One is SPIFFS and the other one is LittleFS. There are two file systems for utilizing the onboard flash on the ESP8266. Even though the file system is stored on the same flash chip as the program, when a new sketch is programmed, it does not modify file system contents. Along with this, by using a file system, we can create files, folders and users have the control to rename or delete whatever they create. Whereas in flash memory, it is like a thumb drive (pen drive) which has far more reads and writes cycles than EEPROM. In EEPROM, data is stored as bytes, and hence, storing large amounts of data will be complex and the number of reads and writes is limited.

To understand EEPROM (or E 2PROM), consider it as something similar to the hard drive on a computer or you can refer to our previous projects and articles on EEPROM.īut boards like NodeMCU have a flash memory that is more advanced than EEPROMs. This data can be erased and rewritten electrically hence the name “Electrically Erasable Programmable Read-only memory”. Hence, data is written permanently and it won’t change unless the user decides to. Here, non-volatile means that the data won’t be lost as soon as the power supply is cut. It is a non-volatile memory where data is written. This problem persists in Arduino as well, but to solve this in Arduino, we use EEPROM. So, here, let’s learn how to overcome the problem with the help of LittleFS. If one is familiar with using firebase to fetch and update data to real-time databases, then it’s known that it’s an annoying problem that the data will be destroyed when the NodeMCU resets.

Esp8266 problem with wire library