Conditions being met but the if statement isn't working

Projects Programming
1

I am trying to elicit a response whenever I click a button 5 times under a certain amount of time. Before I get to that, I need to make sure that the conditions work and I am getting the right time. So I am trying to print out the time whenever the conditions are met.

The two conditions are that n == 5 (n increases by 1 whenever I push the button) and that the time is under 15,000. I know that the first condition is being met because the monitor prints out n whenever I press the button. The second condition should also be met because I have timed it myself.

But even when both of these conditions are met, the If statement is not printing out what I want it to print out. Help please.

int ledPin = 13;

int buttonPin = 2;
int buttonState;
int lastButtonState = 0;

int buzzerPin = 9;
int buzzerState;

int n = 0;


unsigned long previous_time = 0;
const int interval = 15000;

void setup()
{
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop()
{ 
  unsigned long current_time = millis();
  unsigned long button_time = current_time - previous_time;
    
  buttonState = digitalRead(buttonPin);
  delay(50);

  if (buttonState == HIGH)
  {
    digitalWrite(ledPin, HIGH);
  }
  else
  {
    digitalWrite(ledPin, LOW);
  }

  if (buttonState != lastButtonState)
  {
    if (buttonState == HIGH)
    {
      n = n + 1;
      Serial.println(n);
      if (n >= 5)
      {
        n = 0;
      //  Serial.println(current_time);
      }
      if (n == 1)
      {
        previous_time = millis();
      //  Serial.println(previous_time);
      }
    }
    lastButtonState = buttonState;
  }
  
  if (n == 5 && button_time <= interval)
  {
    Serial.println(current_time);
  }
}
2

How can n be 5 here if you reset it to zero immediately when it reaches 5 here?

3 
`const int interval = 15000;`

Always use unsigned long for any variables associated with millis() or micros().

4

the way to find the error is:
to printout all details right before the if-condition

Serial.print( F("n:") );
Serial print (n); 

Serial.print( F("  button_time:") );
Serial.print(button_time);

Serial.print( F("  interval:") );
Serial.print(interval);

Serial.print( F(" n ==5:") );
Serial.print(n ==5);

Serial.print( F("   button_time <= interval") );
Serial.print(button_time <= interval);

of course this will take 5 minutes time to write down the code
compare to how long it took to get an answer posted

best regards Stefan

5

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