float round1dp(float f)
{
  float f1 = int(f * 10.0f + (signbit(f) ? -0.5f : +0.5f)) / 10.0f;
  //Serial.print(f, 3);
  //Serial.print("\t");
  //Serial.println(f1, 3);
  return f1;
  //return int(f * 10.0f + (signbit(f) ? -0.5f : +0.5f)) / 10.0f;
  //return int(f * 10.0f + (f < 0 ? -0.5f : +0.5f)) / 10.0f;
}

void setup()
{
  Serial.begin(115200);
  float x = 27.64119002;
  float f = round1dp(x);
  Serial.println(f+1);
}

void loop()
{

}