lcd module sd card reader arduino free sample

There are different models from different suppliers, but they all work in a similar way, using the SPI communication protocol. The module used in this tutorial is the one shown in figure below (front and back view).

This line of code creates a file called data.txt on your SD card. If the data.txt file already exists,  Arduino will open the file instead of creating another one.

Secure Digital, or SD, Cards are used in a variety of applications. You likely have several of them in your electronic devices as they are used in phones, tablets, cameras, and music players.

Anywhere that you need a large amount of inexpensive, non-volatile memory an SD (or microSD) card is a good choice. And, as you are about to see, these cards are very easy to use in your Arduino projects.

The SD card was developed as a joint effort between SanDisk, Panasonic, and Toshiba. The first SD cards were released in August 1999. In January 2000 the three companies formed theSD Associationto create standards for SD cards.

There are actually three sizes of SD cards – standard SD cards, miniSD cards, and microSD cards. The miniSD card was never that popular and hasn’t been produced since 2008 so modern devices make use of either standard SD cards or microSD cards.

There are also a number of designations on SD cards such as “SDXC”, SDUC”, “UHS-I”, “Class 10” etc. This can get a bit confusing when trying to choose an SD card.

SD Cards have evolved to use different file systems, different speeds, and different connection methods than the original 1999 design.  These differences are designated into five different storage classes:

SD cards are serial data cards and thus have limits to the speed that they can transfer data. As SD cards evolved so has their speeds and there are new designations to determine which cards are faster than others.

Older cards used a Class designation from 1 to 10, with a 10 being the fastest. Modern SD cards can all exceed Class 10 speed so the class designation is virtually meaningless.

A standard SD card uses the SPI bus and works at 3.3 volts.  SDHC and SDXC cards can also switch to the “one-bit SD bus” and in this mode they work on 1.8 volts.

When an SDHC or SDXC card is inserted into its socket it will initially use the SPI bus. The host computer can switch the device to one-bit mode if the device supports it.

SD cards and microSD cards are electrically compatible, however, they do not use the same pinouts. The plastic “SD Adapter” that is usually included with microSD cards is wired to reconfigure the pinout so the microSD card can also be used in an SD card slot.

There are many SD card modules available for the Arduino.  Some of them are stand-alone, others are shields. Many of the shields also have additional components like real time clocks, Ethernet adapters and temperature sensors integrated along with the SD card holder.

The SD card uses 3.3-volt logic so there is a built-in voltage regulator to reduce the 5-volt supply to 3.3-volts. If you use a 3.3-volt supply the regulator is bypassed.

One thing to note is that many of these modules do not have logic-level converters and therefore expect that 3.3-volt logic will be used. If you are using 5-volt logic, as with an Arduino Uno or Mega, you’ll need to supply logic-level converters or use a resistor array to work with the 3.3-volt logic.

These modules are made to be used with 5-volt logic as they contain built-in logic converters, as well as voltage regulators. As such they have only a 5-volt power input.

I’ll be showing you the connections using a microSD module but they are pretty well identical for a full-sized SD module. Remember though that if you elect to use a full-sized module you may need to do some logic-level conversion, otherwise your data will be garbled.

If you are using a shield with an SD or microSD card you might need to change the Chip Select (CS) pin connection, the one I have connected to pin 4. Some shields use pin 6 or pin 10, check with your shield manufacturer or use a multimeter to determine if this is the case with your shield

The Arduino IDE already has alibrary for working with SD cards. It supports both FAT16 and FAT32 file systems on both standard SD (SDSC) or SDHC cards.  Keep that in mind if you are reformatting your microSD card and don’t use exFAT.

You can access these libraries by opening theFilemenu and selectingExamples. From the sub-menu scroll down until you get to theSDentry and highlight that. You’ll see six example sketches that you can try.

In the Setup we set the speed for the serial monitor and then write “Initializing SD card…” to it.  We then initialize the SD card and print an error message if it fails.

