Problem with external interrupt of ATtiny85

Hello guys, I was very excited as this is my first ATtiny project and first day at forum as well but I ran into problem regarding an external interrupt.
I am trying a simple LED circuit on tinkercad to simulate but it is failing so I'll atach the image of the circuit as well.
I have read the basic information and I know that ATTiny85 has only one external interrupt at pin7 i.e PB2. I have used the attachinterrupt function for activation. But unfortunately the interrupt is not getting detected at all, as I was debugging, no matter how many times I press the button it is not enterrring in ISR. Please do help me with circuit and code. Thank You!

int i_boostButton = 2;
volatile byte vi_boostFlag = LOW;
void setup()
{
  
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, INPUT);
  
  attachInterrupt(i_boostButton, boostedOutput, RISING);
}

void boostedOutput() 
{  									
  
  vi_boostFlag =! vi_boostFlag;
  //vi_boostFlag == HIGH;

}

void loop()
{
 if(digitalRead(4) == HIGH)
  {
  	digitalWrite(1, LOW);
    digitalWrite(0, HIGH);
  }
  
  if(digitalRead(4) == LOW)
  {
  	digitalWrite(0, LOW);
    digitalWrite(1, HIGH);
  }
  
  if(vi_boostFlag == HIGH)
  {
	digitalWrite(0, LOW);
    digitalWrite(1, LOW);
    digitalWrite(3, HIGH);
  }
}

I have read the basic information and I know that ATTiny85 has only one external interrupt at pin7

So, you figured you'd skip the step of defining pin 7 as INPUT. I'm curious why.

so I'll atach the image of the circuit as well.

Today?

Why do you think you need an external interrupt to read a switch state?

Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.

Don´t cross post threads!!

Thank you guys for the warm welcome.
As Paul said, for getting answer I should have asked good question, my bad.
Sorry as the pin is missing cause I was copying fragments of the full code just to present you with the gist.
Let me start all over again.
I am doing an LED lighting program for rooms,with option for small or large room. Toggle switch provides me the selected room by the user. The button provides the option for boosted lighting, as I want the boosted lights to be dimmed again after some time and resume the previously running cycle I want that as an interrupt. that is why I want to use the interrupt.
I am attaching the code again with the declared interrupt pin.

int i_boostButton = 2;
volatile byte vi_boostFlag = LOW;

void setup()
{
  
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, INPUT);
  pinMode(2, INPUT);
  
  attachInterrupt(i_boostButton, boostedOutput, RISING);
 } 

void boostedOutput() 
{  									
  
  //vi_boostFlag =! vi_boostFlag;
  vi_boostFlag = HIGH;

}

void loop()
{  
if(digitalRead(4) == HIGH)
  {
  	digitalWrite(1, LOW);
    digitalWrite(0, HIGH);
  }
  
  if(digitalRead(4) == LOW)
  {
  	digitalWrite(0, LOW);
    digitalWrite(1, HIGH);
  }
  
  if(vi_boostFlag == HIGH)
  {
	digitalWrite(0, LOW);
    digitalWrite(1, LOW);
    digitalWrite(3, HIGH);
    delay(5000);
    digitalWrite(3, LOW);
    vi_boostFlag = LOW;
  }
}

Please do feel free to correct me anywhere but just be a little considerate :smiley: its been just one month as I have started arduino learning. Thank you!

In tinkercad we have to address with PB numbering not with actual pin number. So the arrangement is -

Vcc PB2 PB1 PB0
||||
| |
| |
|) |
| |
|_O ____________ |
| | | |
PB5 PB3 PB4 GND

The button provides the option for boosted lighting, as I want the boosted lights to be dimmed again after some time and resume the previously running cycle I want that as an interrupt. that is why I want to use the interrupt.

All that your ISR is doing now is making note of the fact the the ISR was executed. It is up to loop() to notice that that happened. With the way it does that, it could just as easily read the switch state.

