Interrupts on Arduino Pro Mini

Hi,

I'm using interrupts via two push button on Arduino Pro Mini (a clone one) to manage a menu on an oled display.

here is a piece of the code:

every thing works fine whene ther is no (or a small) delay in void loop !!!!

What I'm I doing wrong ???!!!

int buttonSelectPin = 2;
int buttonNavPin = 3;


volatile long debouncing_time = 320; //Debouncing Time in Milliseconds
volatile unsigned long last_micros;


void setup() {


  pinMode(buttonSelectPin, INPUT_PULLUP); // enable internal pull-up resistor
  pinMode(buttonNavPin, INPUT_PULLUP);

//  attachInterrupt(digitalPinToInterrupt(pin), ISR, mode);
  attachInterrupt(digitalPinToInterrupt(buttonSelectPin),selectInterrupt,FALLING);
  attachInterrupt(digitalPinToInterrupt(buttonNavPin),navInterrupt,FALLING);


}


void loop() {

delay(200000);

}


//----------------------------------------------
//  Check if Button Nav was pressed
//----------------------------------------------
void navInterrupt() {
  if((long)(millis() - last_micros) >= debouncing_time)
  {
    last_micros = millis();

    if (pageMenu==2)
    {
      selector++;  
    }
      
    if (selector>4)
    {
      selector = 0;
    }
  }
}



//----------------------------------------------
//  Check if Button Select was pressed
//----------------------------------------------
void selectInterrupt() {
  if((long)(millis() - last_micros) >= debouncing_time)
  {
    last_micros = millis();
    pageMenu++;
    
   if (pageMenu>2)
    {
      pageMenu = 1;
    }
    
  }
}

  last_micros = millis();What is wrong with this picture?

  delay(200000);Do nothing for 200 seconds. Are you expecting the interrupts to actually do anything during this time ?

Also, your sketch has no outputs, so how do you know what it is doing?

When you think you need to use interrupts to read switch states, the correct solution is CTRL-A, CTRL-X and start writing the code over, with NO blocking functions, like delay().

Thank you everyone. I missed up THE function to execute when the PB is pressed...OMG...I think I need a coffee break.

UKHeliBob pointed out the problem. THANK YOU

UKHeliBob:
  delay(200000);Do nothing for 200 seconds. Are you expecting the interrupts to actually do anything during this time ?