the ledPin as an OUTPUT:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);
  // turn the ledPin on
  digitalWrite(ledPin, HIGH);
  // stop the program for <sensorValue> milliseconds:
  delay(sensorValue);
  // turn the ledPin off:
  digitalWrite(ledPin, LOW);
  // stop the program for for <sensorValue> milliseconds:
  delay(sensorValue);
}

int vr_pin = A0;
int led_pin = 11;
void setup() {
///pinMode(vr_pin,INPUT);   มันเป็นอนาล็อก ไม่ต้องกำหนด
pinMode(led_pin,OUTPUT);    /// มันส่งออกต้องกำหนดเป็น OUTPUT ไม่ใช่ INPUT
   Serial.begin(9600);
}

void loop() {
   int vr = analogRead(vr_pin);
   int vr1 = map(vr,0,1023,0,255);
   analogWrite(led_pin,vr1);  /// analogWrite ไม่ใช่ analoWrite
   Serial.println(vr1);
delay(500);
}