#define LED1 12
#define LED2 11
#define LED3 7
#define LED4 6

unsigned long timestamp1 = 10;
unsigned long timestamp2 = 15;
unsigned long timestamp3 = 25;
unsigned long timestamp4 = 50;
unsigned long lasttime1 = 0;
unsigned long lasttime2 = 0;
unsigned long lasttime3 = 0;
unsigned long lasttime4 = 0;

bool led1_on;
bool led2_on;
bool led3_on;
bool led4_on;


void setup() {
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  
  digitalWrite(LED1, LOW);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);

  led1_on = false;
  led2_on = false;
  led3_on = false;
  led4_on = false;  

  Serial.begin(9600);
}

void loop() {
  if (millis() - lasttime1 >= timestamp1){
    lasttime1 = millis();
    Serial.print("LED1 : ");
    Serial.println(lasttime1);
    if(led1_on){
      digitalWrite(LED1, LOW);
      led1_on = false;
    }
    else{
      digitalWrite(LED1, HIGH);
      led1_on = true;
    }
  }

  if (millis() - lasttime2 >= timestamp2){
    lasttime2 = millis();
    Serial.print("LED2 : ");
    Serial.println(lasttime2);
    if(led2_on){
      digitalWrite(LED2, LOW);
      led2_on = false;
    }
    else{
      digitalWrite(LED2, HIGH);
      led2_on = true;
    }
  }

  if (millis() - lasttime3 >= timestamp3){
    lasttime3 = millis();
    Serial.print("LED3 : ");
    Serial.println(lasttime3);
    if(led3_on){
      digitalWrite(LED3, LOW);
      led3_on = false;
    }
    else{
      digitalWrite(LED3, HIGH);
      led3_on = true;
    }
  }

  if (millis() - lasttime4 >= timestamp4){
    lasttime4 = millis();
    Serial.print("LED4 : ");
    Serial.println(lasttime4);
    if(led4_on){
      digitalWrite(LED4, LOW);
      led4_on = false;
    }
    else{
      digitalWrite(LED4, HIGH);
      led4_on = true;
    }
  }
}