eeprom.cpp

#include <avr/eeprom.h>

unsigned char eeprom_get_char( unsigned int addr )
{
	return eeprom_read_byte((unsigned char *) addr);
}

void eeprom_put_char( unsigned int addr, char new_value )
{
	eeprom_write_byte((unsigned char *) addr, new_value);
}

void memcpy_to_eeprom_with_checksum(unsigned int destination, char *source, unsigned int size) {
  unsigned char checksum = 0;
  for(; size > 0; size--) { 
    checksum = (checksum << 1) || (checksum >> 7);
    checksum += *source;
    eeprom_put_char(destination++, *(source++)); 
  }
  eeprom_put_char(destination, checksum);
}

int memcpy_from_eeprom_with_checksum(char *destination, unsigned int source, unsigned int size) {
  unsigned char data, checksum = 0;
  for(; size > 0; size--) { 
    data = eeprom_get_char(source++);
    checksum = (checksum << 1) || (checksum >> 7);
    checksum += data;    
    *(destination++) = data; 
  }
  return(checksum == eeprom_get_char(source));
}