HELP with code for the Assembled Data Logging shield for Arduino

[CASFLisa]

Hello,

I am not that well versed with C++ coding and can't seem to get my code to work. If anyone could help me you would be saving me tons :)!!!!

Ok so I have the following:
- Arduino Uno R3
- Adafruit Universal Thermocouple Amplifier MAX31856 Breakout
-Thermocouple Type-K Glass Braid Insulated - 5m
-Adafruit Assembled Data Logging shield for Arduino
-MPM3610 5V Buck Converter Breakout - 21V In 5V Out at 1.2A

Everything works but the SD card logging, thus I believe my code is way off on how to store the data on a csv file on the sd card.

Here is the code I had prior to adding the data logging shield:

Code: Select all

// Basic example using one-shot measurement.
// The call to readThermocoupleTemperature() is blocking for O(100ms)

#include <Adafruit_MAX31856.h>

// Use software SPI: CS, DI, DO, CLK
Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(4, 5, 6, 7);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(10);

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10);
  Serial.println("MAX31856 thermocouple test");

  maxthermo.begin();

  maxthermo.setThermocoupleType(MAX31856_TCTYPE_K);

  Serial.print("Thermocouple type: ");
  switch (maxthermo.getThermocoupleType() ) {
    case MAX31856_TCTYPE_B: Serial.println("B Type"); break;
    case MAX31856_TCTYPE_E: Serial.println("E Type"); break;
    case MAX31856_TCTYPE_J: Serial.println("J Type"); break;
    case MAX31856_TCTYPE_K: Serial.println("K Type"); break;
    case MAX31856_TCTYPE_N: Serial.println("N Type"); break;
    case MAX31856_TCTYPE_R: Serial.println("R Type"); break;
    case MAX31856_TCTYPE_S: Serial.println("S Type"); break;
    case MAX31856_TCTYPE_T: Serial.println("T Type"); break;
    case MAX31856_VMODE_G8: Serial.println("Voltage x8 Gain mode"); break;
    case MAX31856_VMODE_G32: Serial.println("Voltage x8 Gain mode"); break;
    default: Serial.println("Unknown"); break;
  }
  maxthermo.setTempFaultThreshholds(15, +28); // The call to readThermocoupleTemperature() is blocking for O(100ms)
  maxthermo.setColdJunctionFaultThreshholds(-127, +127);
maxthermo.setConversionMode(MAX31856_CONTINUOUS);
}

void loop() {
  Serial.print("Cold Junction Temp: ");
  Serial.println(maxthermo.readCJTemperature());

  Serial.print("Thermocouple Temp: ");
  Serial.println(maxthermo.readThermocoupleTemperature());
  // Check and print any faults
  uint8_t fault = maxthermo.readFault();
  if (fault) {
    if (fault & MAX31856_FAULT_CJRANGE) Serial.println("Cold Junction Range Fault");
    if (fault & MAX31856_FAULT_TCRANGE) Serial.println("Thermocouple Range Fault");
    if (fault & MAX31856_FAULT_CJHIGH)  Serial.println("Cold Junction High Fault");
    if (fault & MAX31856_FAULT_CJLOW)   Serial.println("Cold Junction Low Fault");
    if (fault & MAX31856_FAULT_TCHIGH)  Serial.println("Thermocouple High Fault");
    if (fault & MAX31856_FAULT_TCLOW)   Serial.println("Thermocouple Low Fault");
    if (fault & MAX31856_FAULT_OVUV)    Serial.println("Over/Under Voltage Fault");
    if (fault & MAX31856_FAULT_OPEN)    Serial.println("Thermocouple Open Fault");
  }
  delay(1000);

Here is the code I have after adding the data logging shield that I cant seem to get to work:

Code: Select all

// Basic example using one-shot measurement.
// The call to readThermocoupleTemperature() is blocking for O(100ms)

