EEPROM Rotation for ESP8266 and ESP32
The Arduino Core for ESP8266 and ESP32 uses one SPI flash memory sector to emulate an EEPROM. When you initialize the EEPROM object (calling begin) it reads the contents of the sector into a memory buffer. Reading a writing is done over that in-memory buffer. Whenever you call commit it write the contents back to the flash sector. Due to the nature of this flash memory (NOR) a full sector erase must be done prior to write any new data....