void setup() {
  pinMode(2, OUTPUT);
}

void loop() {
  volatile float pf;
  volatile uint16_t pi;
  volatile int16_t adc;

  digitalWrite(2, HIGH);
  //pf= (float)adc * 0.0122 - 2.5;
  pi = (int32_t)adc * 12 - 2500;
  digitalWrite(2, LOW);
  delay(10);
}