A library for manipulate Intel Hex data?
Why does it have to be in Intel Hex format? You could write out the EEPROM to the serial port one byte to a line, or something. Something like this:



#include &lt;EEPROM.h&gt;

void setup ()
{
  Serial.begin (115200);
  Serial.println ();

  for (int addr = 0x0000; addr &lt; 0x0010; addr++)
    {
    Serial.print ("Address = ");
    Serial.print (addr, HEX);
    Serial.print (", value = ");
    Serial.println (EEPROM.read(addr), HEX);
    }

}  // end of setup

void loop ()
{
}  // end of loop


I'm not personally aware of a library that happens to write out/read in, Intel Hex format from/to the EEPROM.



I have code that uploads and downloads files to the Arduino. Inside that is code to read/write Intel hex format. However it isn't a library.

Inside File_Utils.ino are some comments that show the format:

/*
Line format:

  :nnaaaatt(data)ss

  Where:
  :      = a colon

  (All of below in hex format)

  nn     = length of data part
  aaaa   = address (eg. where to write data)
  tt     = transaction type
           00 = data
           01 = end of file
           02 = extended segment address (changes high-order byte of the address)
           03 = start segment address *
           04 = linear address *
           05 = start linear address *
  (data) = variable length data
  ss     = sumcheck

            * We don't use these

*/




In that file is code to write Intel Hex format (reading from Flash, not EEPROM):

void readFlashContents ()
  {
  if (!haveSDcard)
    {
    Serial.println (F("*** No SD card detected."));
    return;
    }

  progressBarCount = 0;
  pagesize = currentSignature.pageSize;
  pagemask = ~(pagesize - 1);
  oldPage = NO_PAGE;
  byte lastMSBwritten = 0;

  while (true)
    {

    Serial.println ();  
    Serial.println (F("Choose file to save as: "));

    getline (name, sizeof name);
    int len = strlen (name);

    if (len &lt; 5 || strcmp (&amp;name [len - 4], ".HEX") != 0)
      {
      Serial.println (F("File name must end in .HEX"));  
      return;
      }

    // if file doesn't exist, proceed
    if (!sd.vwd()-&gt;exists (name))
      break;

    Serial.print (F("File "));
    Serial.print (name);    
    Serial.println (F(" exists. Overwrite? Type 'YES' to confirm ..."));  

    if (getYesNo ())
      break;

    }  // end of checking if file exists

  // ensure back in programming mode  
  if (!startProgramming ())
    return;  

  SdFile myFile;

  // open the file for writing
  if (!myFile.open(name, O_WRITE | O_CREAT | O_TRUNC)) 
    {
    Serial.print (F("Could not open file "));
    Serial.print (name);
    Serial.println (F(" for writing."));
    return;    
    }

  byte memBuf [16];
  bool allFF;
  unsigned int i;
  char linebuf [50];
  byte sumCheck;

  Serial.println (F("Copying flash memory to SD card (disk) ..."));  

  for (unsigned long address = 0; address &lt; currentSignature.flashSize; address += sizeof memBuf)
    {

    unsigned long thisPage = address &amp; pagemask;
    // page changed? show progress
    if (thisPage != oldPage &amp;&amp; oldPage != NO_PAGE)
      showProgress ();
    // now this is the current page
    oldPage = thisPage;

    // don't write lines that are all 0xFF
    allFF = true;

    for (i = 0; i &lt; sizeof memBuf; i++)
      {
      memBuf [i] = readFlash (address + i); 
      if (memBuf [i] != 0xFF)
        allFF = false;
      }  // end of reading 16 bytes
    if (allFF)
      continue;

    byte MSB = address &gt;&gt; 16;
    if (MSB != lastMSBwritten)
      {
      sumCheck = 2 + 2 + (MSB &lt;&lt; 4);
      sumCheck = ~sumCheck + 1;      
      // hexExtendedSegmentAddressRecord (02)
      sprintf (linebuf, ":02000002%02X00%02X\r\n", MSB &lt;&lt; 4, sumCheck);    
      myFile.print (linebuf);   
      lastMSBwritten = MSB;
      }  // end if different MSB

    sumCheck = 16 + lowByte (address) + highByte (address);
    sprintf (linebuf, ":10%04X00", (unsigned int) address &amp; 0xFFFF);
    for (i = 0; i &lt; sizeof memBuf; i++)
      {
      sprintf (&amp;linebuf [(i * 2) + 9] , "%02X",  memBuf [i]);
      sumCheck += memBuf [i];
      }  // end of reading 16 bytes

    // 2's complement
    sumCheck = ~sumCheck + 1;
    // append sumcheck
    sprintf (&amp;linebuf [(sizeof memBuf * 2) + 9] , "%02X\r\n",  sumCheck);

    myFile.clearWriteError ();
    myFile.print (linebuf);   
    if (myFile.getWriteError ())
       {
       Serial.println ();  // finish off progress bar
       Serial.println (F("Error writing file."));
       myFile.close ();
       return; 
       }   // end of an error

    }  // end of reading flash 

  Serial.println ();  // finish off progress bar
  myFile.print (":00000001FF\r\n");    // end of file record
  myFile.close ();  
  // ensure written to disk
  sd.vwd()-&gt;sync ();
  Serial.print (F("File "));
  Serial.print (name);
  Serial.println (F(" saved."));
  }  // end of readFlashContents




That should give you some tips about how to write out the file. Look in my code to see the reading code as well. However as I said, you don't necessarily have to use that format if you just want to manipulate the data yourself.