What you would have to do is get rid of the delay() call. The blink without delay example shows how to do something some time after something else happened, without resorting to delay().

Thank you sir that was really helpful. delay() was really making nuisance for my project and this millis() option will surely sort that out.
But I have a doubt, I am getting the input from room size switch after that if room size is small I want to keep two lights ON initially for 10 min and for large room it is somewhat different, initially 4 lights for 10 min and then 2 lights for 10 min. After the initial cycles of 10 and 20 mins of small and large rooms respectively, I want to switch to the blinking mode of lights for both the rooms ( 2 lights only, 1 min ON & 1 in OFF ) and keep in the toggle mode till the power supply is cut.
Whilst this all, I want to keep an eye for that boost button as well. So I am little bit confused here about the implementation without interrupt . I tried and write a code for this project using only millis(), without delay and interrupt to be used, Please do correct me or suggest me if I am missing any alternative and better way.
note- the timings used in the code are in seconds for testing.

// constants won't change. Used here to set a pin number:
const int ledPin_1 = 13;      // the number of the LED pin
const int ledPin_2 = 12;      // the number of the LED pin
const int ledPin_3 = 11;      // the number of the LED pin
const int ledPin_4 = 10;      // the number of the LED pin

const int roomSize = 9;       // the number of switch input pin
const int boostButton = 8;    // the number of boost button pin
const long interval = 1000;   // interval at which to blink / toggle 

// Variables will change:
int ledState = LOW;           // ledState used to set the LED
int initialisation = LOW;     // basic initialisation completion Flag
int initialDone = LOW;        // initial mode completion Flag
int toggleDone = LOW;         // toggle mode completion Flag
int room = LOW;               // save the room size selected

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;        // will store last time LED was updated


void setup() {
  // put your setup code here, to run once:
  pinMode(ledPin_1, OUTPUT);
  pinMode(ledPin_2, OUTPUT);
  pinMode(ledPin_3, OUTPUT);
  pinMode(ledPin_4, OUTPUT);
  pinMode(roomSize, INPUT);
  pinMode(boostButton, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  
  unsigned long currentMillis = millis();

  if(digitalRead(roomSize) == LOW){       
    if(room == HIGH){     // if suddenly room size switch is changed to small room 
      room = LOW;         // then start all over again with initial mode
      initialisation = LOW;
      initialDone = LOW;
      toggleDone = LOW; 
      //currentMillis = 0L;
      //previousMillis = 0L;
      digitalWrite(ledPin_1, LOW);
      digitalWrite(ledPin_2, LOW);
      digitalWrite(ledPin_3, LOW);
      digitalWrite(ledPin_4, LOW);
    }
  }

  if(digitalRead(roomSize) == HIGH){
    if(room == LOW){      // if suddenly room size switch is changed to Large room
      room = HIGH;         // then start all over again with initial mode
      initialisation = LOW;
      initialDone = LOW;
      toggleDone = LOW; 
      //currentMillis = 0L;
      //previousMillis = 0L;
      digitalWrite(ledPin_1, LOW);
      digitalWrite(ledPin_2, LOW);
      digitalWrite(ledPin_3, LOW);
      digitalWrite(ledPin_4, LOW);
    }
  }
    
  if(initialisation == LOW){
    digitalWrite(ledPin_1, HIGH);
    digitalWrite(ledPin_2, HIGH);
    if(digitalRead(roomSize) == HIGH){
       digitalWrite(ledPin_3, HIGH);
       digitalWrite(ledPin_4, HIGH);
    }
    initialisation = HIGH;
  }

  if (currentMillis - previousMillis >= 2500 && toggleDone == LOW) {
       digitalWrite(ledPin_3, LOW);
       digitalWrite(ledPin_4, LOW); 
       if(digitalRead(roomSize) == LOW){
        digitalWrite(ledPin_1, LOW);
        digitalWrite(ledPin_2, LOW);
        initialDone = HIGH;             
       }
  }
  
  if (currentMillis - previousMillis >= 5000 && toggleDone == LOW) {
       digitalWrite(ledPin_1, LOW);
       digitalWrite(ledPin_2, LOW);
       initialDone = HIGH;    
  }

  if (currentMillis - previousMillis >= interval && initialDone == HIGH) {
    // save the last time you blinked the LED
    
    toggleDone = HIGH;      // this will avoid reassigning of values in intial mode
    previousMillis = currentMillis;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }

