SD card example fail

[agdl]

From @maxcpr on August 18, 2015 18:2

a little bit changed example from IDE (SD listfiles), file listing moved to "loop".
Code stops listing microSD card after 17-20 loops (arduino nano).
(there is similar code, also listing files on microsd, that works fine on the same hardware)

/*
  Listfiles

 This example shows how print out the files in a 
 directory on a SD card 

 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
 modified 9 Apr 2012
 by Tom Igoe
 modified 2 Feb 2014
 by Scott Fitzgerald

 This example code is in the public domain.

 */
#include <SPI.h>
#include <SD.h>

File root;

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...");
  digitalWrite(10, 1);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(4, 0);   // turn the LED on (HIGH is the voltage level)
  delay(2000); 
  while (!SD.begin(4)) {
    Serial.println("initialization failed!");
    delay(2000); 
//    return;
  }
  Serial.println("initialization done.");
}

void loop(){
  Serial.println("starting!");
  root = SD.open("/");
  printDirectory(root, 0);
  Serial.println("done!");
  delay(2000);
  pinMode(10, OUTPUT);
  pinMode(4, OUTPUT);
  digitalWrite(10, 1);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(4, 0);   // turn the LED on (HIGH is the voltage level)


}

void printDirectory(File dir, int numTabs) {
   while(true) {

     File entry =  dir.openNextFile();
     if (! entry) {
       // no more files
       break;
     }
     for (uint8_t i=0; i<numTabs; i++) {
       Serial.print('\t');
     }
     Serial.print(entry.name());
     if (entry.isDirectory()) {
       Serial.println("/");
       printDirectory(entry, numTabs+1);
     } else {
       // files have sizes, directories do not
       Serial.print("\t\t");
       Serial.println(entry.size(), DEC);
     }
     entry.close();
   }
}

Copied from original issue: arduino/Arduino#3696

[agdl]

From @shiftleftplusone on September 12, 2015 15:34

I made it similar, providing a dedicated SDinit() function and aborting after 20 sec timeout:

#define fileIO_OK            +1
#define fileIO_NO_ERR         0
#define fileIO_ERR_CREATE    -1
#define fileIO_ERR_OPEN      -2
#define fileIO_ERR_REMOVE    -3
#define fileIO_ERR_WRITE     -4
#define fileIO_ERR_READ      -5
#define fileIO_ERR_IMPLAUS   -6
#define fileIO_ERR_NAME      -8
#define fileIO_ERR_SDCARD   -16

#define sd_cs    4


//=====================================================================================
// SD init
//=====================================================================================

int16_t SDinit() {
   char sbuf[50];
   uint32_t  tstamp;
   int16_t   ior=0;

   pinMode(13, OUTPUT);
   digitalWrite(13, LOW);
   tstamp = millis();
   ior=SD.begin(sd_cs);  // true on sucess; else false
   while( !ior) {      
      sprintf(sbuf, "#: ...SD not found... ");  Serial.println(sbuf);
      delay(1000);   
      ior=SD.begin(sd_cs);
      if (millis()-tstamp>20000) {Serial.println("#: ...break!"); break; }
   } 
  if(!ior) return fileIO_ERR_SDCARD;     // SD ioresult == 0
  digitalWrite(13, HIGH);
  return fileIO_OK ;            // SD init OK  == 1
}