/*
  Flip the polarity (- => + )& (+ => -)at same time)
  with A4988 Driver  Relay Module Example
*/
#define relay 8

void setup() {
  pinMode(relay, OUTPUT);
  digitalWrite(relay, LOW);

}

void loop() {
//red led
    digitalWrite(relay, HIGH);
    delay(500);

//green led
    digitalWrite(relay, LOW);
    delay(500);


}