Note the line withSD.begin(4)in it. The number “4” is the pin that the Chip Select (CS) of the module is connected to. If you’re using a shield which uses a different pin you’ll need to change this line to the proper value.

TheSD.openopens the file. We specify the file name and then we add theFILE_WRITEparameter to indicate that we want to write to the file.  If we hadn’t specified that the file would be open to read instead.

Compile the sketch and send it to your Arduino, make sure that you have a microSD card in your module and that it is formatted with the FAT32 file system.  Then open your serial monitor.

Try pressing the reset button on your Arduino and observe the serial monitor. You should see an additional line of text every time you press the button. This is because the sketch is appending the text to the file every time it is run.

The SD library has a simple Datalogger example. Unlike a professional datalogger, this one does not use a real time clock to add a timestamp to the data, it simply reads the data and writes it to a file on the SD card.

The wiper of each potentiometer is connected to one of the Arduino analog input pins, A0, A1, and A2. One side of each pot is connected to the 5-volt output, the other side is connected to ground.

This will allow you to vary the voltage sent to the analog pins from zero to 5 volts.  We will measure the voltage and write the value, from 0 to 1023, to the SD card. The results will be saved in a comma-delimited file.

The Datalogger sketch starts off in a similar fashion to the previous example. You’ll note that a constant namedchipSelectis assigned to the pin you are using to connect to the CD line on your module. Again, if you are using a shield that connects CS to a different pin you’ll need to adjust that accordingly.

Load the sketch to your Arduino and open your serial monitor. You will see the values of the three analog inputs displayed, adjust some of the potentiometers and observe how they change.

After running it for a while power down the Arduino and remove the card. Now insert the card into your computer and read the resulting file. You should see it contains the same data you observed on the serial monitor.

Reading the file on your computer is useful but not as convenient as using the Arduino to do it. The final example we will take a look at will read the file to the Arduino serial monitor.

The DumpFile sketch dumps the contents of the file on the SD card to the serial monitor. As with the first example it works entirely in the Setup routine so there is no code in the loop.

You will also need a servo motor, along with a power supply for that motor. Although you could hook the servo up to the Arduino 5-volt output I really don’t recommend it, as sharing a servo with the Arduino power supply isn’t a very good idea – it can induce noise and voltage drops onto the supply lines.

I’ve created two sketches, one that records the servo data onto the SD card and a second one that plays it back. You could expand upon them and include them both in the same sketch, perhaps with some record and playback pushbuttons.

The sketch starts by including libraries for the SPI bus, the SD card module and for the servo motor. All three libraries are part of your Arduino IDE so you don’t need to install anything.

As you can see it is very simple to incorporate SD cards and microSD cards into your Arduino designs. By using them you can add a huge amount of non-volatile storage to your projects.

SD and microSD cards are a simple way to add huge amounts of non-volatile storage to your Arduino designs. In this article, I will show you how to use SD card modules with the Arduino. I will also show you how to record and playback the motion of a servo motor.

Description: The Arduino Graphic LCD (GLCD) screen is a backlit TFT LCD screen with headers. You can draw text, images, and shapes to the screen with the GLCD library. There is an onboard micro-SD card slot on the back of the screen that can, among other things, store bitmap images for the screen to display.

The screen"s headers are designed to fit into the socket on the front of the Arduino Esplora, but it is compatible with any AVR-based Arduino (Uno, Leonardo, etc. Datasheet You can use this module with Arduino Esplora.

In this Arduino Tutorial we will learn how to use an SD Card module with the Arduino Board. Also in combination with the DS3231 Real Time Clock module we will make a data logging example where we will store the data of a temperature sensor to the SD Card and import it into Excel to make a chart out of it. You can watch the following video or read the written tutorial below.

First let’s take a look at the SD Card Module. It works with standard MicroSD Cards which operating voltage is 3.3 V. Therefore, the module has a voltage regulator and a level shifter so that we can use it with the 5 V pins of the Arduino Board.

