ESP8266 Community Forum

- Tue Sep 27, 2016 2:02 pm #55770 Hi,
I am interfacing a micro-sd card module with nodemcu.
Along with miso, mosi, and sck, I am using CS as GPIO4 (D2 on nodemcu).
I loaded the cardinfo.ino sketch and it shows the following:

Code: Select allInitializing SD card...Wiring is correct and a card is present.

Card type: SDHC

Volume type is FAT32

Volume size (bytes): 3644850176
Volume size (Kbytes): 3559424
Volume size (Mbytes): 3476

But when I try wring any file it fails:
The entire code is:

Code: Select all#include "Arduino.h"
/*
  SD card test

 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;
File myFile;


// 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
const int chipSelect = D2;

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
  }
  pinMode(chipSelect, OUTPUT);

  Serial.print("\nInitializing 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_FULL_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?");
    return;
  } else {
    Serial.println("Wiring is correct and a card is present.");
  }

  // print the type of card
  Serial.print("\nCard 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.\nMake sure you've formatted the card");
    return;
  }


  // print the type and size of the first FAT-type volume
  uint32_t volumesize;
  Serial.print("\nVolume type is FAT");
  Serial.println(volume.fatType(), DEC);
  Serial.println();

  volumesize = volume.blocksPerCluster();    // clusters are collections of blocks
  volumesize *= volume.clusterCount();       // we'll have a lot of clusters
  volumesize *= 512;                            // SD card blocks are always 512 bytes
  Serial.print("Volume size (bytes): ");
  Serial.println(volumesize);
  Serial.print("Volume size (Kbytes): ");
  volumesize /= 1024;
  Serial.println(volumesize);
  Serial.print("Volume size (Mbytes): ");
  volumesize /= 1024;
  Serial.println(volumesize);


  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);
  // 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(void) {

}


Now few words on the card module:
it has got an onboard 3.3v regulator and a logic level shifter chip. These are provided to handle with 5v inputs perhaps.
For nodemcu all lines are 3.3v, so after level shifting would it remain at 3.3v?
Another thing the card is brand new (not formatted yet) and its a 8gb card, but the log shows it to be a 4gb card.

Can anyone help please?

Thanks in advance.
Debojit

- Tue Sep 27, 2016 10:28 pm #55784 Hi,
Just an update:
I tried another 4 gb card, for this case it can enumerate all the files, but still reading/writing is failing.
Kindly suggest what to do.
I will try to connect it with an arduino and post the results.

Thanks,
Debojit

- Wed Sep 28, 2016 6:21 am #55800 Hi, when you say it fails does it return "error opening test.txt" of some other error. I've used that sketch without problems.

- Wed Sep 28, 2016 11:03 am #55818 Hi,
The problem is fixed.
dont know how, but when i put the read-write sample as it is without any modification it worked. The code I posted contains the code to retrieve volume information and then it processes file. Probably some fil system reset happened in between that caused file read/write not working.
I will see to it later.

Thanks for all your assistance.
Debojit