#include <Adafruit_MAX31856.h>
#include <SPI.h>
#include <SD.h>
#include "RTClib.h"

// how many milliseconds between grabbing data and logging it. 1000 ms is once a second
#define LOG_INTERVAL  1000 // mills between entries (reduce to take more/faster data)

// how many milliseconds before writing the logged data permanently to disk
// set it to the LOG_INTERVAL to write each time (safest)
// set it to 10*LOG_INTERVAL to write all data every 10 datareads, you could lose up to 
// the last 10 reads if power is lost but it uses less power and is much faster!
#define SYNC_INTERVAL 1000 // mills between calls to flush() - to write data to the card
uint32_t syncTime = 0; // time of last sync()



// Use software SPI: CS, DI, DO, CLK
Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(4, 5, 6, 7);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(10);


//int chipSelect = 4;
float CJTOne;
float TCTOne;

// for the data logging shield, we use digital pin 10 for the SD cs line
const int chipSelect = 10;
// the logging file
File logfile;
void error(char *str)
{
  Serial.print("error: ");
  Serial.println(str);
  
  // red LED indicates error
  digitalWrite(redLEDpin, HIGH);

  while(1);
}
void setup(void)
{
  Serial.begin(9600);
  Serial.println();
  
 //  // use debugging LEDs
 //  pinMode(redLEDpin, OUTPUT);
 //  pinMode(greenLEDpin, OUTPUT);
  

  while (!Serial.available());
#endif //WAIT_TO_START

  // initialize the SD card
  Serial.print("Initializing SD card...");
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(10, OUTPUT);
  
  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    error("Card failed, or not present");
  }
  Serial.println("card initialized.");
  
  // create a new file
  char filename[] = "LOGGER00.CSV";
  for (uint8_t i = 0; i < 100; i++) {
    filename[6] = i/10 + '0';
    filename[7] = i%10 + '0';
    if (! SD.exists(filename)) {
      // only open a new file if it doesn't exist
      logfile = SD.open(filename, FILE_WRITE); 
      break;  // leave the loop!
    }
  }
  
  if (! logfile) {
    error("couldnt create file");
  }
  
  Serial.print("Logging to: ");
  Serial.println(filename);

  // connect to RTC
  Wire.begin();  
  if (!RTC.begin()) {
    logfile.println("RTC failed");
#if ECHO_TO_SERIAL
    Serial.println("RTC failed");
#endif  //ECHO_TO_SERIAL
  }
  

  logfile.println("millis,stamp,datetime,light,temp,vcc");    
#if ECHO_TO_SERIAL
  Serial.println("millis,stamp,datetime,light,temp,vcc");
#endif //ECHO_TO_SERIAL
 
  // If you want to set the aref to something other than 5v
  analogReference(EXTERNAL);
}



void loop(void)
{
  DateTime now;

  // delay for the amount of time we want between readings
  delay((LOG_INTERVAL -1) - (millis() % LOG_INTERVAL));
  
  digitalWrite(greenLEDpin, HIGH);
  
  // log milliseconds since starting
  uint32_t m = millis();
  logfile.print(m);           // milliseconds since start
  logfile.print(", ");    
#if ECHO_TO_SERIAL
  Serial.print(m);         // milliseconds since start
  Serial.print(", ");  
#endif

  // fetch the time
  now = RTC.now();
  // log time
  logfile.print(now.unixtime()); // seconds since 1/1/1970
  logfile.print(", ");
  logfile.print('"');
  logfile.print(now.year(), DEC);
  logfile.print("/");
  logfile.print(now.month(), DEC);
  logfile.print("/");
  logfile.print(now.day(), DEC);
  logfile.print(" ");
  logfile.print(now.hour(), DEC);
  logfile.print(":");
  logfile.print(now.minute(), DEC);
  logfile.print(":");
  logfile.print(now.second(), DEC);
  logfile.print('"');
#if ECHO_TO_SERIAL
  Serial.print(now.unixtime()); // seconds since 1/1/1970
  Serial.print(", ");
  Serial.print('"');
  Serial.print(now.year(), DEC);
  Serial.print("/");
  Serial.print(now.month(), DEC);
  Serial.print("/");
  Serial.print(now.day(), DEC);
  Serial.print(" ");
  Serial.print(now.hour(), DEC);
  Serial.print(":");
  Serial.print(now.minute(), DEC);
  Serial.print(":");
  Serial.print(now.second(), DEC);
  Serial.print('"');
#endif //ECHO_TO_SERIAL

