This example shows how use the utility libraries on which the' SD library is based in order to get info about your SD card. Very useful for testing a card when you're not sure whether its working or not.
The circuit: SD card attached to SPI bus as follows: \*\* MOSI - pin 11 on Arduino Uno/Duemilanove/Diecimila \*\* MISO - pin 12 on Arduino Uno/Duemilanove/Diecimila \*\* CLK - pin 13 on Arduino Uno/Duemilanove/Diecimila \*\* CS - depends on your SD card shield or module. Pin 4 used here for consistency with other Arduino examples
created 28 Mar 2011 by Limor Fried modified 9 Apr 2012 by Tom Igoe \*/ // include the SD library: #include <SPI.h> #include <SD.h>
// set up variables using the SD utility library functions: Sd2Card card; SdVolume volume; SdFile root;
// change this to match your SD shield or module; // Arduino Ethernet shield: pin 4 // Adafruit SD shields and modules: pin 10 // Sparkfun SD shield: pin 8 // MKRZero SD: SDCARD\_SS\_PIN const int chipSelect = SS;
void setup() { // Open serial communications and wait for port to open: Serial.begin(9600); while (!Serial) { ; // wait for serial port to connect. Needed for native USB port only }
Serial.println("Initializing SD card...");
// we'll use the initialization code from the utility libraries // since we're just testing if the card is working! if (!card.init(SPI_HALF_SPEED, chipSelect)) { Serial.println("initialization failed. Things to check:"); Serial.println("\* is a card inserted?"); Serial.println("\* is your wiring correct?"); Serial.println("\* did you change the chipSelect pin to match your shield or module?"); while (1); } else { Serial.println("Wiring is correct and a card is present."); }
// print the type of card Serial.println(); Serial.print("Card type: "); switch (card.type()) { case SD_CARD_TYPE_SD1: Serial.println("SD1"); break; case SD_CARD_TYPE_SD2: Serial.println("SD2"); break; case SD_CARD_TYPE_SDHC: Serial.println("SDHC"); break; default: Serial.println("Unknown"); }
// Now we will try to open the 'volume'/'partition' - it should be FAT16 or FAT32 if (!volume.init(card)) { Serial.println("Could not find FAT16/FAT32 partition.\r\nMake sure you've formatted the card"); while (1); }
Serial.print("Clusters: "); Serial.println(volume.clusterCount()); Serial.print("Blocks x Cluster: "); Serial.println(volume.blocksPerCluster());
// print the type and size of the first FAT-type volume uint32\_t volumesize; Serial.print("Volume type is: FAT"); Serial.println(volume.fatType(), DEC);
volumesize = volume.blocksPerCluster(); // clusters are collections of blocks volumesize \*= volume.clusterCount(); // we'll have a lot of clusters volumesize /= 2; // SD card blocks are always 512 bytes (2 blocks are 1KB) Serial.print("Volume size (Kb): "); Serial.println(volumesize); Serial.print("Volume size (Mb): "); volumesize /= 1024; Serial.println(volumesize); Serial.print("Volume size (Gb): "); Serial.println((float)volumesize / 1024.0);
Serial.println("\nFiles found on the card (name, date and size in bytes): "); root.openRoot(volume);
// list all files in the card with date and size root.ls(LS_R | LS_DATE | LS_SIZE); }
This example shows how to read and write data to and from an SD card file The circuit: SD card attached to SPI bus as follows: \*\* MOSI - pin 11 \*\* MISO - pin 12 \*\* CLK - pin 13 \*\* CS - pin 4 (for MKRZero SD: SDCARD\_SS\_PIN)
created Nov 2010 by David A. Mellis modified 9 Apr 2012 by Tom Igoe
This example code is in the public domain.
\*/
#include <SPI.h> #include <SD.h>
File myFile; int readPin = 2; int writePin = 3; int counts = 1; byte readState; byte writeState; void read\_interrupt(){ readState = 1; }
void write\_interrupt(){ writeState = 1; }
void setup(){ pinMode(readPin,INPUT); pinMode(writePin,INPUT); attachInterrupt(digitalPinToInterrupt(readPin),read_interrupt,RISING); attachInterrupt(digitalPinToInterrupt(writePin),write_interrupt,RISING); // Open serial communications and wait for port to open: Serial.begin(9600); while (!Serial) { ; // wait for serial port to connect. Needed for native USB port only }
Serial.println("Initializing SD card...");
if (!SD.begin(SS)) { Serial.println("initialization failed!"); while (1); } Serial.println("initialization done."); }
void loop() { if(writeState){ writeState = 0; Serial.println("write file:"); // open the file. note that only one file can be open at a time, // so you have to close this one before opening another. myFile = SD.open("test.txt", FILE_WRITE); // if the file opened okay, write to it: if (myFile) { Serial.print("Writing to test.txt..."); myFile.println(counts); Serial.print(counts); counts++; // close the file: myFile.close(); Serial.println("done."); } else { // if the file didn't open, print an error: Serial.println("write:error opening test.txt"); } }
if(readState){ readState = 0; Serial.println("read file:"); // re-open the file for reading: myFile = SD.open("test.txt"); if (myFile) { Serial.println("test.txt:"); // read from the file until there's nothing else in it: while (myFile.available()) { Serial.write(myFile.read()); } // close the file: myFile.close(); } else { // if the file didn't open, print an error: Serial.println("read:error opening test.txt"); } } }
