Understanding how example code works about eeprom_rotate HOT 14 OPEN

/*
   EEPROM Write

   Stores random values into the EEPROM.
   These values will stay in the EEPROM when the board is
   turned off and may be retrieved later by another sketch.
*/

#include "EEPROM.h"

// the current address in the EEPROM (i.e. which byte
// we're going to write to next)
int addr = 0;
#define EEPROM_SIZE 64
void setup()
{
  Serial.begin(115200);
  Serial.println("start...");
  if (!EEPROM.begin(EEPROM_SIZE))
  {
    Serial.println("failed to initialise EEPROM"); delay(1000000);
  }

  Serial.print("Value in EEPROM 0 before writing =");
  Serial.println(EEPROM.read(0));
  Serial.println("Writing value 10 to EEPROM 0 address");
  EEPROM.write(0,10);
  EEPROM.commit();
  
  Serial.print("Value in EEPROM 0 after writing =");
  Serial.println(EEPROM.read(0));

  Serial.println("Writing value 19 to EEPROM 0 address");
  EEPROM.write(0,19);
  EEPROM.commit();
  
  Serial.print("Value in EEPROM 0 after second writing =");
  Serial.println(EEPROM.read(0));

  
}

void loop()
{
  // need to divide by 4 because analog inputs range from

}

esp32.menu.PartitionScheme.test=rotate_eeprom
esp32.menu.PartitionScheme.test.build.partitions=test
esp32.menu.PartitionScheme.test.upload.maximum_size=1310720

Traceback (most recent call last):
  File "gen_esp32part.py", line 524, in <module>
  File "gen_esp32part.py", line 471, in main
UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 0: ordinal not in range(128)
Failed to execute script gen_esp32part
exit status -1
Error compiling for board ESP32 Dev Module.

        EEPROM.writeUShort(eeprom_counter, item_inside.quantity);               // 2^16 - 1
        eeprom_counter += sizeof(unsigned short);
        Serial.print("address after quantity=");
        Serial.println(eeprom_counter);
        
        EEPROM.writeString(eeprom_counter, item_inside.serial);
        eeprom_counter = eeprom_counter + 10;
        Serial.print("address after string=");
        Serial.println(eeprom_counter);
        
        //UPDATE THE eeprom counter
        EEPROM.write(0,eeprom_counter);
        EEPROM.commit();

void initial_eeprom_values(){
  eeprom_counter = EEPROM.read(0);
  Serial.print("Initial eeprom values = ");
  Serial.println(eeprom_counter);
  if(eeprom_counter >= 12)
    prev_eeprom_counter = eeprom_counter -12;
    
  EEPROM.get(prev_eeprom_counter,item_inside.quantity);
  Serial.print("quantity inside initial=");
  Serial.println(item_inside.quantity);
  if(item_inside.quantity == 65535){
    item_inside.quantity=0;
  }
  
  prev_eeprom_counter += sizeof(unsigned short);
  EEPROM.get(prev_eeprom_counter,item_inside.serial);
  prev_eeprom_counter = prev_eeprom_counter +10;
  Serial.print("serial isnide initial=");
  Serial.println(item_inside.serial);
}

        int addr=0;  
        Serial.printf("[EEPROM] Current partition   : %s\n", EEPROMr.current());
        EEPROMr.writeUShort(addr, item_inside.quantity);               // 2^16 - 1
        addr += sizeof(unsigned short);
        Serial.print("Quantity written=");
        Serial.println(item_inside.quantity);
        
        EEPROMr.writeString(addr, item_inside.serial);
        Serial.print("Serial written=");
        Serial.println(item_inside.serial);

        EEPROMr.commit();

        addr=0;

        EEPROMr.get(addr,item_inside.quantity);
        Serial.print("quantity inside after write initial=");
        Serial.println(item_inside.quantity);

        addr += sizeof(unsigned short);
        EEPROMr.get(addr,item_inside.serial);
        Serial.print("serial inside after write=");
        Serial.println(item_inside.serial);
        
        ESP.restart();

void initial_eeprom_values(){
  int addr = 0;
  Serial.printf("[EEPROM] Current partition   : %s\n", EEPROMr.current());
 
    
  EEPROMr.get(addr,item_inside.quantity);
  Serial.print("quantity inside initial=");
  Serial.println(item_inside.quantity);
  
  if(item_inside.quantity == 65535){
    item_inside.quantity=0;
  }
  
  addr += sizeof(unsigned short);
  EEPROMr.get(addr,item_inside.serial);
  Serial.print("serial isnide initial=");
  Serial.println(item_inside.serial);
}