  analogRead(photocellPin);
  delay(10); 
  int photocellReading = analogRead(photocellPin);  
  
  analogRead(tempPin); 
  delay(10);
  int tempReading = analogRead(tempPin);    
  
  // converting that reading to voltage, for 3.3v arduino use 3.3, for 5.0, use 5.0
  float voltage = tempReading * aref_voltage / 1024;  
  float temperatureC = (voltage - 0.5) * 100 ;
  float temperatureF = (temperatureC * 9 / 5) + 32;
  
  logfile.print(", ");    
  logfile.print(photocellReading);
  logfile.print(", ");    
  logfile.print(temperatureF);
#if ECHO_TO_SERIAL
  Serial.print(", ");   
  Serial.print(photocellReading);
  Serial.print(", ");    
  Serial.print(temperatureF);
#endif //ECHO_TO_SERIAL

  // Log the estimated 'VCC' voltage by measuring the internal 1.1v ref
  analogRead(BANDGAPREF); 
  delay(10);
  int refReading = analogRead(BANDGAPREF); 
  float supplyvoltage = (bandgap_voltage * 1024) / refReading; 
  
  logfile.print(", ");
  logfile.print(supplyvoltage);
#if ECHO_TO_SERIAL
  Serial.print(", ");   
  Serial.print(supplyvoltage);
#endif // ECHO_TO_SERIAL

  logfile.println();
#if ECHO_TO_SERIAL
  Serial.println();
#endif // ECHO_TO_SERIAL

  digitalWrite(greenLEDpin, LOW);

  // Now we write data to disk! Don't sync too often - requires 2048 bytes of I/O to SD card
  // which uses a bunch of power and takes time
  if ((millis() - syncTime) < SYNC_INTERVAL) return;
  syncTime = millis();
  
  // blink LED to show we are syncing data to the card & updating FAT!
  digitalWrite(redLEDpin, HIGH);
  logfile.flush();
  digitalWrite(redLEDpin, LOW);
  
}


void setup() {
  Serial.begin(115200);
  //while (!Serial) delay(10);

  Serial.println("MAX31856 thermocouple test");

  maxthermo.begin();
  maxthermo.setThermocoupleType(MAX31856_TCTYPE_K);

  Serial.print("Thermocouple type: ");
  switch (maxthermo.getThermocoupleType() ) {
    case MAX31856_TCTYPE_B: Serial.println("B Type"); break;
    case MAX31856_TCTYPE_E: Serial.println("E Type"); break;
    case MAX31856_TCTYPE_J: Serial.println("J Type"); break;
    case MAX31856_TCTYPE_K: Serial.println("K Type"); break;
    case MAX31856_TCTYPE_N: Serial.println("N Type"); break;
    case MAX31856_TCTYPE_R: Serial.println("R Type"); break;
    case MAX31856_TCTYPE_S: Serial.println("S Type"); break;
    case MAX31856_TCTYPE_T: Serial.println("T Type"); break;
    case MAX31856_VMODE_G8: Serial.println("Voltage x8 Gain mode"); break;
    case MAX31856_VMODE_G32: Serial.println("Voltage x8 Gain mode"); break;
    default: Serial.println("Unknown"); break;
  }
  maxthermo.setTempFaultThreshholds(15, +28); // The call to readThermocoupleTemperature() is blocking for O(100ms)
  maxthermo.setColdJunctionFaultThreshholds(-127, +127);
  maxthermo.setConversionMode(MAX31856_CONTINUOUS);

