Function Millis() Arduino

Question

I would like to make a countdown with arduino. To do this I'm using the millis () function, but I have a problem, I can not reset this. Reading on the internet I read that it is not possible to do this. So how can I find an alternative for this? In practice, when I pressed the button I started the countdown, while if I put it back, I went into the pause mode.

---

void inizio(){
 Serial.println("INIZIO");
 currentMillis1_general = millis();
 total_1 = currentMillis1_general - currentMillis_general;
 Serial.println(total_1);
 buttonState = digitalRead(buttonPin);
 if(buttonState == HIGH){
 step_funzione = 1;
 delay(200);
 }
}
void countdown(){
 Serial.println("COUNTDOWN");
 display.setBrightness(7);
 currentMillis_general = millis();
 total_general = currentMillis_general - total_1;
 if(total_general - previousMillis_general >= interval_general){
 previousMillis_general += interval_general; 
 //previousMillis_general = currentMillis_general;
 m = new_tempo/60;
 s = new_tempo%60;
 new_tempo--;
 }
 display.showNumberDec(m, true,2,0);
 display.showNumberDec(s, true,2,2);
 Serial.println(total_general);
 buttonState = digitalRead(buttonPin);
 if(buttonState == HIGH){
 step_funzione = 0;
 delay(200);
 }
}

• jsotola: think about this ....How do you know when it is time to replace the oil in your car's engine? .... you cannot reset the odometer to zero

Answer 1

A way to accomplish "Reset" is to set your starting value equal to millis() again. To do the equivalent of "Pause", you need a pause counter. When you begin a pause, save millis() to pauseTime. When you resume running again, add millis() - pauseTime to your pauseCounter. Then your interval should not expire until millis() - pauseCounter > Interval).