#define THERMISTOR_PIN 0
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4092
// max adc: 1023

//https://learn.adafruit.com/thermistor/using-a-thermistor
//https://github.com/miguel5612/Arduino-ThermistorLibrary

//Use a basic example.
//Connect the termistor to GND and A0 pin.
//Connect a 4k7 resistor series to VCC.
//Connect a 10Uf into A0 to GND.
//And Have fun, the library works

#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
   {1, 821},
   {54, 252},
   {107, 207},
   {160, 182},
   {213, 165},
   {266, 152},
   {319, 141},
   {372, 131},
   {425, 123},
   {478, 115},
   {531, 107},
   {584, 100},
   {637, 93},
   {690, 86},
   {743, 78},
   {796, 70},
   {849, 60},
   {902, 49},
   {955, 34},
   {1008, 3}
};
void setup()
{
   Serial.begin(9600);
   Serial.println("Starting temperature exerciser.");
}

void loop()
{
   int rawvalue = analogRead(THERMISTOR_PIN);
   int celsius = read_temp();
   int fahrenheit = (((celsius * 9) / 5) + 32);

   Serial.print("Current temp: ");
   Serial.print(celsius);
   Serial.print("C / ");
   Serial.print(fahrenheit);
   Serial.println("F");
   
   Serial.print("Raw value: ");
   Serial.println(rawvalue);
   Serial.println(" ");

   delay(1000);
}

int read_temp()
{
   int rawtemp = analogRead(THERMISTOR_PIN);
   int current_celsius = 0;

   byte i;
   for (i=1; i<NUMTEMPS; i++)
   {
      if (temptable[i][0] > rawtemp)
      {
         int realtemp  = temptable[i-1][1] + (rawtemp - temptable[i-1][0]) * (temptable[i][1] - temptable[i-1][1]) / (temptable[i][0] - temptable[i-1][0]);

         if (realtemp > 255)
            realtemp = 255;

         current_celsius = realtemp;

         break;
      }
   }

   // Overflow: We just clamp to 0 degrees celsius
   if (i == NUMTEMPS)
   current_celsius = 0;

   return current_celsius;
}