Analog temperature module on A0, on an Arduino Uno

// Analog temperature module on A0.
//
//   module S -> A0   + -> 5V   - -> GND
//
// The module is a 10k thermistor in a divider with a fixed 10k, so the
// reading falls as it warms. From the reading the sketch finds the
// thermistor's resistance, and the beta equation, 1/T = 1/T0 + ln(R/R0)/B,
// turns that into kelvin.
//
// Drag the module's temperature.

void setup() {
  Serial.begin(9600);
  Serial.println("Mokxi Uno: Thermistor module on A0");
}

void loop() {
  int reading = analogRead(A0);
  float r = 10000.0 * reading / (1023.0 - reading);
  float kelvin = 1.0 / (log(r / 10000.0) / 3950.0 + 1.0 / (25.0 + 273.15));
  Serial.print(kelvin - 273.15);
  Serial.println(" C");
  delay(500);
}