Reading data from SD card in Arduino - Cheat Sheet & Quick Revision

Recall & Review

beginner

What library do you need to include to read data from an SD card in Arduino?

You need to include the SD library, which provides functions to access files on the SD card.

beginner

How do you initialize the SD card in your Arduino sketch?

Use SD.begin(chipSelectPin) where chipSelectPin is the pin connected to the SD card's chip select. It returns true if initialization succeeds.

beginner

How do you open a file for reading from the SD card?

Use File myFile = SD.open("filename.txt", FILE_READ). This opens the file named "filename.txt" for reading.

intermediate

How do you read data from an open file on the SD card?

You can use myFile.read() to read one byte at a time or myFile.readStringUntil('\n') to read a line until a newline character.

beginner

Why is it important to close a file after reading from the SD card?

Closing the file with myFile.close() frees up memory and ensures data integrity on the SD card.

Which Arduino library is used to read data from an SD card?

A SPI

B Wire

C SD

D EEPROM

The SD library is specifically designed for reading and writing files on SD cards.

What does SD.begin(chipSelectPin) do?

A Formats the SD card

B Reads data from the SD card

C Closes the SD card connection

D Initializes the SD card and SPI communication

It sets up the SD card and SPI bus so you can access files.

How do you open a file named "data.txt" for reading?

A File myFile = SD.open("data.txt", FILE_READ)

B File myFile = SD.read("data.txt")

C File myFile = SD.begin("data.txt")

D File myFile = SD.close("data.txt")

The open() function opens the file for reading or writing.

Which function reads one byte from an open file?

A myFile.open()

B myFile.read()

C myFile.close()

D myFile.write()

read() reads one byte from the file.

Why should you call myFile.close() after reading?

A To free memory and save changes

B To open the file again

C To delete the file

D To format the SD card

Closing the file frees resources and ensures data is saved properly.

Explain the steps to read a text file from an SD card using Arduino.

Think about setup, opening, reading, and closing.

Why is it important to check if SD.begin() returns true before reading files?

What happens if the SD card is missing or not working?