reading text from an sd card

Using Arduino Programming Questions
16

Where do you think the bottleneck is?

Is this a trick question ? :wink:

SD card speed depends. I read that it gets slower when you delete / create many files often on a card, without re-formatting the card.

What's your result ?

BTW, I would not use String for the filenames, but

 static char filename[] = "fr0#.txt";
 
 for (int tens = '0'; tens< '3'; tens++) {
   for (int ones = '0'; ones <='9'; ones++) {
      filename[3] = ones;
      // open the file for reading:
      myFile = SD.open(filename);
      // etc.
   }
   filename[2]++;
 }

There might be enough space for 30 dynamic Strings besides the 512 byte data, but in a "run forever" scenario it's a bad idea...

And check that your byteCount does not exceed the limit (512) with a bad file