Storing calibration tables on an SD card

Using Arduino Storage
21

Progress!!!

Thank you everyone for your help so far. I am very close.

I have my code successfully reading the CSV-formatted text file from the SD card, parsing that data, and inserting the floats into my array. Yeah.

Now, I have two strange things happening:

  1. My code seems to be inserting the values correctly, but when I read them from the array a second time, the first 3 or so are off. Initially, the values go in as 00.00, 00.08, -0.10, 00.56 correctly. But, when I run some Serial.println()s to check what is in the array, the first 3 or so come out as 0.00. Any idea why that is happening?

  2. My function to calculate the length of the responseArray[] seems to have stopped working as well. It returns a length of 0 now. Not sure why that is happening either. This code used to work.

Current code:

#include <SdFat.h>
#include <SdFatUtil.h>

Sd2Card card;
SdVolume volume;
SdFile root;
SdFile file;

float responseArray[] = {};
char CSV_SEPARATOR = ',';
int elementIdx = 0;
char code[] = "0000000000";
int csvSeparatorCount;

// store error strings in flash to save RAM
#define error(s) error_P(PSTR(s))

void error_P(const char* str) {
  PgmPrint("error: ");
  SerialPrintln_P(str);
  if (card.errorCode()) {
    PgmPrint("SD error: ");
    Serial.print(card.errorCode(), HEX);
    Serial.print(',');
    Serial.println(card.errorData(), HEX);
  }
  while(1);
}

void setup(void) 
{
    Serial.begin(9600);
    Serial.println("\nType any character to start");
    while (!Serial.available());
    Serial.println();
    String tmpString = "";
    boolean equalsReadToken = false;
    
    
    // initialize the SD card at SPI_HALF_SPEED to avoid bus errors with
    // breadboards.  use SPI_FULL_SPEED for better performance.
    if (!card.init(SPI_HALF_SPEED)) error("card.init failed");
    
    // initialize a FAT volume
    if (!volume.init(&card)) error("volume.init failed");
    
    // open the root directory
    if (!root.openRoot(&volume)) error("openRoot failed");
    
    // open a file
    if (file.open(&root, "CSV.TXT", O_READ)) {
      Serial.println("Opened CSV.TXT");
    }
    
    else
    {
      error("file.open failed");
    }
    
    int16_t c;

    while ((c = file.read()) > 0)
    {

      if ((char)c == CSV_SEPARATOR) 
      {
        char carray[tmpString.length() + 1]; //determine size of the array
        tmpString.toCharArray(carray, sizeof(carray)); //put readStringinto an array
        float n = atof(carray); //convert the array into an Integer
        
        responseArray[elementIdx] = n;
        
        Serial.print("Retrieved element ");
        Serial.print(elementIdx);
        Serial.print(" with a value of ");
        Serial.println(responseArray[elementIdx]);

        tmpString = "";
        csvSeparatorCount++;
        if (csvSeparatorCount == 2) {
          csvSeparatorCount = 0;
          elementIdx = 0;
        } else {
          elementIdx++;
        }
      } else {
        csvSeparatorCount = 0;
        if (((char)c != '\n')&&((char)c !='\r')) {  //prevent newline chars to end up in tmpString
          tmpString += (char)c;                    //accumulate the chars to eventually hold the contents of one element
        }
      }
    }
    file.close();
    
    int responseArrayLength = ((sizeof(responseArray)/sizeof(char *))/2);
    
    responseArrayLength = 30; //Why isn't the dynamic version working?
    
    Serial.print("\nSuccessfully loaded a reponse array from the SD card that is ");
    Serial.print(responseArrayLength);
    Serial.println(" elements long.\n");
    
    for (int loopIteration = 0; loopIteration < responseArrayLength; loopIteration++)
    {
      Serial.print("responseArray[");
      Serial.print(loopIteration);
      Serial.print("] = ");
      Serial.println(responseArray[loopIteration]);
    }
    
  Serial.println("\nDone.\n");
}

void loop(void) {}