    // set the LED with the ledState of the variable:
    digitalWrite(ledPin_1, ledState);
    digitalWrite(ledPin_2, ledState);
  }

  if(digitalRead(boostButton) == HIGH){
    digitalWrite(ledPin_1, HIGH);
    digitalWrite(ledPin_2, HIGH);
    digitalWrite(ledPin_3, HIGH);
    digitalWrite(ledPin_4, HIGH);
    delay(5000);        // boosted lights for _ mins
    // here I am stuck as how to send the program back to what it was executing
    digitalWrite(ledPin_1, LOW);
    digitalWrite(ledPin_2, LOW);
    digitalWrite(ledPin_3, LOW);
    digitalWrite(ledPin_4, LOW);
  }
}

Though it is working, I found it very hard while coding as I had to involve every condition and in non overlapping or logically correct way. Can you please explain me why the interrupt code was not working and why I should not use interrupt.
Thank you sir!

Before trying to write any code, think about how YOU would do what you describe, using only the appropriate light switches, a watch, and a pencil and pad of paper.

What do you have to keep track of? Room size? When the lights were turned on? Whether the lights are on or off? The color of the dresses of the pretty girls in the room?

When you know what to keep track of, it's easy to create variables to hold that data. That will also give you a pretty good idea what the various states that the system can be in. The boost button has been pressed. The boost button hasn't been pressed. The lights are on, and the 20 minute clock is running. The 20 minute clock has expired. Make a list of all the states that you can think of. Then, think about what causes a change in state. An obvious one is that the 20 minute clock has run out. Put the states in bubbles on a piece of paper. Draw arrows from one state to another when you decide what the trigger is to get from one state to another. Above the arrow, write down the trigger. Below the arrow, right down what you need to do when the transition occurs. For instance, when the 20 minute clock runs out, you need to turn the lights off. What state will you be in, then?

Once you have your state diagram complete, implementing it in code is far less daunting than it appears now.

Hello,

That was a really good suggestion, I implemented it and it was really helpful.
I am facing a major issue, I have written a code using millis() which was executing properly when I was testing (CHECKING WHETHER IT IS TAKING THE INPUT PROPERLY AND IS IT SHIFTING TO TOGGLE/BLINK MODE) but when the sketch run for the longer time for final testing, it behaved abnormally and it is really unpredictable. I tested it for several times but the unpredictable behavior is same. I am attaching the code below but I should address it first.
The code is of the project where I am taking input from switch viz. LOW and HIGH. If LOW, I want to turn on the light for 30 sec first and after that start toggling, ON and OFF for 10 sec respectively till the power supply is ON. On the other hand for HIGH input, initially turn ON light for 60 sec and then start toggling for 10 sec ON and OFF same as the LOW input. The output light is an AC bulb getting toggled via a relay module.
When I was testing for the HIGH input, it completed its first 60 sec turn ON fine as always and started toggling, which was also previously tested and always work fine. But after 10th switching (in the toggling/blinking) which was at light ON state supposedly for 10 sec , it didn't went OFF for 70 sec which it should have after 10 sec. After that everything worked fine , toggling was again back to normal with 10 sec ON and 10 sec OFF. But same happened again after 25th and 70th switching, it remained ON for 70 sec. at those times as well and the weirdest thing is at some times of these anomalies the relay made its "tucked" sound of switching right after 10 sec but light still remained ON and continued to be ON for 60 sec and hence total 70 sec.
So I checked it for several times and each time it was different, for two times it went wrong after the 31st reading (same 70 sec), but remained perfect for next 100 or so switching. Same is the case for LOW input, it also behaves wrongly sometimes and not getting toggled for 40 sec( 30 sec + 10 sec).
I am really confused, I checked the unsigned long's range but it is fine with range more than 49 days, so why this sudden and random misbehaving is really out of my understanding capability.
Please let me know where have I went wrong in the code and why is this happening. I really want the solution for this problem to understand it thoroughly.

