void setup() {
  // put your setup code here, to run once:
  pinMode(PA1, INPUT);
  pinMode(PA2, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  float a = 0.00;
  a = analogRead (PA1);
  if (a >= 81.6) {
    digitalWrite(PA7, HIGH);
    digitalWrite(PA6, HIGH);
    for (int b = 0; b <= 30; ++b) {
      digitalWrite(PA2, HIGH);
      delay(1);
      digitalWrite(PA2, LOW);
      delay(19);
      break;
    }

  }

  if (a < 81.6) {
    digitalWrite(PA6, LOW);
    digitalWrite(PA7, HIGH);
    for (int b = 0; b <= 30; ++b) {
      digitalWrite(PA2, HIGH);
      delay(2);
      digitalWrite(PA2, LOW);
      delay(18);
      break;
    }

  }
  delay(1);

}