teeeeeensy

volatile byte state = LOW;

void setup() {
  pinMode(A1, INPUT);
  attachInterrupt(A1, blink, CHANGE);
}

void loop() {
    Serial.println(state);
    if (state = 1)
    {
      Serial.println("tryb 1");
      delay(500);
    }
    else
    {
      Serial.println("tryb 2");
      delay(500);
    }

}

void blink() {
  state = !state;
}