}

void loop() 
{
  Serial.print("Cold Junction Temp: ");
  Serial.println(maxthermo.readCJTemperature());

  
  Serial.print("Thermocouple Temp:  ");
  Serial.println(maxthermo.readThermocoupleTemperature());
  // Check and print any faults
  uint8_t fault = maxthermo.readFault();
  if (fault) {
    if (fault & MAX31856_FAULT_CJRANGE) Serial.println("Cold Junction Range Fault");
    if (fault & MAX31856_FAULT_TCRANGE) Serial.println("Thermocouple Range Fault");
    if (fault & MAX31856_FAULT_CJHIGH)  Serial.println("Cold Junction High Fault");
    if (fault & MAX31856_FAULT_CJLOW)   Serial.println("Cold Junction Low Fault");
    if (fault & MAX31856_FAULT_TCHIGH)  Serial.println("Thermocouple High Fault");
    if (fault & MAX31856_FAULT_TCLOW)   Serial.println("Thermocouple Low Fault");
    if (fault & MAX31856_FAULT_OVUV)    Serial.println("Over/Under Voltage Fault");
    if (fault & MAX31856_FAULT_OPEN)    Serial.println("Thermocouple Open Fault");
  }
  
  delay(1000);
  
} 

Also worth mentioning when i used the the sd card info and datalogging samples all worked well.

If anyone can help me with this you truly are my hero :)!!!!


Lisa

[Franklin97355]

I noticed you had two setups() in your last code. Did you notice it?

[CASFLisa]

I noticed you had two setups() in your last code. Did you notice it?

Hi, Thank you so much for your quick response on this... I didn't notice that can you tell me what code you are referencing? Also, do you know code I need to add to make the data logger store cvs on the SD card?

[CASFLisa]

I noticed you had two setups() in your last code. Did you notice it?

Ok I see what you mean now. You are referring to the void setup(void) I do see that I am changing and will update.

[CASFLisa]

OK :( I am doing something very wrong :). I moved the bottom set up and placed it in the main set up but get this error

error: #endif without #if
#endif //WAIT_TO_START
^~~~~
Multiple libraries were found for "SD.h"
Used: C:\Users\Lisa\Documents\Arduino\libraries\SD
Not used: C:\Users\Lisa\AppData\Local\Arduino15\libraries\SD
exit status 1

Compilation error: #endif without #if

[Franklin97355]

Repost your new existing code (using the CODE (</>) tags to enclose your code) so I can see what you have changed

[CASFLisa]

Repost your new existing code (using the CODE (</>) tags to enclose your code) so I can see what you have changed

Thank you ok here is the new code...

Code: Select all

// Basic example using one-shot measurement.
// The call to readThermocoupleTemperature() is blocking for O(100ms)

#include <Adafruit_MAX31856.h>
#include <SPI.h>
#include <SD.h>
#include "RTClib.h"

// how many milliseconds between grabbing data and logging it. 1000 ms is once a second
#define LOG_INTERVAL  1000 // mills between entries (reduce to take more/faster data)// A simple data logger for the Arduino analog pins
#define ECHO_TO_SERIAL   1 // echo data to serial port
#define WAIT_TO_START    0 // Wait for serial input in setup()

// how many milliseconds before writing the logged data permanently to disk
// set it to the LOG_INTERVAL to write each time (safest)
// set it to 10*LOG_INTERVAL to write all data every 10 datareads, you could lose up to 
// the last 10 reads if power is lost but it uses less power and is much faster!
#define SYNC_INTERVAL 1000 // mills between calls to flush() - to write data to the card
uint32_t syncTime = 0; // time of last sync()

// Use software SPI: CS, DI, DO, CLK
Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(4, 5, 6, 7);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(10);


