Loop doing 2 times right and then no

[christianevangelista]

Hi, i very don't know why my program is doing the right thing for 2 loop and then it add 65 seconds to "dt". It make no sense.

int bottone1 = 3;
int bottoneStart = 4;
int ledV = 7;
int ledR5 = 13;
int ledR4 = 12;
int ledR3 = 11;
int ledR2 = 10;
int ledR1 = 9;
unsigned int casuale;
int t1 = 0;
float dt = 0;
int i = 0;

void setup() {
  pinMode(bottone1, INPUT);
  pinMode(bottoneStart, INPUT);
  pinMode(ledV, OUTPUT);
  pinMode(ledR1, OUTPUT);
  pinMode(ledR2, OUTPUT);
  pinMode(ledR3, OUTPUT);
  pinMode(ledR4, OUTPUT);
  pinMode(ledR5, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  spegni();
  digitalWrite(ledV,LOW);
  bool START = true;
  bool RUN = true;
  i = 0;
  t1 = 0;
  dt = 0;
  delay(100);
  while(START){
    if(digitalRead(bottoneStart) == HIGH){
      START = false;
      Serial.println("Si comincia!");
      for (i = 0; i < 5; i++){
         digitalWrite(ledV, HIGH);
         delay(100);
         digitalWrite(ledV,LOW);
         delay(100);    
        }    
      delay(10);  
      accendi();
      casuale = random(500, 5000);
      delay(casuale);
      spegni();
      t1 = millis();
       while(RUN){
        if(digitalRead(bottone1) == HIGH){
          RUN = false;
          dt = (millis()-t1) * 0.001;
          }    
        }
      Serial.print("Tempo di reazione: "); 
      Serial.print(dt, 3);
      Serial.println(" Secondi");
      digitalWrite(ledV, HIGH);
      delay(500);
      digitalWrite(ledV, LOW);
    }
  }
}

void accendi(){
      delay(1000);
      digitalWrite(ledR1, HIGH);
      delay(1000);
      digitalWrite(ledR2, HIGH);
      delay(1000);
      digitalWrite(ledR3, HIGH);
      delay(1000);
      digitalWrite(ledR4, HIGH);
      delay(1000);
      digitalWrite(ledR5, HIGH);
}

void spegni(){
      digitalWrite(ledR1, LOW);      
      digitalWrite(ledR2, LOW);      
      digitalWrite(ledR3, LOW);      
      digitalWrite(ledR4, LOW);
      digitalWrite(ledR5, LOW);
}

[J-M-L]

use unsigned long for anything related to time (like t1)

an int can only represent up to 32767 and then will overflow and go negative

[christianevangelista]

Thank you very much! Now it's all ok!

[J-M-L]

have fun!