Arduino SD Card Module Project for Beginners: Read & Write Data
Project Overview
This beginner-friendly project demonstrates how to use an SD card module with Arduino to read and write data to an SD card. It covers basic file handling operations like checking file existence, creating a file, writing text to it, and reading data from the file.
Project Goals for Arduino SD Card Module
- Learn how to connect an SD card module to Arduino for reading and writing data.
- Understand file handling operations on an SD card using the SD library.
- Store and retrieve text data from an SD card file.
Required Components for Arduino SD Card Module Project
Here’s a list of components needed to build this project:
| Component | Description | Link |
|---|---|---|
| Arduino Uno | Main microcontroller board | Buy on Amazon |
| SD Card Module | Interface for reading/writing SD cards | Check Availability |
| MicroSD Card (with Adapter) | Stores data | Check Availability |
| Jumper Wires | Connects components to Arduino | Buy on Amazon |
| Breadboard | For prototyping connections | Buy on Amazon |
What is an SD Card Module?
An SD card module is a device used to interface an SD card with a microcontroller like Arduino. It enables data storage and retrieval operations on an SD card, allowing you to save sensor data, logs, and other information for later use.
SD Card Module Pinout Overview
| Pin | Description |
|---|---|
| VCC | Power supply (3.3V or 5V) |
| GND | Ground connection |
| MISO | Master In Slave Out, connected to Arduino's digital pin 12 |
| MOSI | Master Out Slave In, connected to Arduino's digital pin 11 |
| SCK | Clock signal, connected to Arduino's digital pin 13 |
| CS | Chip Select, connected to Arduino's digital pin 10 |
Circuit Connection for SD Card Module with Arduino
Follow these connections to set up the SD card module with Arduino:
| SD Card Module Pin | Arduino Pin | Details |
|---|---|---|
| VCC | 5V | Connect to 5V power supply |
| GND | GND | Ground connection |
| MISO | D12 | SPI communication line |
| MOSI | D11 | SPI communication line |
| SCK | D13 | SPI clock signal |
| CS | D10 | Chip Select for SD card module |
How the Circuit Works
The SD card module is interfaced with Arduino using the SPI protocol. The code checks if an SD card is initialized correctly, creates a file if it doesn't exist, writes text data to the file, and reads it back to verify the content. The data is displayed in the Serial Monitor.
Arduino Code for SD Card Module
This code demonstrates reading and writing to an SD card using an SD card module. Copy and upload this code to your Arduino Uno.
#include
const int chipSelect = 10;
File myFile;
void setup() {
Serial.begin(9600); // Initialize serial communication
while (!Serial); // Wait for Serial Monitor
check_and_create_file();
write_text();
}
void loop() {
// Nothing happens after setup finishes
}
void check_and_create_file() {
Serial.print("Initializing SD card...");
// Check if the SD card is available
if (!SD.begin(chipSelect)) {
Serial.println("Initialization failed!");
while (1);
}
Serial.println("Initialization done.");
if (SD.exists("data_log.txt")) {
Serial.println("data_log.txt exists.");
} else {
Serial.println("data_log.txt doesn't exist.");
Serial.println("Creating data_log.txt...");
myFile = SD.open("data_log.txt", FILE_WRITE);
myFile.close();
if (SD.exists("data_log.txt")) {
Serial.println("data_log.txt created.");
} else {
Serial.println("data_log.txt creation failed.");
}
}
}
void write_text() {
myFile = SD.open("data_log.txt", FILE_WRITE);
if (myFile) {
Serial.print("Writing to data_log.txt...");
myFile.println("Testing 1, 2, 3.");
myFile.close();
Serial.println("done.");
} else {
Serial.println("Error opening data_log.txt");
}
myFile = SD.open("data_log.txt");
if (myFile) {
Serial.println("data_log.txt content:");
while (myFile.available()) {
Serial.write(myFile.read());
}
myFile.close();
} else {
Serial.println("Error opening data_log.txt");
}
}
Steps to Upload Arduino Code
- Connect your Arduino to the computer using a USB cable.
- Open the Arduino IDE and paste the code into a new sketch.
- Select the correct board (e.g., Arduino Uno) and port from the "Tools" menu.
- Click the "Upload" button to transfer the code to the Arduino.
Check Output for SD Card Module
- Open the Serial Monitor (Ctrl + Shift + M) after uploading the code.
- Observe the messages for SD card initialization, file creation, and data writing.
- The content of the "data_log.txt" file will be displayed in the Serial Monitor.
Troubleshooting Tips for SD Card Module
- SD Card Initialization Failed: Ensure proper connections and check if the SD card is formatted correctly (FAT16 or FAT32).
- File Not Created: Verify that the SD card has sufficient space and is not write-protected.
- Data Not Displayed: Check if the data was written correctly and if the file opened successfully.
Suggestions for Beginners
Start by testing the SD card module with basic read and write operations. Once you’re comfortable with file handling, explore data logging from sensors for more complex projects.
Recommended Book for Learning Arduino
Arduino Programming for Absolute Beginners - This book provides easy, step-by-step instructions, making it ideal for beginners who want to learn Arduino programming.
For more Arduino tutorials, visit MechatronicsLab.net, where you’ll find resources on Arduino, ESP8266, ESP32, and Raspberry Pi.
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