Help with a temperature sensing.

/*

* This is based on the "array" example in the basic Arduino library.

* My modification shows how to use the Arduino as a sensitive voltmeter with bargraph display.

* Made by TinselKoala 5Dec2012, released into public domain.

*

* The circuit:

* LEDs  anodes on pins 2 through 13, cathodes all to one 220 R to ground

* Thermistor from plus 5v to potpin, selected resistor from potpin to ground:

* select this resistor to match match thermistor cool value

* Piezo buzzer element from speakerOut pin to ground

*

* OR for voltmeter measurement use Ground as -- input, potpin as ++ input, less than 5 volts max

* put a 10 megohm resistor from ground to potpin for pulldown so circuit doesn't float when disconnected

*

*/

int timer = 30;           // Milliseconds, the higher the number, the slower the sample rate.

int ledPins[] = { 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 };       // an array of pin numbers to which LEDs are attached

int pinCount = 12;           // LED count

int potpin = 14;    // set potpin here

int potvalue = 550, rawpot = 550;

int lowlimit = 550, highlimit = 600; // Sets sensitivity and upper and lower endpoints from the 0-1023 total range

// adjust for your thermistor value using Serial Monitor to see raw values at potpin

int ledvalue = 2;

int speakerOut = 17;

void setup() {

  int thisPin;

  // the array elements are numbered from 0 to (pinCount - 1).

  // use a for loop to initialize each pin as an output:

  for (int thisPin = 0; thisPin < pinCount; thisPin++)  {

    pinMode(ledPins[thisPin], OUTPUT);     

  }

  Serial.begin(57600); // for serial monitor of action, comment out if not needed

}

void loop() {

  potvalue = analogRead(potpin); // read voltage on potpin, assign value from 0 to 1023 (0-5V)

   if(potvalue < lowlimit) potvalue = lowlimit; // low end of voltage range to map

   if(potvalue > highlimit) potvalue = highlimit; // high end of voltage range

    ledvalue = map(potvalue,lowlimit,highlimit,0,11); // map the limit range across the LED numbers

    // turn the LED on:

    digitalWrite(ledPins[ledvalue], HIGH);  

    delay(timer);                 

    // turn the LED off:

    digitalWrite(ledPins[ledvalue], LOW);   

    if (ledvalue == pinCount-1) delay(30); // milliseconds, sets flash rate of high limit indicator LED

   //for (count2=0;count2<8;count2++) {

        if(ledvalue == pinCount-1)  {  

         // for(int n=1;n<200;n++){

          analogWrite(speakerOut,1000);

          delayMicroseconds(10000);

          analogWrite(speakerOut, 0);

          delayMicroseconds(1000);

          digitalWrite(ledPins[ledvalue], HIGH);  

    delay(timer);                 

    // turn the LED off:

    digitalWrite(ledPins[ledvalue], LOW);

    //    }

      }

    // Serial monitor section, ok to comment out if not used

    rawpot = analogRead(potpin);

    Serial.print("Raw potpin value =   ");

    Serial.println(rawpot);

    Serial.print("Mapped to LED level  ");

    Serial.println(ledvalue);

  }