int knopka = 12;
int led_pin = 8;
int knopka_qiymat;


void setup() {
pinMode(knopka, INPUT_PULLUP);
pinMode(led_pin, OUTPUT);
Serial.begin(9600);

}

void loop() {
 knopka_qiymat = !digitalRead(knopka);
 Serial.println(knopka_qiymat);

 digitalWrite(led_pin, knopka_qiymat);
}