NOTE- RELAY MODULE I AM USING SWITCHES TO NORMALLY-OPEN WHEN GND IS APPLIED AS A SIGNAL. SO TO TURN ON THE LIGHT digitalWrite(ledPin, LOW); IS USED AND TO TURN OFF digitalWrite(ledPin, HIGH); IS USED.

const int ledPin = 8;
const int roomSize = 12;       
const long interval = 10000;  // interval at which to blink / toggle

// Variables will change:
int ledState = LOW;           // ledState used to set the LED
int initialisation = LOW;     // basic initialisation completion Flag
int initialDone = LOW;        // initial mode completion Flag
int toggleDone = LOW;         // toggle mode completion Flag
int room = LOW;               // save the room size selected

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store

unsigned long previousMillis = 0;        // will store last time LED was updated

void setup()
{

  // put your setup code here, to run once:
  pinMode(roomSize, INPUT);
  pinMode(ledPin, OUTPUT);

}

void loop()
{
  // put your main code here, to run repeatedly:

  unsigned long currentMillis = millis();

  if (digitalRead(roomSize) == LOW) {
    if (room == HIGH) {   // if suddenly room size switch is changed to small room
      room = LOW;         // then start all over again with initial mode
      initialisation = LOW;
      initialDone = LOW;
      toggleDone = LOW;
      digitalWrite(ledPin, HIGH); //light is turned OFF
      
    }
  }

  if (digitalRead(roomSize) == HIGH) {
    if (room == LOW) {    // if suddenly room size switch is changed to Large room
      room = HIGH;         // then start all over again with initial mode
      initialisation = LOW;
      initialDone = LOW;
      toggleDone = LOW;
      digitalWrite(ledPin, HIGH); //light is turned OFF
      
    }
  }

  if (initialisation == LOW) {    //light is turned ON......INITIAL MODE
    digitalWrite(ledPin, LOW);
    initialisation = HIGH;
  }

  if (currentMillis - previousMillis >= 30000 && toggleDone == LOW) {
    if (digitalRead(roomSize) == LOW) {
      digitalWrite(ledPin, HIGH);   //light is turned OFF
      initialDone = HIGH;
    }
  }

  if (currentMillis - previousMillis >= 60000 && toggleDone == LOW) {
    if (digitalRead(roomSize) == HIGH) {
      digitalWrite(ledPin, HIGH);   //light is turned OFF
      initialDone = HIGH;
    }
  }

  if (currentMillis - previousMillis >= interval && initialDone == HIGH) {     //TOGGLE MODE
    // save the last time you blinked the LED

    toggleDone = HIGH;      // this will avoid reentering in initial mode
    previousMillis = currentMillis;

    
    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }

    // set the LED with the ledState of the variable:
    digitalWrite(ledPin, ledState);

  }
  
}

I really don't understand using int variables and HIGH and LOW instead of boolean variables and true or false, for a lot of your variables.