//int chipSelect = 4;
float CJTOne;
float TCTOne;

// for the data logging shield, we use digital pin 10 for the SD cs line
const int chipSelect = 10;
// the logging file
File logfile;
void error(char *str)
{
  Serial.print("error: ");
  Serial.println(str);
  
  // red LED indicates error
  digitalWrite(redLEDpin, HIGH);

  while(1);
}
void setup() {
  Serial.begin(115200);
  //while (!Serial) delay(10);

  Serial.println("MAX31856 thermocouple test");

  maxthermo.begin();
  maxthermo.setThermocoupleType(MAX31856_TCTYPE_K);

  Serial.print("Thermocouple type: ");
  switch (maxthermo.getThermocoupleType() ) {
    case MAX31856_TCTYPE_B: Serial.println("B Type"); break;
    case MAX31856_TCTYPE_E: Serial.println("E Type"); break;
    case MAX31856_TCTYPE_J: Serial.println("J Type"); break;
    case MAX31856_TCTYPE_K: Serial.println("K Type"); break;
    case MAX31856_TCTYPE_N: Serial.println("N Type"); break;
    case MAX31856_TCTYPE_R: Serial.println("R Type"); break;
    case MAX31856_TCTYPE_S: Serial.println("S Type"); break;
    case MAX31856_TCTYPE_T: Serial.println("T Type"); break;
    case MAX31856_VMODE_G8: Serial.println("Voltage x8 Gain mode"); break;
    case MAX31856_VMODE_G32: Serial.println("Voltage x8 Gain mode"); break;
    default: Serial.println("Unknown"); break;
  }
  maxthermo.setTempFaultThreshholds(15, +28); // The call to readThermocoupleTemperature() is blocking for O(100ms)
  maxthermo.setColdJunctionFaultThreshholds(-127, +127);
  maxthermo.setConversionMode(MAX31856_CONTINUOUS);

  Serial.begin(9600);
  Serial.println();
  
  
  while (!Serial.available());
  #endif //WAIT_TO_START

  // initialize the SD card
  Serial.print("Initializing SD card...");
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(10, OUTPUT);
  
  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    error("Card failed, or not present");
  }
  Serial.println("card initialized.");
  
  // create a new file
  char filename[] = "LOGGER00.CSV";
  for (uint8_t i = 0; i < 100; i++) {
    filename[6] = i/10 + '0';
    filename[7] = i%10 + '0';
    if (! SD.exists(filename)) {
      // only open a new file if it doesn't exist
      logfile = SD.open(filename, FILE_WRITE); 
      break;  // leave the loop!
    }
  }
  
  if (! logfile) {
    error("couldnt create file");
  }
  
  Serial.print("Logging to: ");
  Serial.println(filename);

  // connect to RTC
  Wire.begin();  
  if (!RTC.begin()) {
    logfile.println("RTC failed");
#if ECHO_TO_SERIAL
    Serial.println("RTC failed");
#endif  //ECHO_TO_SERIAL
  }
  

  logfile.println("millis,stamp,datetime,light,temp,vcc");    
#if ECHO_TO_SERIAL
  Serial.println("millis,stamp,datetime,light,temp,vcc");
#endif //ECHO_TO_SERIAL
 
  // If you want to set the aref to something other than 5v
  analogReference(EXTERNAL);
}



void loop(void)
{
  DateTime now;

  // delay for the amount of time we want between readings
  delay((LOG_INTERVAL -1) - (millis() % LOG_INTERVAL));
  
  digitalWrite(greenLEDpin, HIGH);
  
  // log milliseconds since starting
  uint32_t m = millis();
  logfile.print(m);           // milliseconds since start
  logfile.print(", ");    
#if ECHO_TO_SERIAL
  Serial.print(m);         // milliseconds since start
  Serial.print(", ");  
#endif

