zenz/LITTLEFS

LittleFS library for arduino-esp32

LittleFS_esp32

Ths library is now part of Arduino esp32 core v2

Note, there it is renamed from LITTLEFS to LittleFS, Please post your issues there. This here is kept for Arduino esp32 core 1.x purposes

LittleFS library for arduino-esp32

• A LittleFS wrapper for Arduino ESP32 of littlefs-project
• Based on ESP-IDF port of joltwallet/esp_littlefs , thank you Brian!
• As a reference, see LillteFS library for ESP8266 core
• PR and merge at esp32 core development
• PR at esp-idf development
• The functionality is similar to SPIFFS

Installation

• Use Arduino Library Manager
• Or download / use git to have latest repository of LITTLEFS added to Arduino IDE /libraries folder
  (File > Preferences > Sketchbook location).
• See #define CONFIG_LITTLEFS_FOR_IDF_3_2 in esp_littlefs.c.
  Now it is defined / undefined automatically by detecting the IDF version and core version. When defined, the library works with old and new IDFs 3.2 - 4.x but file timestamp feature is removed. See LITTLEFS_time example.
• See #define CONFIG_LITTLEFS_SPIFFS_COMPAT in esp_littlefs.c.
  When set to 1, folders are recursively created or deleted if empty on creating/deleting a new file like SPIFFS. Default is 0.
• The other #define CONFIG_LITTLEFS_xxxxx are set to optimal default values.
  Read here and here if you want to modify.
• For low-level default error reporting modifications, see the defines at beginning of the lfs.c here.

Usage

• Use LITTLEFS with identical methods as SPIFFS plus mkdir() and rmdir()
• A quick startup based on your existing code you can re-define SPIFFS

#define USE_LittleFS

#include <FS.h>
#ifdef USE_LittleFS
  #define SPIFFS LITTLEFS
  #include <LITTLEFS.h> 
#else
  #include <SPIFFS.h>
#endif 

• Note, this may not work if your sketch uses other libraries that use SPIFFS themselves.
• See also esp_partition.h . LITTLEFS re-uses same type and subtype as SPIFFS

Differences with SPIFFS

• LittleFS has folders, you need to iterate files in folders unless you set #define CONFIG_LITTLEFS_SPIFFS_COMPAT 1
• At root a "/folder" = "folder"
• Requires a label for mount point, NULL will not work. Recommended is to use default LITTLEFS.begin()
• maxOpenFiles parameter is unused, kept for compatibility
• LITTLEFS.mkdir(path) and LITTLEFS.rmdir(path) are available
• file.seek() behaves like on FFat see more details
• file.write() and file.print() when partition space is ending may return different than really written bytes (on other FS is also inconsistent).
• Speed comparison based on LittleFS_test.ino sketch (for a file 1048576 bytes):

Filesystem	Read time [ms]	Write time [ms]
FAT	276	14493
LITTLEFS	446*	16387
SPIFFS	767	65622

*The read speed improved by changing #define CONFIG_LITTLEFS_CACHE_SIZE from 128 to 512

Arduino ESP32 LittleFS filesystem upload tool

• Use (replace if exists) arduino-esp32fs-plugin with this variant, which supports SPIFFS, LittleFS and FatFS
• Requires mklittlefs executable which is available in releases section here or download the zipped binary here or from esp-quick-toolchain releases here
• Copy it to /tools folder of esp32 platform where espota and esptool (.py or.exe) tools are located
• Restart Arduino IDE.

PlatformIO

• See LITTLEFS_PlatformIO example here
  ( based on notes below from BlueAndi )

• Add to platformio.ini: extra_scripts = replace_fs.py

• Add replace_fs.py to project root directory (where platformio.ini is located):

Import("env")
print("Replace MKSPIFFSTOOL with mklittlefs.exe")
env.Replace (MKSPIFFSTOOL = "mklittlefs.exe")

• Add mklittlefs.exe to project root directory as well.

Credits and license

• This work is based on littlefs-project , ESP-IDF port of joltwallet/esp_littlefs , Espressif Arduino core for the ESP32, the ESP-IDF - SPIFFS Library
• Licensed under GPL v2 (text)

To Do

• Submit to be added to Arduino Library Manager
• Optional drop-in compatibility with SPIFFS' lack of folders, similar to esp8266' way - implemented as a choice by a #define
  • recursive folders auto creation when a new file is created at non-existing path
  • recursive folders auto deletion on "last file" deletion (SPIFFS cannot have "folder w/o file")
  • review other differences: opendir(), rmdir(), unlink()
• Retire this library when released by esp32 Arduino core
• Cleanup examples