float r1=10000.0,r2,v=0,tk,tc,tf;
float c1=1.009249522e-03;
float c2=2.378405444e-04;
float c3=2.019202697e-07;
void setup(){
  pinMode(A0,INPUT);
  Serial.begin(9600);
}
void loop(){
  v=analogRead(A0);
  r2=(r1*(1023.0/v)-1.0);
  tf=((1/c1+c2*log(r2)+c3*log(r2)*log(r2)*log(r2)));
  tc=(tf-273.15);
  tf=((tc*9.0)/(5.0+32.0));
  Serial.println(r2);
  Serial.println(tk);
  Serial.println(tc);
  Serial.println(tf);
  delay(2000);

}