The SD Card Module have six pins, two for powering the module, the VCC and the GND pins, and four more pins for the SPI communication. Here’s how we need to connect it to the Arduino Board.

Code description:So first we need to include the standard SD and SPI libraries, create a “File” object and define the ChipSelect pin of the SPI bus, the pin 53 in my case for the Arduino Mega Board. For this example we want our code to be executed only once, so all the code will be placed in the “setup” section, while the “loop” section will remain empty.

So first we need to start the serial communication and define the ChipSelect pin as output. We have to do this because the ChipSelect pin needs to be “Low” so that the SPI communication between the module and the Arduino works.

Next, using the SD.begin() function we will initialize the SD card and if initialization is successful the “if” statement will become true and the String “SD card is ready to use.” will be printed on the serial monitor, else the string “SD card initialization failed” will be printed and also the program will be terminated.

Next, using the SD.open() function we will create a new file named “test.txt”, including the FILE_WRITE argument meaning that we can both read and write to the file. If the file already exist the SD.open() function will just open it.

So if the file has been successfully created first we will print the string “Writing to file” on the serial monitor and then using the myFile.println() function we will print the text “Testing text 1, 2 ,3…” into the file. After that we need to use close() function to ensure that the previous data written to the file is physically saved to the SD Card.

Next, we will see how we can read from the file. So again we will the same function, SD.open(), but this time as the file “test.txt” has already been created, the function will just open the file. Then using the myFile.read() function we will read from the file and print it on the serial monitor. The read() function actually reads just one character at a time, so therefore we need to use the “while” loop and the function myFile.available() to read all characters or the whole previously written data. At the end we need to close the file.

As we can see, the SD card has been successfully initialized, the writing to it has been successful as well, and also reading the written data or the string “Testing text 1, 2 ,3…” has been successful read. If we open the SD card on our computer we can see the created “test.txt” file and the written text in it.

Now let’s make another more interesting example of data logging a temperature sensor. For that purpose we will use the DS3231 Real Time Clock module which has a built-in temperature sensor as well. You can find more details about how to connect and use this module in my previous tutorial.

Code Description:First we need to include the libraries needed for both modules, then create the two objects and in the setup section initialize them.

After uploading the code the Arduino will start storing the temperature values each 3 seconds.After a while we can open the SD card on our computer to see the results.

Key Features: Use this small LCD screen with Arduino Robot, Esplora, or on breadboard. The screen is 1.77" diagonal, with 160 x 128 pixel resolution. Includes micro-sD socket The LED backlight is dimmable by PWM. The screen" s headers are laid out so it easily sockets into the Arduino Esplora and Arduino Robot. The Arduino TFT screen is a backlit LCD screen with headers. You can draw text, images, and shapes to the screen with the TFT library. There is an onboard micro-SD card slot on the back of the screen that can, among other things, store bitmap images for the screen to display. The screen" s headers are designed to fit into the socket on the front of the Arduino Esplora, but it is compatible with any AVR-based Arduino (Uno, Leonardo, etc) or with the Arduino Due. The TFT library interfaces with the screen" s controller through SPI when using the TFT library. Item Specifics The screen runs on +5 VDC

SD card is a very helpful in projects where you store a lot images or data for display. the built tin flash memory of MCUs run out easily and not suitable to store anything bigger or useful for your applications where it involved multiple graphical images.

Youcan use Wokwi Arduino Simulator to learn Arduino programming You can use several peripherals such as sensors (temperature, pressure, accelerometer, gyro. etc), displays (LEDs, OLEDs, TFT, Character LCD, FastLED matrix and more). In this article you will learn how an SD card be used to store images or even executable code.. or to store MP3 and video files to play on a TFT display.