Hello,

Sorry about that blunder of datatype, at the time of declaration I was not sure whether to use it as a flag or as something else that is why I declared it in int which I should have changed. Thank you for pointing that out that was really a good think for me to keep in mind for the future coding practices.
However so, I changed the data type to boolean and did the minor changes which I though would have had caused the problem but the problem is still there. When the variables were declared as an int, I found it behaving abnormally on the switching cycles like 10, 25, 32, 64, 71, etc. i.e. each time different cycle was affecting and no specific pattern was traceable. After the boolean data type it switched normally a little longer but behaved abnormally on the 98th switching (I am not sure whether the boolean change reduced the problem’s occurrence and delayed it or it is just a coincidence).
The abnormality is still the same if room size LOW is selected; at the time of abnormality it toggles after 40 sec (30+10) rather than 10 sec and continues toggling normally again; on the other hand in case of HIGH room size, it toggles after 70 sec (60+10) at the time of abnormality rather than 10 sec. The two weird things are, first, whenever it misbehaves, most of the times relay makes its “tuck” sound but the bulb remains ON. secondly, the abnormal behavior only happens when the toggle cycle of bulb ON is happening. It has never stayed OFF for 40 sec (30+10), it only happens in when the bulb is ON and should have gone OFF after 10 sec but goes OFF after 40 sec.
I am really clueless about this and can not point on the part which is making it misbehave. Please help me to solve this problem.

the updated code is,

const int ledPin = 10;
const int roomSize = 12;       // the number of switch input pin
const long interval = 10000;  // interval at which to blink / toggle

// Variables will change:
bool ledState = false;           // ledState used to set the LED
bool initialisation = false;     // basic initialisation completion Flag
bool initialDone = false;        // initial mode completion Flag
bool toggleDone = false;         // toggle mode completion Flag
bool room = false;               // save the room size selected

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store

unsigned long previousMillis = 0;        // will store last time LED was updated

void setup()
{

  // put your setup code here, to run once:
  pinMode(roomSize, INPUT);
  pinMode(ledPin, OUTPUT);

}

void loop()
{
  // put your main code here, to run repeatedly:

  unsigned long currentMillis = millis();

  if (digitalRead(roomSize) == LOW) {
    if (room == true) {   // if suddenly room size switch is changed to small room
      room = false;         // then start all over again with initial mode
      initialisation = false;
      initialDone = false;
      toggleDone = false;
      digitalWrite(ledPin, HIGH);
      previousMillis = currentMillis;
      ledState = false;
    }
  }

  if (digitalRead(roomSize) == HIGH) {
    if (room == false) {    // if suddenly room size switch is changed to Large room
      room = true;         // then start all over again with initial mode
      initialisation = false;
      initialDone = false;
      toggleDone = false;
      digitalWrite(ledPin, HIGH);
      previousMillis = currentMillis;
      ledState = false;
    }
  }

  if (initialisation == false) {
    digitalWrite(ledPin, LOW);
    initialisation = true;
  }

  if (currentMillis - previousMillis >= 30000 && toggleDone == false) {
    if (digitalRead(roomSize) == LOW) {
      digitalWrite(ledPin, HIGH);
      initialDone = true;
    }
  }

  if (currentMillis - previousMillis >= 60000 && toggleDone == false) {
    if (digitalRead(roomSize) == HIGH) {
      digitalWrite(ledPin, HIGH);
      initialDone = HIGH;
    }
  }

  if (currentMillis - previousMillis >= interval && initialDone == true) {
    // save the last time you blinked the LED

    toggleDone = true;      // this will avoid reassigning of values in intial mode
    previousMillis = currentMillis;

    //digitalWrite(ledPin, ledState);
    // if the LED is off turn it on and vice-versa:
    if (ledState == false) {
      ledState = true;
    } else {
      ledState = false;
    }

    // set the LED with the ledState of the variable:
    digitalWrite(ledPin, ledState);

  }
  
}

I am attaching circuit diagram, the relay module I am using in the actual circuit switches to NORMALLY OPEN on the GND signal along with Vcc and GND provided from arduino’s Vcc and GND. As to keep the code same in the circuit simulation I have attached the bulb on NORMALLY OPEN to portray the active low behavior of my relay module. Even the source used in the actual circuit is 230V AC but in simulation it is 9v DC.

Thank you & Kind Regards,
Mahimna