const int salidaLEDa =  2;      // the number of the LED pin
const int salidaLEDb =  3;      // the number of the LED pin
const int salidaLEDc =  4; 
/*const int salidaLEDd =  5; 
const int salidaLEDe =  6; 
const int salidaLEDf =  7; 
const int salidaLEDg =  8; 
*/
bool estadoLED = 0;

float msAnteriores = 0;

void setup() {
  // put your setup code here, to run once:
pinMode(salidaLEDa, OUTPUT);
pinMode(salidaLEDb, OUTPUT);
pinMode(salidaLEDc, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
float msActuales = millis();
if(msActuales - msAnteriores >=1000){
  msAnteriores = msActuales;
  estadoLED = !estadoLED;
  digitalWrite(salidaLEDa,estadoLED);
  digitalWrite(salidaLEDb,estadoLED);
  digitalWrite(salidaLEDc,estadoLED);
}
}