Day 13- Frustration with Code!

/*
  Temperature Reading from a MAX6675

Modified By Jason DeFuria, BUSAT <[email protected]> on 7/19/2012

Ryan McLaughlin <[email protected]>
*/

#define SO 12    // MISO
#define CLK 13   // Serial Clock

#define TC_0 11  // CS Pin of MAX6607
int TC_0_calib = 0;  // Calibration compensation value in digital counts (.25˚C)

void setup() {

pinMode(SO, INPUT);
pinMode(CLK, OUTPUT);

pinMode(TC_0, OUTPUT);
digitalWrite(TC_0,HIGH);  // Disable device

Serial.begin(9600);
}

/* Create a function read_temp that returns an unsigned int
   with the temp from the specified pin (if multiple MAX6675).  The
   function will return 9999 if the TC is open.

   Usage: read_temp(int pin, int type, int error)
     pin: the CS pin of the MAX6675
     type: 0 for ˚F, 1 for ˚C
     error: error compensation in digital counts
     samples: number of measurement samples (max:10)
*/
float read_temp(int pin, int type, int error, int samples) {
  float value = 0;
  int error_tc;
  float temp;
  float temp_out;

  for (int i=samples; i>0; i–){
    digitalWrite(pin,LOW); // Enable device

    /* Cycle the clock for dummy bit 15 */
    digitalWrite(CLK,HIGH);
    digitalWrite(CLK,LOW);

    /* Read bits 14-3 from MAX6675 for the Temp
         Loop for each bit reading the value and
         storing the final value in ‘temp’
    */
    for (int i=11; i>=0; i–){
        digitalWrite(CLK,HIGH);  // Set Clock to HIGH
        value += digitalRead(SO) << i;  // Read data and add it to our variable
        digitalWrite(CLK,LOW);  // Set Clock to LOW
    }

    /* Read the TC Input inp to check for TC Errors */
    digitalWrite(CLK,HIGH); // Set Clock to HIGH
    error_tc = digitalRead(SO); // Read data
    digitalWrite(CLK,LOW);  // Set Clock to LOW

    digitalWrite(pin, HIGH); //Disable Device
  }

  value = value/samples;  // Divide the value by the number of samples to get the average

  /*
     Keep in mind that the temp that was just read is on the digital scale
     from 0˚C to 1023.75˚C at a resolution of 2^12.  We now need to convert
     to an actual readable temperature (this drove me nuts until I figured
     this out!).  Now multiply by 0.25.  I tried to avoid float math but
     it is tough to do a good conversion to ˚F.  THe final value is converted
     to an int and returned at x10 power.

   */

  value = value + error;  // Insert the calibration error value

  if(type == 0) {  // Request temp in ˚F
    temp = ((value*0.25) * (9.0/5.0)) + 32.0;  // Convert value to ˚F (ensure proper floats!)
  } else if(type == 1) {  // Request temp in ˚C
    temp = (value*0.25);  // Multiply the value by 25 to get temp in ˚C
  }

  temp_out = temp;  // Send the float to an int (X10) for ease of printing.

  /* Output 9999 if there is a TC error, otherwise return ‘temp’ */
  if(error_tc != 0) { return 9999; } else { return temp_out; }
}

void loop() {

  // Read the temperature and print it to serial
  Serial.print(“Temp F: “);
  Serial.print(read_temp(TC_0,0,TC_0_calib,15));
  Serial.print(“\tTemp C: “);
  Serial.println(read_temp(TC_0,1,TC_0_calib,15));

  delay(250);
}