#define LED_1 2 // pinD2
#define LED_2 4 //pinD4
void setup()
{
pinMode(LED_1, OUTPUT);
pinMode(LED_2),OUTPUT;
}
void loop()
{
digitalWrite(LED_1, HIGH);
digitalWrite(LED_2, HIGH);
delay(1000);
digitalWrite(LED_1, LOW);
delay(1000);
digitalWrite(LED_2, LOW);
delay(1000);
}