int led1 = D2;
int led2 = D11;


void setup() {
    pinMode( led1, OUTPUT );
    pinMode( led2, OUTPUT );
}

void loop() {
    digitalWrite( led1, HIGH );
    digitalWrite( led2, LOW );
    delay( 1000 );
    digitalWrite( led1, LOW );
    digitalWrite( led2, HIGH );
    delay( 1000 );
    
}