Data logging is a crucial aspect of many electronics projects, allowing for the collection and analysis of data over time. This can be particularly useful in applications such as environmental monitoring, industrial automation, and scientific research. By integrating data logging capabilities into an Arduino project, users can store sensor readings and other data for later analysis. This article will guide you through setting up a simple data logging system using an Arduino, a temperature sensor, and an SD card module. The project will demonstrate how to read data from a sensor and store it on an SD card for future use.

Project: In this project, we will create a data logging system that records temperature readings from a sensor and saves them to an SD card. The objectives are to:

• Read temperature data from a sensor.
• Store the data with a timestamp on an SD card.
• Ensure data integrity and manage the SD card storage effectively.

Components List:

• Arduino Uno (1)
• Temperature Sensor (e.g., LM35) (1)
• SD Card Module (1)
• SD Card (1)
• Breadboard (1)
• Jumper Wires (Several)

Examples:

1. Connecting the Components:

   • Connect the temperature sensor to the Arduino:
     • Vcc to 5V
     • GND to GND
     • Output to A0 (Analog Pin 0)
   • Connect the SD card module to the Arduino:
     • Vcc to 5V
     • GND to GND
     • MISO to Pin 12
     • MOSI to Pin 11
     • SCK to Pin 13
     • CS to Pin 10

2. Arduino Code:

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

const int chipSelect = 10; const int sensorPin = A0;

void setup() { Serial.begin(9600); if (!SD.begin(chipSelect)) { Serial.println("SD card initialization failed!"); return; } Serial.println("SD card is ready to use."); }

void loop() { int sensorValue = analogRead(sensorPin); float temperature = (sensorValue 5.0 100.0) / 1024.0;

File dataFile = SD.open("datalog.txt", FILE_WRITE); if (dataFile) { dataFile.print("Temperature: "); dataFile.print(temperature); dataFile.println(" *C"); dataFile.close(); Serial.println("Data logged."); } else { Serial.println("Error opening datalog.txt"); }

delay(1000); }

**Explanation:**
- **#include <SPI.h>** and **#include <SD.h>**: These libraries are necessary for interfacing with the SD card module.
- **const int chipSelect = 10;**: Defines the chip select pin for the SD card module.
- **const int sensorPin = A0;**: Defines the analog pin connected to the temperature sensor.
- **void setup()**: Initializes serial communication and the SD card.
- **void loop()**: Reads the temperature sensor value, converts it to Celsius, and writes it to the SD card.

**Common Challenges:**
- **SD Card Initialization Failure:** Ensure the SD card is properly formatted (FAT16 or FAT32) and correctly inserted.
- **Incorrect Sensor Readings:** Verify the sensor connections and ensure it is calibrated if necessary.