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Topic: Hello and Help! SD card initialised indication... (Read 831 times) previous topic - next topic

Firstly hello to all, my first post on the forum and already looking forward to many more. Been playing with the UNO board and Ethernet shield for a couple of weeks now for a college project which reads 3 analogue sensors and data logs them using a micro sd embedded in the Ethernet shield. All going well apart from.....

It seems the SD card (and others I've formatted and used) intermittently fails to initialise. It wasn't too much of a problem when I had it connected to my PC as I could use the serial monitor to check but I've now prototyped the circuit in a project box....so  I cant connect my laptop to it to check if initialisation has been successful (no room for the USB lead). I've tested the circuit works in the current configuration (ie, in its project box) however, when I turned it on for a 12hr recording period yesterday.....there was no file on the card.

Question is, i'm hoping to insert a little code into the sketch which drives a digital I/O low when initialisation is complete and the logging commences (thus turning off an LED).....sounds simple....?

I'm basically using a slightly modified version of the standard SD Card data logging example within the IDE.....as seen below:

Any suggestions welcome


/*
 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 4

created  24 Nov 2010
modified 9 Apr 2012
by Tom Igoe
Edited for my application, 1/05/2013...Adrian Wilkes

This example code is in the public domain.
   
*/

#include <SD.h>

// On the Ethernet Shield, CS is pin 4. Note that even if it's not
// used as the CS pin, the hardware CS pin (10 on most Arduino boards,
// 53 on the Mega) must be left as an output or the SD library
// functions will not work.
const int chipSelect = 4;

void setup()
{
// Open serial communications and wait for port to open:
 Serial.begin(9600);
  while (!Serial) {
   ; // wait for serial port to connect. Needed for Leonardo only
 }


 Serial.print("Initializing SD card...");
 // make sure that the default chip select pin is set to
 // output, even if you don't use it:
 pinMode(10, OUTPUT);
   
 // 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:
   return;
 }
 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 the <4 indicates we want to read pins up to but not including 4,
 //the <3 seems to place 3 comma's:
 for (int analogPin = 0; analogPin < 4; analogPin++) {
   int sensor = analogRead(analogPin);
   dataString += String(sensor);
   if (analogPin < 3) {
     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("Test1May.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);
   delay (2000);
 }  
 // if the file isn't open, pop up an error:
 else {
   Serial.println("error opening datalog.txt");
 }
}

SurferTim

Intermittently the w5100 SPI is trashing up the SPI bus unless you disable it during your SD tests. Add the line below to your setup function.
Code: [Select]
Serial.print("Initializing SD card...");
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(10, OUTPUT);
  // Add this line. It disables the w5100 SPI
  digitalWrite(10, HIGH);

  // now SD.begin()

How does that do?

fat16lib

Quote

Intermittently the w5100 SPI is trashing up the SPI bus unless you disable it during your SD tests. Add the line below to your setup function.


This is not likely the problem since the SD library makes SS an output and sets it high.  SS is pin 10 on an Uno.

SurferTim

This is not needed either, but if I do one, I do both. Just a habit.
Code: [Select]
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(10, OUTPUT);

If it makes no difference, then the rest is up to you.  ;)

fat16lib

I agree.  You should make chip select an output and set chip select high for other SPI devices before intializing any SPI device.

After all that, I managed to sort it. It was simply a case of adding an integer and adding the state control in the if function related to the 'error opening data file'...

Tested and works well, an LED, connected to digital pin 2 now illuminates if there is an error opening the datalog.text.....a quick press of the reset button sorts it.

Code: [Select]
/*
  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 4

created  24 Nov 2010
modified 9 Apr 2012
by Tom Igoe
Editited for my application, 1/05/2013...Adrian Wilkes

This example code is in the public domain.

*/

#include <SD.h>

// On the Ethernet Shield, CS is pin 4. Note that even if it's not
// used as the CS pin, the hardware CS pin (10 on most Arduino boards,
// 53 on the Mega) must be left as an output or the SD library
// functions will not work.
const int chipSelect = 4;
int fail_led = 2;

void setup()
{
// Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }


  Serial.print("Initializing SD card...");
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(10, OUTPUT);
  pinMode(fail_led, OUTPUT);
   
   
  // 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:
    return;
  }
  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 the <4 indicates we want to read pins up to but not including 4,
  //the <3 seems to place 3 comma's:
  for (int analogPin = 0; analogPin < 4; analogPin++) {
    int sensor = analogRead(analogPin);
    dataString += String(sensor);
    if (analogPin < 3) {
      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("Test1May.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);
    digitalWrite(fail_led, LOW);
    delay (2000);
  } 
  // if the file isn't open, pop up an error:
  else {
    digitalWrite(fail_led, HIGH);
    Serial.println("error opening datalog.txt");
   
  }
}

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