#include <SoftwareSerial.h>

SoftwareSerial mySerial(5,6); // RX, TX

int led = 3;
int bt = 2;

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

pinMode(LED, OUTPUT);
pinMode(BTN, INPUT);

}

void loop()
{
  int a = analogRead(BTN);
  mySerial.println("BT value : ");
  mySerial.println(a);
  if (a >= 100)
  {
    digitalWrite(LED,HIGH);
    delay(100);
    digitalWrite(LED,LOW);
    delay(100);
  }
  else
  {
    digitalWrite(LED,LOW);
  }
}