SDcard simulation has just been enabled on theWokwi Arduino Simulator. It means, it has a lot of scope to become more resourceful. Presently there is aGitHub ticketwhere you can track all the details. We will be glad to hear from you any suggestions, which you would like to share. Together, we can make the future SD card projects.

here is the code. I would rather suggest you to visit the Arduino simulation page given above for the complete working as well as latest code.#include

Often times, we have the need for a way to store data in our projects, and most of the time, the EEPROM which comes readily to mind has a limited storage capacity, and issues with the format and nature of data it can hold. All this and more makes it probably not the best for storing data like text, CSV, audio, video or image files. To get around this we could use an SD card to store the data, and remove the card when we need to view on some other platform etc. That is why today’s project is focusing on how to interface an SD card module with an Arduino.

The Arduino Micro SD card Module is an SPI Communication based device. It is compatible with the TF SD cards used in mobile phones and can be used to provide some sort of external storage for micro controller and microprocessor based projects, to store different kind of data types from images to videos. SD cards generally are 3.3v logic level based devices, but with the aid of the Micro SD card module, the signals are converted to 5v via a logic level converter implemented on the SD card Module.

The SD card module as earlier stated, communicates with the arduino over the SPI (serial Peripheral interface) communication protocol and it is connected to the arduino hardware SPI pins. The SPI pins on an Arduino differs from one arduino to the other, but on the UNO which was used for this project, it is found between pin 10 to 12. To further highlight the connection made in the fritzing schematics above, below is a pin map of the connection between the SD card and the Arduino Uno;

The code for this tutorial will be based on the standard SD.h arduino library. It is one of the libraries that comes with the the installation of the IDE. The aim of this code is to basically show us the functions that can be performed with the SD card module, including read, write, etc.

So to jump right in, the first thing we do in the code is include the libraries that we will be using as shown below. We will basically be using the Arduino SD library and the SPI.h library which allows us to easily use the Arduino hardware SPI.

After the libraries have been declared, the next thing we do is declare the pin to which the CS pin of the SD card module is connected to the arduino. The CS pin is the only one that is not really fixed as any of the Arduino digital pin. We didn’t need to declare the other SPI pins since we are connected to the generic SPI pins and we have the SPI library included. After declaring the pin, we then create an object file, which will be used later on to store data on the SD card.

Next we move to the setup() function of the arduino code. The first thing we do is start the serial communication at 9600 baud rate. We then initialize the SD card with the next line of code, after which we create a file named test.txt and then write to it using the writeToFile() function. After writing to the file, it is closed. This section of the void setup() function was just used to demonstrate how easy it is to write  text/data to a file.

Since this was just a demo sketch to show how to read and write files, there was no point to run the code multiple times so they were all placed in the void setup() function which runs just once, instead of putting it in a void loop which runs for as long as you have power. Thus the void loop was included but with nothing inside, as you may have noticed, your arduino code will not compile without the void loop() function included. After the loop() function,are the code for the functions that were used under the void setup(), to read or write to the SD card.

Copy the code above and paste it into the Arduino IDE, Upload it to your board and you should see something like what is displayed below on your serial monitor.

I"ve frequently had a project where I wanted to write data to an SD card, or read from an SD card, but didn"t have enough I/O lines available to wire up the SPI SD card interface, or else the SPI lines were already in use, or else the processor I was using didn"t have enough RAM to run the SD library.

The ideal solution seemed to be an SD module with an I2C interface, but despite much searching on the web I couldn"t find one, so I decided to build one myself.

I initially thought of basing the circuit on the ATtiny841, like my earlier I2C GPS Module, but I underestimated the amount of RAM needed by the SD library, and the ATtiny814 only provides 512 bytes. I therefore switched to the 1‑series ATtiny1614 which provides 2 Kbytes.

For the controller I used an ATtiny1614. The SD library uses a lot of RAM so you need about 830 bytes, and the ATtiny804 or ATtiny814 aren"t suitable as they only have 512 bytes. I also tried an ATtiny1604, but that didn"t work, presumably because the 1 Kbytes of RAM doesn"t leave enough room for the stack. I"m pretty sure an ATtiny1624 should work, but I haven"t tried it.

