int analogPin= A0;
int raw= 0;
int Vin= 5.0;
float Vout= 0;
float R1= 330;
float R2= 0;
float buffer= 0;
//PWM code
int fanpwm= 9;  // Declare fanpwm to be arduino pin 9
int writeValue; // Use this variable for writing to fanpwm
int rawtemp;
//safety code
int tempMax = 632;   // the maximum temperature before power kill safty
int safety = 13;  // Main relay enable-disable Safety disable (currently TEST led)

void setup()
{
pinMode(fanpwm, OUTPUT); //set fanpwm to be an OUTPUT
pinMode(safety, OUTPUT); //set safety control pin to be an output
Serial.begin(9600);
}

void loop ()

{
raw= analogRead(analogPin);
if(raw)
{
buffer= raw * Vin;
Vout= (buffer)/1024.0;
buffer= (Vin/Vout) -1;
R2= R1 * buffer;
writeValue =  map(raw, 585, 615, 0, 255);
writeValue = constrain(writeValue, 64, 255);

//safety code
   if(raw  > tempMax) {        // if temp is higher than tempMax
     digitalWrite(safety, LOW);  // turn on safety (TURN off main relay and send Estop code)
   } else {                    // else turn on Relay (thumbs up all is good)
     digitalWrite(safety, HIGH);
   }

analogWrite(fanpwm, writeValue);      //Write to the fanpwm control speed by temp
Serial.print("raw = ");
Serial.println(raw);
Serial.print("Vout: ");
Serial.println(Vout);
Serial.print("R2: ");
Serial.println(R2);
Serial.print("writeValue = ");
Serial.println(writeValue);
delay(1000);
}
}