  // fetch the time
  now = RTC.now();
  // log time
  logfile.print(now.unixtime()); // seconds since 1/1/1970
  logfile.print(", ");
  logfile.print('"');
  logfile.print(now.year(), DEC);
  logfile.print("/");
  logfile.print(now.month(), DEC);
  logfile.print("/");
  logfile.print(now.day(), DEC);
  logfile.print(" ");
  logfile.print(now.hour(), DEC);
  logfile.print(":");
  logfile.print(now.minute(), DEC);
  logfile.print(":");
  logfile.print(now.second(), DEC);
  logfile.print('"');
#if ECHO_TO_SERIAL
  Serial.print(now.unixtime()); // seconds since 1/1/1970
  Serial.print(", ");
  Serial.print('"');
  Serial.print(now.year(), DEC);
  Serial.print("/");
  Serial.print(now.month(), DEC);
  Serial.print("/");
  Serial.print(now.day(), DEC);
  Serial.print(" ");
  Serial.print(now.hour(), DEC);
  Serial.print(":");
  Serial.print(now.minute(), DEC);
  Serial.print(":");
  Serial.print(now.second(), DEC);
  Serial.print('"');
#endif //ECHO_TO_SERIAL

  analogRead(photocellPin);
  delay(10); 
  int photocellReading = analogRead(photocellPin);  
  
  analogRead(tempPin); 
  delay(10);
  int tempReading = analogRead(tempPin);    
  
  // converting that reading to voltage, for 3.3v arduino use 3.3, for 5.0, use 5.0
  float voltage = tempReading * aref_voltage / 1024;  
  float temperatureC = (voltage - 0.5) * 100 ;
  float temperatureF = (temperatureC * 9 / 5) + 32;
  
  logfile.print(", ");    
  logfile.print(photocellReading);
  logfile.print(", ");    
  logfile.print(temperatureF);
#if ECHO_TO_SERIAL
  Serial.print(", ");   
  Serial.print(photocellReading);
  Serial.print(", ");    
  Serial.print(temperatureF);
#endif //ECHO_TO_SERIAL

  // Log the estimated 'VCC' voltage by measuring the internal 1.1v ref
  analogRead(BANDGAPREF); 
  delay(10);
  int refReading = analogRead(BANDGAPREF); 
  float supplyvoltage = (bandgap_voltage * 1024) / refReading; 
  
  logfile.print(", ");
  logfile.print(supplyvoltage);
#if ECHO_TO_SERIAL
  Serial.print(", ");   
  Serial.print(supplyvoltage);
#endif // ECHO_TO_SERIAL

  logfile.println();
#if ECHO_TO_SERIAL
  Serial.println();
#endif // ECHO_TO_SERIAL

  digitalWrite(greenLEDpin, LOW);

  // Now we write data to disk! Don't sync too often - requires 2048 bytes of I/O to SD card
  // which uses a bunch of power and takes time
  if ((millis() - syncTime) < SYNC_INTERVAL) return;
  syncTime = millis();
  
  // blink LED to show we are syncing data to the card & updating FAT!
  digitalWrite(redLEDpin, HIGH);
  logfile.flush();
  digitalWrite(redLEDpin, LOW);
  
}

void loop() 
{
  Serial.print("Cold Junction Temp: ");
  Serial.println(maxthermo.readCJTemperature());

  
  Serial.print("Thermocouple Temp:  ");
  Serial.println(maxthermo.readThermocoupleTemperature());
  // Check and print any faults
  uint8_t fault = maxthermo.readFault();
  if (fault) {
    if (fault & MAX31856_FAULT_CJRANGE) Serial.println("Cold Junction Range Fault");
    if (fault & MAX31856_FAULT_TCRANGE) Serial.println("Thermocouple Range Fault");
    if (fault & MAX31856_FAULT_CJHIGH)  Serial.println("Cold Junction High Fault");
    if (fault & MAX31856_FAULT_CJLOW)   Serial.println("Cold Junction Low Fault");
    if (fault & MAX31856_FAULT_TCHIGH)  Serial.println("Thermocouple High Fault");
    if (fault & MAX31856_FAULT_TCLOW)   Serial.println("Thermocouple Low Fault");
    if (fault & MAX31856_FAULT_OVUV)    Serial.println("Over/Under Voltage Fault");
    if (fault & MAX31856_FAULT_OPEN)    Serial.println("Thermocouple Open Fault");
  }

  delay(1000); 
} 

[CASFLisa]

