Hardware interrupt switching

Using Arduino Programming Questions
1

Hi, there people,

This is my first project and also my first time coding. So I'm trying to create a slotcar timer for my dad (I did not know this was a fairly prevalent project), since his timer died. Now I would like to detect if a car makes a jumpstart. My problem is that by using a short minimumtime I will get false positives for new laps. But by creating a long minimum time the car could already cross the line and I would not get the starting time of the car. So my idea was to switch the hardware interrupt funtions with a longer minimum elapsed time once the first crossing was done. But right now I'm a little stuck in the code I created, I simplified it a little and left irrelevant function calls out of it:



// Setup sensors
byte sensorPin1 = 2;
byte sensorPin2 = 3;


// flag for function pointer array
int setFunction1 = 0;
int setFunction2 = 0;

// for handeling the when to increase the function pointer or end script
int raceState1 = 0;
int raceState2 = 0;

// variables needed related to timing
unsigned long contactTime1;
unsigned long contactTime2;
unsigned long contactTime2previous;
unsigned long contactTime1previous;
unsigned long raceStart1; 
}


// function pointer with array of isr functions
void (*functionISR1[])() = {newContactStart1, newContactLap1};
void (*functionISR2[])() = {newContactStart2, newContactLap2};


// first lap contact timer to look for a jumpstart by car 1 and/or 2
void newContactStart1(){
  if (millis() - contactTime1 > jumpstart) {
    contactTime1 = millis() ;
    *****
  }
  else {
    raceState = 5;
    *****
  }
}

void newContactStart2(){
  if (millis() - contactTime2 > jumpstart) {
    contactTime2 = millis() ;
    *****
  }
  else { 
    raceState = 5;
    *****
  }
}

// longer mintime to allow for sensor reset since laps shouldnt be that short.
// ISR funtions 1 and 2 respectively
void newContactLap1() {
  if (millis() - contactTime1 > minTime) {
    contactTime1 = millis();
  }
}

void newContactLap2() {
  if (millis() - contactTime2 > minTime) {
    contactTime2 = millis();
  }
}


void setup() {

// interrupts attached.
attachInterrupt(digitalPinToInterrupt(sensorPin1), functionISR1[setFunction1], FALLING);
attachInterrupt(digitalPinToInterrupt(sensorPin2), functionISR2[setFunction2], FALLING);

}


void loop() {
  if (contactTime1 != contactTime1previous)     //which is based on jumpstart time and if before jumpstart time state =5;
    
    if (raceState1 == 0){
      raceState ++ ; 
      #####
      // so i know the total time of the race for the winner and reset the timer for laps.                                     
      contactTime1previous = raceStart1 = contactTime1 ;
      // Display laps total race etc.
    }
    if (raceState1 == 1){
      // calcultate and display laptime base on previous contactime. take of a lap --
      contactTime1previous = contactTime1 ;
    }
    if (raceState == 5) {
      // end script because of jumpstart, or something else like add a panalty lap or panalty time to total time.
    }
}

// the same for player 2 with all the values 2

Now I think my problem is that updating the function in the functionpointer doesn't update the ISR function am I right? To solve this can I just call a new attachinterrupt on the places specified with "*****"? Am I allowed to do this inside the ISR function to make sure it doesn't keep interrupting before setting the timer to the other interrupt function in the main loop? Or should i do it at the place i specified with "#####" outside of the ISR function?

I would like to use IR sensors in the final setup but I am using buttons right now to test since I wasn't sure i was going to get this to work (like I said first project). I have since ordered the sensors but they haven't arrived yet. is there any other problem I should be wary of when using IR sensors instead of the buttons I now use besides dialing in the minimumtime and jumpstart variable?

Lastly, I don't know if this should be in a different post but would switching to an Arduino nano, because it has 2 cores (if i'm not mistaken), allow me to play music when the race starts and ends?

I hope I stated my problem clearly and anyone can help me out. Thank you in advance for reading.

2

Your program is not quite right. "setup()" has formatting issues. All lines must be terminated with a semi-colon (;). Also, move your attachinterrupt calls inside setup(). You have a line of asterisks (*****) that should not be there. These definitions need to be outside setup():

  // Setup sensors
  byte sensorPin1 = 2;
  byte sensorPin2 = 3;
  // flag for function pointer array
  int setFunction1 = 0;
  int setFunction2 = 0;
  // for handeling the when to increase the function pointer or end script
  int raceState1 = 0;
  int raceState2 = 0;
  // variables needed related to timing
  unsigned long contactTime1;
  unsigned long contactTime2;
  unsigned long contactTime2previous;
  unsigned long contactTime1previous;
  unsigned long raceStart1;
3

Thank you for your time I changed the problems you addressed. These are unfortunately not the problems in my real code, I just got sloppy copy pasting the sections of code needed to explain my problem, my bad. I think I fixed all the issues now.

4

"Auto-format" your code when you make changes. Doing this will show mis-alignment, indicating syntax issues in the code. Very good that you found your errors.