JWan Wiki

LittleFS data are stored inside the Flash memory (not EEPROM) and has 1MB size.

To format:

#include <LittleFS.h>

void setup() {
  Serial.begin(115200);

  if (!LittleFS.begin()) {
    Serial.println("LittleFS Mount Failed");
    return;
  }

  Serial.println("Formatting LittleFS...");
  if (LittleFS.format()) {
    Serial.println("LittleFS formatted successfully");
  } else {
    Serial.println("Failed to format LittleFS");
  }
}

void loop() {
  // Your code here
}

Show basic info:

#include <Arduino.h>
#include <LittleFS.h>
#include "SSD1306Wire.h"
SSD1306Wire display(0x3c, D5, D6); // reversed!

void setup() {
  Serial.begin(115200);

  Serial.println();
  Serial.println();
  Serial.println();

  uint32_t chipId = ESP.getChipId();
  Serial.print("Chip ID: ");
  Serial.println(chipId);
  
  uint32_t flashSize = ESP.getFlashChipSize();
  Serial.print("Flash Chip Size: ");
  Serial.print(flashSize / 1024 / 1024);
  Serial.println(" MB");

  Serial.println();

  LittleFS.begin();

  FSInfo fs_info;
  LittleFS.info(fs_info);

  Serial.printf("Total size: %u bytes\n", fs_info.totalBytes);
  Serial.printf("Used size: %u bytes\n", fs_info.usedBytes);
  Serial.printf("Block size: %u bytes\n", fs_info.blockSize);
  Serial.printf("Page size: %u bytes\n", fs_info.pageSize);
  Serial.printf("Max open files: %u\n", fs_info.maxOpenFiles);
  Serial.printf("Max path length: %u\n", fs_info.maxPathLength);
}

void loop() {
  // Your code here
}

Show files and folders:

#include <LittleFS.h>

void listDir(fs::FS &fs, const char * dirname, uint8_t levels) {
  Serial.printf("Listing directory: %s\n", dirname);

  Dir dir = fs.openDir(dirname);
  while (dir.next()) {
    if (dir.isDirectory()) {
      Serial.print("  DIR : ");
      Serial.println(dir.fileName());
      if (levels) {
        listDir(fs, dir.fileName().c_str(), levels - 1);
      }
    } else {
      Serial.print("  FILE: ");
      Serial.print(dir.fileName());
      Serial.print("  SIZE: ");
      Serial.println(dir.fileSize());
    }
  }
}

void setup() {
  Serial.begin(115200);
  if (!LittleFS.begin()) {
    Serial.println("LittleFS Mount Failed");
    return;
  }
  listDir(LittleFS, "/", 0);
}

void loop() {
  // Your code here
}