/////////////////////////////////////Exercise 1:

int ledPin = D2;
void setup() {
pinMode(ledPin, OUTPUT);
}
void loop() {
digitalWrite(ledPin, HIGH);
delay(3000);
digitalWrite(ledPin, LOW);
delay(3000);
}



//////////////////////////////////////Exercise 2:

int ledPin = D2;
void setup() {
pinMode(ledPin, OUTPUT);
}
void loop() {
for(int i = 0; i < 5; i++){
digitalWrite(ledPin, HIGH);
delay(500);
digitalWrite(ledPin, LOW);
delay(300);
};
delay(3000);
}



////////////////////////////////////////Exercise 3:

int ledPin = D2;
int ledPin2 = D3;

void setup() {
pinMode(ledPin, OUTPUT);
pinMode(ledPin2, OUTPUT);
}

void loop() {  
digitalWrite(ledPin, HIGH);
digitalWrite(ledPin2, LOW);
delay(300);

digitalWrite(ledPin, LOW);
digitalWrite(ledPin2, HIGH);
delay(300);
}