The SD card module includes a CD pin which is connected to GND when a card is not inserted. You could connect this to a spare I/O line defined with INPUT_PULLUP to allow you to detect when a card is present.

You can use the I2C SD-Card Module with the Arduino Wire library, but it works best with my TinyI2C library; see Tiny I2C Routines for all AVR Microcontrollers. I give some examples in the following sections. Using TinyI2C it took 15 seconds to save the raw image from a 240x240 TFT display, consisting of 115200 bytes, to an SD Card. Reading it back to the display took 10 seconds.

The following example writes the bytes 48 to 90 (ASCII characters "0" to "Z") to the file "A1". Arduino Wire uses a 32-byte buffer, so you have to divide up what you"re writing into sections of not more than 32 bytes:

The following example reads the 43 characters we wrote to the file in the previous example, and prints them out using Serial.print(). Again, Arduino Wire uses a 32-byte buffer so we have to divide up what we are reading into 32-byte sections:

In this project I"ve implemented the essential functionality to read and write files to an SD card, but you could extend it to support the other features of the Arduino SD library

This is SainSmart 5 inch TFT LCD module with the TFT LCD shield kit for Arduino enthusiasts.It includes one piece of 5 inch TFT LCD display and a TFT LCD shield for Arduino MEGA2560. We will provided you the whole document including the example project of  Arduino MEGA2560 with the kit. We will supply you the technical support after your purchase.

This is the new MEGA2560 R3. In addition to all the features of the previous board, the MEGA now uses an ATMega16U2 instead of the ATMega8U2 chip. This allows for faster transfer rates and more memory. No drivers needed for Linux or Mac (inf file for Windows is needed and included in the Arduino IDE), and the ability to have the Uno show up as a keyboard, mouse, joystick, etc.

The MEGA2560 R3 also adds SDA and SCL pins next to the AREF. In addition, there are two new pins placed near the RESET pin. One is the IOREF that allow the shields to adapt to the voltage provided from the board. The other is a not connected and is reserved for future purposes. The MEGA2560 R3 works with all existing shields but can adapt to new shields which use these additional pins.

It is 100% compatible with the normal MCU like ARM AVR PIC and 8051,especially on Arduino family such as Arduino Due and Arduino MEGA2560(R3). The module uses the LCD controller Chip SSD1963 with 5 inch LCD including the touchscreen.

LCD-specified initialization code is provided, so that you can save time to optimize power control register and gamma curves for best display performance. We have test the provided code, it gives the best display performanace

It is 100% compatible with the normal MCU like ARM AVR PIC and 8051,especially on arduino family such as arduino due and arduino mega2560(R3).The module uses the LCD controller Chip SSD1963 with 5 inch LCD including the touchscreen.

The shield defines that all the the data transmit ports are PC1-PC8 and PC12-PC19,the controll pins are PD0-PD3.The perfect design could realize that the data transmits in high speed.The SPI interface is designed in the ISP header of arduino due so that the SPI transfer with DMA could be achieved in high speed with no drag.

This Arduino album project is simple as it uses mainly an Arduino Uno board and an Arduino touch LCD shield only. The photographs to be displayed are converted to 240×320-pixel size with 24-bit colour format in BMP (bitmap) files using Microsoft Paint (or similar) software and stored on a micro SD card that is normally used for cell phones.

The Arduino Uno is a widely used microcontroller board based on Atmega328P microprocessor that is used in Arduino family boards. It has 14 digital input/output pins of which six can be used as PWM outputs and six as analogue inputs, and a USB port with 16MHz quartz crystal.

The Arduino touch LCD shield works on ILI9341 chip and has a built-in microSD card. The shield’s LCD display is sufficiently big (6cm, diagonally), bright (with four white-LED backlight), and colourful (18-bit having 262144 different shades). It has good resolution of 240×320 pixels with individual pixel control, 8-bit digital interface, plus four control lines with reset pin. The SD card has four more control pins. All the pin connections are directly compatible with Arduino Uno board, which eliminates wiring and new PCB requirement. It uses 3.3V power supply and supports both 3.3V or 5V logic levels.

