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[on:]

Hello,

I have a datalogging + LCD stacking shields and I am providing signals to store in a SD card (SDHC 16gb SanDisk Extreme Pro).  My code checks and returns a success when SD.begin() is sent.

But when I create an object and try to open open it.

Code:

File dataFile = SD.open("LOG.csv", FILE_WRITE);

I keep getting a 0 and I cannot open the SD card.

Any suggestions?

[Reply #1 on:]

Any suggestions?

The usual one. Post your code.

[Reply #2 on:]

PaulS, sorry about that - I have a poor tendancy leaving it out.

Code:

#include <Wire.h>
#include <I2C_Anything.h>
#include <LiquidCrystal.h>
#include <SD.h>

int CS_PIN = 10;

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

const byte MY_ADDRESS = 42;

float REFRESH_RATE = 0.0;
long ID = 1;

void setup()
{
  Serial.begin(9600);
  Wire.begin(MY_ADDRESS); 
  Wire.onReceive(receiveEvent);
 
  lcd.begin(16,2);
  pinMode(CS_PIN, OUTPUT);
 
  lcd.setCursor(0,0);
  lcd.print("ME: ");
  lcd.setCursor(8,0);
  lcd.print("SE: ");
  lcd.setCursor(0,1);
  lcd.print("Datalog: ");
 
  if (!SD.begin(CS_PIN))
  {
    Serial.println("Card Failure");
    return;
  }
  Serial.println("Card Ready");
}

volatile boolean haveData = false;
volatile int X;
volatile int Y;
int LOOP_COUNTER = 0;

void loop()
{ 
  if (haveData)
  {
    lcd.setCursor(3,0);
    lcd.print(X);
    lcd.setCursor(11,0);
    lcd.print(Y);
    haveData = false;   
  }
 
  File dataFile = SD.open("LOG.csv", FILE_WRITE);
 
  if (LOOP_COUNTER == 500)
  {
    if (dataFile)  <--- always prints 0
    {
      dataFile.print(millis());
      dataFile.print(", ");
      dataFile.print(ID);
      dataFile.print(", ");
      dataFile.print(X);
      dataFile.print(", ");
      dataFile.println(Y);
      dataFile.close();
      lcd.setCursor(9,1);
      lcd.print("Success");
      ID++;
    }
    else
    {
      lcd.setCursor(9,1);
      lcd.print("Failure");
    }
   
  LOOP_COUNTER = 0; 
 
  }   
  LOOP_COUNTER++;
}



void receiveEvent (int howMany)
{
  if (howMany >= (sizeof X) + (sizeof Y))
  {
    I2C_readAnything (X);
    I2C_readAnything (Y);
    haveData = true;
  }
}

[Reply #3 on:]

int CS_PIN = 10;

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

const byte MY_ADDRESS = 42;

float REFRESH_RATE = 0.0;

By convention, all capital letter names are reserved for constants. So, these are all good.

Code:

int LOOP_COUNTER = 0;

Now, a counter can hardly be considered constant, can it?

I'd try stripping stuff out of that program, to see whether the problem is with the card, or a library you are using, or some other issue. For instance, the LCD has nothing to do with reading from/writing to the SD card. So, out it goes.

Similarly, the I2C and Wire classes have nothing to do with reading from/writing to the SD card. So, out they go.

That leaves you with a much smaller program to test JUST the write to the card.

What SD shield are you using? Some of them do not support such large cards.

[Reply #4 on:]

PaulS,

Thank you for your help, I will do the changed and test the SD card alone - I contacted the manufacturer and the shield should be okay for the HCSD I am using.  The shield I am using is below:

http://arduino-direct.com/sunshop/index.php?l=product_detail&p=290

Sorry for such a late reply - I have been really sick with the flu.

Daniel

[Reply #5 on:]

The SD Card works just fine, but I realized that I was using the wrong library.  I need to be using SdFat, it is very robust so I hope to understand this quickly, thank you for your help.

Daniel