How do i convert my delay into millis

Projects Programming
1 
int led = PB4;
int ip = PB2;
int counter = 0;
static int prevState = 4 ;
static int delay_flag = 0;

const uint16_t t1_load = 0;
const uint16_t t1_comp = 62500;

void setup() {
 // put your setup code here, to run once:

 Serial.begin(9600);
 DDRB |= (1 << led); //setting led an output
 DDRB &= ~(1 << ip);//ir sensor as input

 PORTB |= (1 << ip);  //setting 1 thus enabling pull up resistor

 //reset timer control reg A
 TCCR1A = 0;

 //set prescaler of 256
 TCCR1B |= (1 << CS12);
 TCCR1B &= ~(1 << CS11);
 TCCR1B &= ~(1 << CS10);

 //reset timer 1 and set compare values

 TCNT1 = t1_load;
 OCR1A = t1_comp;

 //enable timer compare interrupts
 TIMSK1 = (1 << OCIE1A);

 //enable global interrupts
 sei();

 }

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

 check();

 if(delay_flag == 1){
   PORTB |= (1 << led);
   delay(3000);
   PORTB &= ~(1 << led);
   delay_flag = 0;
   counter = 0;
 }
}

void failsafe(){
 PORTB &= ~(1 << led);
 counter =0 ;
}

//4 not detected(1) 0 detected (0)

void check() {
PORTB &= ~(1 << led);   //led low;

 int currState = (PINB & B00000100);
 Serial.print(currState);
 if (prevState == 0 && currState == 4 )
 {
   PORTB |= (1 << led);
   delay(3000);
   PORTB &= ~(1 << led);
   counter = 0;
  }
  prevState = currState;
}

ISR(TIMER1_COMPA_vect) {
   counter = counter + 1;
   if(counter == 20){
       delay_flag = 1;
       TCNT1 = t1_load;
       
 }
}
2

See the blink without delay example...
File -> Examples -> 02. Digital -> Blink Without Delay

3

i tried using the millis function , but it still isnt working

void check() {
PORTB &= ~(1 << led); //led low;

int currState = (PINB & B00000100);
Serial.print(currState);
if (prevState == 0 && currState == 4 )
{
long currTime = millis();
PORTB |= (1 << led);
if(currTime - prevTime >= interval){
PORTB &= ~(1 << led);
counter = 0;
prevTime = currTime ;
}

}
prevState = currState;
}

4

Please read the sticky at the top of the forum: "Read this before posting a programming question ..."

If you follow the forum guidelines and then ask your question using complete sentences, you are likely to get more guidance.

5

Have a look at how millis() is used to manage timing without blocking in Several Things at a Time.

And see Using millis() for timing. A beginners guide if you need more explanation.

...R

6

Probably because you start with...

 PORTB &= ~(1 << led);   //led low;

If every time you call function check() you turn the led off, what do you think the overall effect on the led is likely to be?

Also this code...

 if (prevState == 0 && currState == 4 )

...seems to be checking for a state change.

If your millis() code is inside that if it is not going to work well. Millis() testing code needs to be where it executes continuously from loop().