Here MAX_FILES is the maximum number of files to be stored in the SD card and to be displayed sequentially, and DISP_DELAY is the delay (or time gap) in milliseconds for displaying each photograph.

Now disconnect the SD card reader from the computer and take out the microSD from card reader. Insert the microSD into the microSD card slot in Arduino LCD shield, as shown in Fig. 2.

Properly position the Arduino LCD shield on the Arduino Uno board, matching the 5V, 3.3V, and GND pins. Connect a 9V DC power supply to the Arduino Uno board.

Once the root folder is read from the SD card, the list of files stored in the SD card will be displayed on the LCD screen. Thereafter the photographs will be displayed sequentially.

(Note. The original BMP file supports colours up to 24-bit resolution, whereas LCD shield supports colours up to 18-bit resolution. So, display output may have slight mismatch with colours of original BMP file.)

In this project, I will show you what is an SD Card Module, how to interface a MicroSD Card Adapter with Arduino and how the Arduino SD Card Module Interface can be used for Data Logging of sensor data.

We have interfaced several sensors like Humidity, Temperature, RTC Clock, etc. with Arduino in several earlier projects. All we did in those projects is hook-up a sensor with Arduino and view the sensor’s data on either an LCD or the Arduino IDE’s Serial Monitor.

In our case, if we want to record the data from a sensor using Arduino, we have to interface an SD Card with Arduino. In order to do that, you have to use a MicroSD Card Adapter or an SD Card Module and understand about the Arduino SD Card Module Interface.

A Micro SD Card is a flash based, removable memory device. It is non-volatile memory and is often used in mobile phones and other consumer electronic devices.

First thing is the operating voltage. Almost all Micro SD Cards work in a voltage range of 2.7V to 3.6V (typically, 3.3V). Second, is the communication interface. A Micro SD card supports SPI Communication.

An SD Card Module or a Micro SD Card Adapter is a simple board which facilitates connection between a Micro SD card and a Microcontroller like Arduino. The following is the image of a typical SD Card Module.

Since Arduino operates at 5V and the Micro SD Card operates at 3.3V, a typical Micro SD Card Adapter or an SD Card Module basically consists of two important components. They are the 3.3V Voltage Regulator IC and a 5V to 3.3V Level Converter IC for the communication pins.

Talking about pins, as I have mentioned that a Micro SD Card supports only SPI Communication, the SD Card Module has pins for SPI Communication. So, the pins on an SD Card Module are as follows.

Now that we have seen a little bit about the SD Card Module, let us proceed with interfacing one with Arduino. First thing to remember is that the communication between Arduino and the SD Card Module is through SPI Interface.

Coming to the Arduino SD Card Module Interface, I have designed two circuits for this project. In the first circuit, I have simply made the connection between the Arduino and the SD Card Module and extract the information of the card. This circuit can be considered as an Arduino SD Card Module Hook-up Guide.

In the second circuit, the magic of actual data logging happens. It is an extension to the first circuit with sensors connected to the Analog Pins of Arduino and the data from these sensors is captured on an event.

Connect the MOSI, MISO, SCK and CS (SS) pins of the SD Card Module to Digital I/O Pins 11, 12, 13 and 10 of Arduino. Connect the VCC and GND pins of the SD Card Module to +5V and GND of Arduino.

Insert a Micro SD Card in the slot provided on the SD Card Module and make the necessary connections. Upload the code to Arduino and open the Serial Monitor. If everything goes well, you can see the information about your Micro SD Card on the serial monitor.

The next circuit is about data logging on to a Micro SD Card using the Arduino and SD Card Module. The following image shows three Potentiometers connected to three Analog pins of Arduino.

