DS18B20 SDcard Data Logger with RTC

silas2745 · June 24, 2024, 12:05pm

Hay fellas,
I´ve a problem with my code.
i´m trying to read and to log the temperature datas from the DS18B20.
The serial print isnt the problem, but when i try to log the temperature the serial print says that it isn´t possible to open the txt-file.
When i´m logging the temperature from the DS3231 everything is fine. It doesnt work with the DS18B20.
Is there someone who could help me?
Thanks


//========Set the time for the RealTimeClock (RTC) with Set_RTC_Time.ino first==========

//For the RTC and the SD-Card-Connector
#include <SD.h>
#include <SPI.h>
#include <DS3231.h>

//For the DS18B20
#include <OneWire.h>
#include <DallasTemperature.h>

File myFile;
DS3231  rtc(SDA, SCL);

int pinCS = 53; // Pin 10 on Arduino Uno

//=====DS18B20======
// Data wire from the DS18B20 is plugged into pin 3 on the Arduino
#define ONE_WIRE_BUS 3

// Setup a OneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);

// Pass OneWire reference to Dallas Temperature
DallasTemperature sensors(&oneWire);



void setup() {
    
  Serial.begin(9600);
  pinMode(pinCS, OUTPUT);
  
  // SD Card Initialization
  if (SD.begin())
  {
    Serial.println("SD card is ready to use.");
  } else
  {
    Serial.println("SD card initialization failed");
    return;
  }
  rtc.begin(); 

  //=======DS18B20=======
  pinMode(ONE_WIRE_BUS, OUTPUT);
  sensors.begin(); //Start up the library   
}
void loop() {
  Serial.print(rtc.getDateStr());
  Serial.print(",");
  Serial.print(rtc.getTimeStr());
  Serial.print(",");
  //======DS18B20=========
  sensors.requestTemperatures(); //Call sensor to request the Temperature
  Serial.println(String(sensors.getTempCByIndex(0)) + "°C"); //Output the values on the monitor
 
  myFile = SD.open("test_ds13b20.txt", FILE_WRITE);
  if (myFile) { 
    myFile.print(rtc.getDateStr());
    myFile.print(",");  
    myFile.print(rtc.getTimeStr());
    myFile.print(","); 
    sensors.requestTemperatures(); //Call sensor to request the Temperature   
    myFile.println(String(sensors.getTempCByIndex(0)) + "°C"); //Save the values on the SD-Card
    myFile.close(); // close the file
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening txt-file");
  }
  delay(3000);  //Wait for 3 sec
}

kolaha · June 24, 2024, 12:39pm

//========Set the time for the RealTimeClock (RTC) with Set_RTC_Time.ino first==========

//For the RTC and the SD-Card-Connector
#include <SD.h>
#include <SPI.h>
#include <DS3231.h>

//For the DS18B20
#include <OneWire.h>
#include <DallasTemperature.h>

File myFile;
DS3231  rtc(SDA, SCL);

int pinCS = 53; // Pin 10 on Arduino Uno

//=====DS18B20======
// Data wire from the DS18B20 is plugged into pin 3 on the Arduino
#define ONE_WIRE_BUS 3

// Setup a OneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);

// Pass OneWire reference to Dallas Temperature
DallasTemperature sensors(&oneWire);

void setup() {
   Serial.begin(9600);
  pinMode(pinCS, OUTPUT);
  
  // SD Card Initialization
  if (SD.begin())      Serial.println("SD card is ready to use.");
  else    Serial.println("SD card initialization failed");
    
  rtc.begin(); 

  //=======DS18B20=======
  pinMode(ONE_WIRE_BUS, OUTPUT);
  sensors.begin(); //Start up the library   
}
void loop() {
  Serial.print(rtc.getDateStr());
  Serial.print(",");
  Serial.print(rtc.getTimeStr());
  Serial.print(",");
  //======DS18B20=========
  sensors.requestTemperatures(); //Call sensor to request the Temperature
String DalasTemp=String(sensors.getTempCByIndex(0)) + "°C";
  Serial.println(DalasTemp); //Output the values on the monitor
 
  myFile = SD.open("test_ds13b20.txt", FILE_WRITE);
  if (myFile) { 
    myFile.print(rtc.getDateStr());
    myFile.print(",");  
    myFile.print(rtc.getTimeStr());
    myFile.print(","); 
    myFile.println(DalasTemp); //Save the values on the SD-Card
    myFile.close(); // close the file
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening txt-file");
  }
  delay(3000);  //Wait for 3 sec
}

silas2745 · June 24, 2024, 1:22pm

Im sorry, it´s still not working

ruilviana · June 24, 2024, 2:33pm

Provide the link to the libraries you are using, as it is giving a compilation error when I use my libraries.

kolaha · June 24, 2024, 2:41pm

your SD don't work, at all, not even for DS3231, bc

must be:
SD.begin(pinCS)

//========Set the time for the RealTimeClock (RTC) with Set_RTC_Time.ino first==========

//For the RTC and the SD-Card-Connector
#include <SD.h>
#include <SPI.h>
#include <DS3231.h>

//For the DS18B20
#include <OneWire.h>
#include <DallasTemperature.h>

DS3231  rtc(SDA, SCL);

int pinCS = 53; // Pin 10 on Arduino Uno

//=====DS18B20======
// Data wire from the DS18B20 is plugged into pin 3 on the Arduino
#define ONE_WIRE_BUS 3

// Setup a OneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);

// Pass OneWire reference to Dallas Temperature
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(9600);