OK So I changed the code and here is what I have :). Just wanted to send update.

Code: Select all

#include <Wire.h>
#include <Adafruit_MAX31856.h>
#include <RTClib.h>
#include <SD.h>

// Use software SPI: CS, DI, DO, CLK
Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(4, 5, 6, 7);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(10);

RTC_DS3231 rtc;
const int chipSelect = 10;
File dataFile;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10);
  Serial.println("MAX31856 thermocouple test");

  maxthermo.begin();

  maxthermo.setThermocoupleType(MAX31856_TCTYPE_K);
  
  pinMode(chipSelect, OUTPUT);
  if (!SD.begin(chipSelect)) {
    Serial.println("SD card initialization failed!");
    return;
  }
  Serial.println("SD card initialized successfully.");
  
  DateTime now = rtc.now();
  String filename = "data_";
  filename += now.year();
  filename += now.month() < 10 ? "0" + String(now.month()) : String(now.month());
  filename += now.day() < 10 ? "0" + String(now.day()) : String(now.day());
  filename += now.hour() < 10 ? "0" + String(now.hour()) : String(now.hour());
  filename += now.minute() < 10 ? "0" + String(now.minute()) : String(now.minute());
  filename += now.second() < 10 ? "0" + String(now.second()) : String(now.second());
  filename += ".csv";
  dataFile = SD.open(filename, FILE_WRITE);
  if (dataFile) {
    dataFile.println("Time (s),Temperature (C)");
    dataFile.close();
    Serial.print("File created: ");
    Serial.println(filename);
  }
  else {
    Serial.println("Error creating file.");
  }
}

void loop() {
  // Read the cold junction temperature and print it
  float cjTemp = maxthermo.readCJTemperature();
  Serial.print("Cold Junction Temp: ");
  Serial.println(cjTemp);

  // Read the thermocouple temperature and print it
  float tcTemp = maxthermo.readThermocoupleTemperature();
  Serial.print("Thermocouple Temp:  ");
  Serial.println(tcTemp);

  // Check for faults and print any that are detected
  uint8_t fault = maxthermo.readFault();
  if (fault) {
    if (fault & MAX31856_FAULT_CJRANGE) Serial.println("Cold Junction Range Fault");
    if (fault & MAX31856_FAULT_TCRANGE) Serial.println("Thermocouple Range Fault");
    if (fault & MAX31856_FAULT_CJHIGH)  Serial.println("Cold Junction High Fault");
    if (fault & MAX31856_FAULT_CJLOW)   Serial.println("Cold Junction Low Fault");
    if (fault & MAX31856_FAULT_TCHIGH)  Serial.println("Thermocouple High Fault");
    if (fault & MAX31856_FAULT_TCLOW)   Serial.println("Thermocouple Low Fault");
    if (fault & MAX31856_FAULT_OVUV)    Serial.println("Over/Under Voltage Fault");
    if (fault & MAX31856_FAULT_OPEN)    Serial.println("Thermocouple Open Fault");
  }
 DateTime now = rtc.now();
  float temp = maxthermo.readThermocoupleTemperature();

  Serial.print(now.second());
  Serial.print(",");
  Serial.println(temp);

  if (dataFile) {
    dataFile.print(now.second());
    dataFile.print(",");
    dataFile.println(temp);
    dataFile.flush();
  }
  delay(1000);
}