#define Btn1_GPIO 35
#define LED1_GPIO 5
void IRAM_ATTR Ext_INT1_ISR()
{
  //Toggle The LED
  digitalWrite(LED1_GPIO, !digitalRead(LED1_GPIO));
}
void setup()
{
  pinMode(LED1_GPIO, OUTPUT);
  pinMode(Btn1_GPIO,INPUT);
  attachInterrupt(Btn1_GPIO,Ext_INT1_ISR, RISING);

}
void loop()
{
  // Do Nothing...
}