Listing 10 4 EEPROM setup

/*Listing 10-4. The setup() loop code

 Purpose: To write data to EEPROM memory.

  Dr. Purdum, December 22, 2014
 */
#include <EEPROM.h>
#define DEBUG 1                // We want to see debug print statements
                                 // Comment out to avoid seeing print statements
const int MAXPEOPLE = 10;
struct servicePeople {        // Structure definition for servicePeople
  int ID;
  char Name[20];
  char PW[10];
  long Phone;
};

union servicePeopleUnion {            // A union definition for myUnion
  byte temp[sizeof(int)];
  int testID;
  struct servicePeople testServicePeople;
} myUnion;

servicePeople myPeople[MAXPEOPLE] = {    // company data for testing
  {0, "This is a dummy","admin",5555555},
  {101,"Kack Lawn Service","Clowder",2345678},
  {222,"Jane's Plants","Noah",4202513},
  {333,"Terrys Pool Service","Billings",4301016}
};
// function declarations:
void DataDump(struct servicePeople temp);
int FindEepromTop();
int ReadIntFlag();
void ReadOneRecord(int index);
void WriteFirstRecord();

// Global Variables
int loopCounter = 0;               // Number of passes to make through loop
int initFlag = 0;                  // Has the EEPROM been initialized?
struct servicePeople temp;      // A temporary structure 

void setup()
{
// initFlag = -1;      // Remove comment at beginning of this
                         // line first time you run program.

  int eepromMax;
  int i;

  Serial.begin(9600);
  eepromMax = FindEepromTop();    // How much EEPROM?
#ifdef DEBUG
  Serial.print("EepromMax = ");
  Serial.println(eepromMax);
#endif
  initFlag = ReadIntFlag();  // Initialized?
  if (initFlag < 0) {
    for (i = 0; i < MAXPEOPLE; i++) {
        WriteOneRecord(i);
    }
  }
  initFlag = 1;  // Either way, EEPROM is initialized by now
}// END Setup
//-----------------------------------

// Listing 10-8. Source code for the loop() function 
void loop()
{
  static int eepromIndex = 1;  // Assume there are records

  loopCounter++;
  if (initFlag > 0) {  // There are records to read
    ReadOneRecord(eepromIndex++);
    if (myUnion.testServicePeople.ID != 0) { // Read some real data
       DataDump(myUnion.testServicePeople);
    }
  } else {
    eepromIndex++;  // Make sure loop can end with no records.
  }

#ifdef DEBUG
  Serial.println("==========");
#endif
  if (eepromIndex == MAXPEOPLE) {
    exit(1);
//    TerminationStep();
  }
}// END loop

//*******************************************************************

//-----------------------------------
//User defined functions


/*****
  Purpose: Find out how much EEPROM this board has. I
          
  Parameter list:
    void
    
  Return value:
    int          the EEPROM size       
   
    Free to use: econjack 
*****/
int FindEepromTop()
{
   return E2END + 1;
}



/*****
  Purpose: This function reads the int-sized bytes of EEPROM and
          returns the integer found there.
          
  Parameter list:
    void
    
  Return value:
    int          0 if no records in EEPROM, 1 if there are
*****/
int ReadIntFlag()
{
  int i;

  for (i = 0; i < sizeof(int); i++) {
    myUnion.temp[i] = EEPROM.read(i);
  }
  return myUnion.testID;
}


/*****
  Purpose: This function writes one record from the myPeople[] array
        to EEPROM
          
  Parameter list:
    int index      The element of the myPeople[] array to write
    
  Return value:
    void
*****/
void WriteOneRecord(int index)
{
  byte *b;
  int i;
  int offset = index * sizeof(servicePeople);

  b = (byte *) &myPeople[index];    // Going to write this record
  for (i = 0; i < sizeof(servicePeople); i++) {
    EEPROM.write(i + offset, *b++);
  }
}

// Listing 10-9. Source code for ReadOneRecord()
/*****
  Purpose: This function reads one servicePerson record from
        EEPROM
          
  Parameter list:
    int index    The element of the myPerson[] array to read
                from EEPROM
    
  Return value:
    void        
*****/
void ReadOneRecord(int index)
{
  byte *bPtr;
  int i;
  int offset;

  offset = index * sizeof(servicePeople);  // must offset from 0 in EEPROM

  bPtr = (byte *) &myUnion.testServicePeople;  // where to put the data read

  for (i = 0; i < sizeof(temp); i++) {  // Loop through the bytes...
    *bPtr = EEPROM.read(offset + i);
    bPtr++;
  }
}


// Listing 10-10. Source code for DataDump()
/*****
  Purpose: Sends the data stored in parameter to the serial monitor
          
  Parameter list:
    struct servicePeople temp    // The data to be displayed
    
  Return value:
    void        
*****/
void DataDump(struct servicePeople temp)
{

    Serial.println();
    Serial.print("ID = ");
    Serial.print(temp.ID);
    Serial.print("  Name = ");
    Serial.println(temp.Name);
    Serial.print("  PW = ");
    Serial.print(temp.PW);
    Serial.print("  Phone = ");
    Serial.println(temp.Phone);
}