The Interface of Arduino and Micro SD Card Adapter is same as the earlier circuit. Additionally, three potentiometers are used as analog sensors and are connected to A0, A1 and A2 of Arduino UNO.

As I have mentioned earlier, data logging happens either at a predefined interval of time or in case an event is triggered. For the first case i.e., to log the data based on time, you have to interface an RTC Module to Arduino and the data from the sensor can be updated to the log at a certain time interval.

Every now and then, you get an idea for an Arduino project that needs a way to store a lot of log data and other information, like a GPS logger or a temperature logger.

The solution is to use something that can be found in any digital camera or MP3 player: Flash Cards! They are often called SD cards or microSD cards. Their ability to fit Gigabytes of data into a space smaller than a coin makes them an essential part of our lives.

A standard microSD card has an operating voltage of 3.3 V. As a result, we cannot connect it directly to circuits that use 5V logic; in fact, any voltages above 3.6V may permanently damage the microSD card. That is why the module includes an onboard ultra-low dropout voltage regulator capable of regulating voltage to 3.3V.

The module also includes a 74LVC125A logic level shifter chip, allowing for safe and easy communication with your favorite 3.3V or 5V microcontroller without damaging the SD card.

There’s a microSD card socket on the front! Any microSD memory card will work perfectly. The proper direction to insert a microSD card is usually printed on the module.

SDIO mode is much faster and is used in mobile phones, digital cameras, and other devices. However, it is more complicated and requires the signing of non-disclosure agreements. Because of this, hobbyists like us are unlikely to come across SDIO mode interface code.

If you have a new SD card, chances are it’s already pre-formatted with a FAT file system; however, you may encounter issues with how the factory formats the card. Or, if you have an old card, it needs to be formatted. In any case, it’s a good idea to format the card before using it.

It is recommended that you use the official SD card formatter utility developed by the SD association. It can solve a lot of problems caused by bad formatting! Download and run the formatter on your computer; simply select the appropriate drive and click Format.

Now we are left with the pins that are used for SPI communication. Because microSD cards require a lot of data transfer, they perform best when connected to the microcontroller’s hardware SPI pins.

Communicating with an SD card is a lot of work, but luckily for us, the Arduino IDE already includes a very useful library called SD that makes reading and writing SD cards easier.

Let’s start with a simple CardInfo example sketch. This sketch doesn’t write any data to the card. Instead, it tells you if the card is recognized and shows you some information about it. This can be very useful when determining whether or not an SD card is supported. It is therefore recommended that you run this sketch once before trying out a new card.

Now, insert the SD card into the module and upload the sketch. When you open the Serial Monitor, you may see different results depending on the scenario.

If everything is fine, you should see some useful information. For example, in our case, the card type is SDHC (SD High Capacity), the volume type is FAT32, and the size of the card is 4 GB.

Although the card responded, all the data is inaccurate. As you can see, there is no Manufacturer ID or OEM ID, and the Product ID is ‘N/A.’ It appears the card returned SD errors.

If there is a wiring error or the card is permanently damaged, you will see something similar to this. You can see that it couldn’t even initialize the SD card.

Next, we declare the Arduino pin to which the SD card module’s CS (Chip Select) pin is connected. Except for the CS pin, we do not need to declare any other SPI pins because we are using a hardware SPI interface and these pins are already declared in the SPI library.

In the setup() section, we initialize the serial communication and call the SD.begin() function. If it manages to recognize the card, it prints “initialization done.” on the serial monitor. If it doesn’t, it prints “initialization failed!” and the program terminates.

We then close the file by using the close() function. This function closes the file and makes sure that any data written to it is saved to the SD card.

You can open files in a directory. To open a file in the directory, for example, use SD.open("/myfiles/example.txt"). Remember that the path to the file is relative.

The SD card library does not support long filenames because it uses the 8.3 filename format. So keep file names short. For instance, “datalog.txt” is fine, but “My Sensor log file.text” is not!