byte btn_1 = 3;
bool data_btn1 = 0;
#define ditekan 0
bool hold_btn1 = 0;
int counter = 0;
 
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(btn_1, INPUT);
  Serial.println();
}
 
void loop() {
  // program utama berulang-ulang
  data_btn1 = digitalRead(btn_1);//baca GPIO34
  if (data_btn1 == ditekan) {
    if (hold_btn1 == 0) {
      counter += 1; // ini counter
      Serial.print("counter: ");
      Serial.println(counter);
      hold_btn1 = 1;
    }
  } else {
    hold_btn1 = 0;
  }
}