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Diffstat (limited to 'libraries/SD/examples/ReadWrite')
| -rw-r--r-- | libraries/SD/examples/ReadWrite/ReadWrite.pde | 79 | 
1 files changed, 79 insertions, 0 deletions
diff --git a/libraries/SD/examples/ReadWrite/ReadWrite.pde b/libraries/SD/examples/ReadWrite/ReadWrite.pde new file mode 100644 index 0000000..9957218 --- /dev/null +++ b/libraries/SD/examples/ReadWrite/ReadWrite.pde @@ -0,0 +1,79 @@ +/* +  SD card read/write +  + 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 +  + created   Nov 2010 + by David A. Mellis + updated 2 Dec 2010 + by Tom Igoe +  + This example code is in the public domain. + 	  + */ +  +#include <SD.h> + +File myFile; + +void setup() +{ +  Serial.begin(9600); +  Serial.print("Initializing SD card..."); +  // On the Ethernet Shield, CS is pin 4. It's set as an output by default. +  // Note that even if it's not used as the CS pin, the hardware SS pin  +  // (10 on most Arduino boards, 53 on the Mega) must be left as an output  +  // or the SD library functions will not work.  +   pinMode(10, OUTPUT); +    +  if (!SD.begin(4)) { +    Serial.println("initialization failed!"); +    return; +  } +  Serial.println("initialization done."); +   +  // 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("testing 1, 2, 3."); +	// close the file: +    myFile.close(); +    Serial.println("done."); +  } else { +    // if the file didn't open, print an error: +    Serial.println("error opening test.txt"); +  } +   +  // 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("error opening test.txt"); +  } +} + +void loop() +{ +	// nothing happens after setup +} + +  | 
