Hi I am intending to use a micro SD Card Module for a datalogger project. I have read a few articles on the forum where level shifters are required by the SD Card Module for better functionality. However, my SD Card is working without it and can read and write data from the Arduino just fine.
When I write data to SD Card from the Arduino, it works. After that if I tried to read the file from Arduino, that also works. However, when I connect the SD Card module to PC and try to open the file that the data was written to, the file does not open.
Post this even if I try to read the file from the Arduino after connecting to the PC, it fails. Somehow connecting the SD card to the PC corrupts the file. I do not understand why this is happening? Is there a fix for this?
SD Card Module being used
Code for writing Data
/*
SD card datalogger
This example shows how to log data from three analog sensors
to an SD card using the SD library.
The circuit:
analog sensors on analog ins 0, 1, and 2
SD card attached to SPI bus as follows:
** MOSI - pin 11
** MISO - pin 12
** CLK - pin 13
** CS - pin 10 (for MKRZero SD: SDCARD_SS_PIN)
created 24 Nov 2010
modified 9 Apr 2012
by Tom Igoe
This example code is in the public domain.
*/
#include <SPI.h>
#include <SD.h>
const int chipSelect = 10;
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.print("Initializing SD card...");
// see if the card is present and can be initialized:
if (!SD.begin(chipSelect)) {
Serial.println("Card failed, or not present");
// don't do anything more:
while (1);
}
Serial.println("card initialized.");
}
void loop() {
// make a string for assembling the data to log:
String dataString = "";
// read three sensors and append to the string:
for (int analogPin = 0; analogPin < 3; analogPin++) {
int sensor = analogRead(analogPin);
dataString += String(sensor);
if (analogPin < 2) {
dataString += ",";
}
}
// open the file. note that only one file can be open at a time,
// so you have to close this one before opening another.
File dataFile = SD.open("datalog.txt", FILE_WRITE);
// if the file is available, write to it:
if (dataFile) {
dataFile.println(dataString);
dataFile.close();
// print to the serial port too:
Serial.println(dataString);
}
// if the file isn't open, pop up an error:
else {
Serial.println("error opening datalog.txt");
}
}
Code for reading the data
/*
SD card file dump
This example shows how to read a file from the SD card using the
SD library and send it over the serial port.
The circuit:
SD card attached to SPI bus as follows:
** MOSI - pin 11
** MISO - pin 12
** CLK - pin 13
** CS - pin 10 (for MKRZero SD: SDCARD_SS_PIN)
created 22 December 2010
by Limor Fried
modified 9 Apr 2012
by Tom Igoe
This example code is in the public domain.
*/
#include <SPI.h>
#include <SD.h>
const int chipSelect = 10;
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.print("Initializing SD card for reading...");
// see if the card is present and can be initialized:
if (!SD.begin(chipSelect)) {
Serial.println("Card failed, or not present");
// don't do anything more:
while (1);
}
Serial.println("card initialized.");
// open the file. note that only one file can be open at a time,
// so you have to close this one before opening another.
File dataFile = SD.open("datalog.txt");
// if the file is available, write to it:
if (dataFile) {
while (dataFile.available()) {
Serial.write(dataFile.read());
}
dataFile.close();
}
// if the file isn't open, pop up an error:
else {
Serial.println("error opening datalog.txt");
}
}
void loop() {
}