  // SD Card Initialization
  if (SD.begin(pinCS))      Serial.println("SD card is ready to use.");
  else    Serial.println("SD card initialization failed");

  rtc.begin();

  //=======DS18B20=======
  pinMode(ONE_WIRE_BUS, OUTPUT);
  sensors.begin(); //Start up the library
}
void loop() {

  //======DS18B20=========
  sensors.requestTemperatures(); //Call sensor to request the Temperature
  char Log[40];
  sprintf(Log, "%s,%s,%.01f°C", rtc.getDateStr(), rtc.getTimeStr(), sensors.getTempCByIndex(0));

  Serial.println(Log); //Output the values on the monitor

  File myFile = SD.open("test_ds13b20.txt", FILE_WRITE);
  if (myFile) {

    myFile.println(Log); //Save the values on the SD-Card
    myFile.close(); // close the file
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening txt-file");
  }
  delay(3000);  //Wait for 3 sec
}

silas2745 · June 24, 2024, 2:52pm

Yea but in this code without the DS18B20 its working and i dont why ...



//Set the time for the RealTimeClock (RTC) with Set_RTC_Time.ino first

#include <SD.h>
#include <SPI.h>
#include <DS3231.h>


File myFile;
DS3231  rtc(SDA, SCL);

int pinCS = 53; // Pin 10 on Arduino Uno

void setup() {
    
  Serial.begin(9600);
  pinMode(pinCS, OUTPUT);
  
  // SD Card Initialization
  if (SD.begin())
  {
    Serial.println("SD card is ready to use.");
  } else
  {
    Serial.println("SD card initialization failed");
    return;
  }
  rtc.begin();    
}
void loop() {
  Serial.print(rtc.getDateStr());
  Serial.print(",");
  Serial.print(rtc.getTimeStr());
  Serial.print(",");
  Serial.println(int(rtc.getTemp()));
 
  myFile = SD.open("test_01.txt", FILE_WRITE);
  if (myFile) { 
    myFile.print(rtc.getDateStr());
    myFile.print(",");  
    myFile.print(rtc.getTimeStr());
    myFile.print(",");    
    myFile.println(int(rtc.getTemp()));
    myFile.close(); // close the file
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening test.txt");
  }
  delay(3000);  //Wait for 3 seconds
}

kolaha · June 24, 2024, 2:53pm

did you open the file on SD ? what contai it?

silas2745 · June 24, 2024, 3:00pm

The file is empty

ruilviana · June 24, 2024, 3:19pm

The file name for SD can only be up to 8 digits long.

silas2745 · June 24, 2024, 3:24pm

Ou, yes thats the solution thank you so much

Do you know how i can send the Arduino to sleep between the sampling (when i increase the time between two samples)?

ruilviana · June 24, 2024, 3:26pm

See the simulated project here.
I added a routine to read and print data recorded on SD cards (readSD()).

//========Set the time for the RealTimeClock (RTC) with Set_RTC_Time.ino first==========
//For the RTC and the SD-Card-Connector
#include <SD.h>
#include <SPI.h>
#include "DS3231.h"
//For the DS18B20
#include <OneWire.h>
#include <DallasTemperature.h>
File myFile;
DS3231  rtc(SDA, SCL);
int pinCS = 53; // Pin 10 on Arduino Uno
//=====DS18B20======
// Data wire from the DS18B20 is plugged into pin 3 on the Arduino
#define ONE_WIRE_BUS 3
// Setup a OneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);
// Pass OneWire reference to Dallas Temperature
DallasTemperature sensors(&oneWire);
//-------------------------------------------------------------
void setup() {
  Serial.begin(9600);
  pinMode(pinCS, OUTPUT);
  if (SD.begin())  {    // SD Card Initialization
    Serial.println("SD card is ready to use.");
  } 
  else  {
    Serial.println("SD card initialization failed");
    return;
  }
  rtc.begin();
  //=======DS18B20=======
  pinMode(ONE_WIRE_BUS, OUTPUT);
  sensors.begin(); //Start up the library
}
//---------------------------------------------------------------
void loop() {
  Serial.print(rtc.getDateStr());
  Serial.print(",");
  Serial.print(rtc.getTimeStr());
  Serial.print(",");
  //======DS18B20=========
  sensors.requestTemperatures(); //Call sensor to request the Temperature
  Serial.println(String(sensors.getTempCByIndex(0)) + "°C"); //Output the values on the monitor
  myFile = SD.open("test_ds.txt", FILE_WRITE);
  if (myFile) {
    myFile.print(rtc.getDateStr());
    myFile.print(",");
    myFile.print(rtc.getTimeStr());
    myFile.print(",");
    sensors.requestTemperatures(); //Call sensor to request the Temperature
    myFile.println(String(sensors.getTempCByIndex(0)) + "°C"); //Save the values on the SD-Card
    myFile.close(); // close the file
  }
  // if the file didn't open, print an error:
  else {
    Serial.println("error opening txt-file");
  }
  delay(3000);  //Wait for 3 sec
  readSD();
}
//----------------------------------------------------------
void readSD() {
  myFile = SD.open("test_ds.txt", O_READ);    //If no exist, create file
  if (myFile) {
    Serial.println("test_ds.txt listing");
    while (myFile.available()) {
      Serial.write(myFile.read());
    }
    myFile.close();
  }
  else {
    Serial.println("error opening test_ds.txt");
  }
}

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DS18B20 SDcard Data Logger with RTC

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