LittleFS_Mbed_RP2040 Library

---

---

Table of Contents

• Important Notes
• Why do we need this LittleFS_Mbed_RP2040 library
  • Features
  • Currently supported Boards
• Changelog
• Prerequisites
• Installation
  • Use Arduino Library Manager
  • Manual Install
  • VS Code & PlatformIO
• Examples
  • 1. LittleFS_Counting
  • 2. LittleFS_Test
• Example LittleFS_Test
• Debug Terminal Output Samples
  • 1. LittleFS_Counting on RaspberryPi Pico
  • 2. LittleFS_Test on RaspberryPi Pico
• Debug
• Troubleshooting
• Issues
• TO DO
• DONE
• Contributions and Thanks
• Contributing
• License
• Copyright

---

---

Important Notes

The LittleFS of the new Nano_RP2040_Connect board (see picture below), using ISSI Flash chip, is currently not working with Arduino mbed_rp2040 core 2.4.1+. Please downgrade to Arduino mbed_rp2040 core 2.3.1

Check RP2040 Connect board has faulty components in newest purchase #318 for more information of when and how the issue will be fixed.

The old board (see picture below), using Adesto Flash chip, is currently working with Arduino mbed_rp2040 core 2.4.1+.

---

---

Why do we need this LittleFS_Mbed_RP2040 library

Features

This library is just a simple LittleFS wrapper to facilitate your usage of LittleFS for the onboard flash on MBED RP2040-based boards such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, using Arduino-mbed RP2040 core

The filesystem access uses normal POSIX APIs or mbed FileSystem APIs

---

Currently supported Boards

1. RP2040-based boards such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040, etc. using Arduino-mbed RP2040 core

---

---

Prerequisites

1. Arduino IDE 1.8.19+ for Arduino
2. Arduino mbed_rp2040 core 2.3.1- for RP2040-based boards using ISSI Flash chip, see New board, such as Arduino Nano RP2040 Connect, RASPBERRY_PI_PICO, etc..
3. Arduino mbed_rp2040 core 2.4.1+ for Arduino (Use Arduino Board Manager) RP2040-based boards using Adesto Flash chip, see Old board, such as Arduino Nano RP2040 Connect, RASPBERRY_PI_PICO, etc.. Latest release is

---

---

Installation

Use Arduino Library Manager

The best and easiest way is to use Arduino Library Manager. Search for LittleFS_Mbed_RP2040, then select / install the latest version. You can also use this link for more detailed instructions.

Manual Install

Another way to install is to:

1. Navigate to LittleFS_Mbed_RP2040 page.
2. Download the latest release LittleFS_Mbed_RP2040-main.zip.
3. Extract the zip file to LittleFS_Mbed_RP2040-main directory
4. Copy whole LittleFS_Mbed_RP2040-main folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO

1. Install VS Code
2. Install PlatformIO
3. Install LittleFS_Mbed_RP2040 library by using Library Manager. Search for LittleFS_Mbed_RP2040 in Platform.io Author's Libraries
4. Use included platformio.ini file from examples to ensure that all dependent libraries will installed automatically. Please visit documentation for the other options and examples at Project Configuration File

---

---

Examples

1. LittleFS_Counting
2. LittleFS_test

---

---

Example Littlefs_Test

LittleFS_Mbed_RP2040/examples/LittleFS_Test/LittleFS_Test.ino

Lines 11 to 359 in 088cf4b

	#define LFS_MBED_RP2040_VERSION_MIN_TARGET "LittleFS_Mbed_RP2040 v1.1.0"
	#define LFS_MBED_RP2040_VERSION_MIN 1001000
	#define _LFS_LOGLEVEL_ 1
	#define RP2040_FS_SIZE_KB 64
	#define FORCE_REFORMAT false
	#include <LittleFS_Mbed_RP2040.h>
	LittleFS_MBED *myFS;
	void readCharsFromFile(const char * path)
	{
	Serial.print("readCharsFromFile: ");
	Serial.print(path);
	FILE *file = fopen(path, "r");
	if (file)
	{
	Serial.println(" => Open OK");
	}
	else
	{
	Serial.println(" => Open Failed");
	return;
	}
	char c;
	while (true)
	{
	c = fgetc(file);
	if ( feof(file) )
	{
	break;
	}
	else
	Serial.print(c);
	}
	fclose(file);
	}
	void readFile(const char * path)
	{
	Serial.print("Reading file: ");
	Serial.print(path);
	FILE *file = fopen(path, "r");
	if (file)
	{
	Serial.println(" => Open OK");
	}
	else
	{
	Serial.println(" => Open Failed");
	return;
	}
	char c;
	uint32_t numRead = 1;
	while (numRead)
	{
	numRead = fread((uint8_t *) &c, sizeof(c), 1, file);
	if (numRead)
	Serial.print(c);
	}
	fclose(file);
	}
	void writeFile(const char * path, const char * message, size_t messageSize)
	{
	Serial.print("Writing file: ");
	Serial.print(path);
	FILE *file = fopen(path, "w");
	if (file)
	{
	Serial.println(" => Open OK");
	}
	else
	{
	Serial.println(" => Open Failed");
	return;
	}
	if (fwrite((uint8_t *) message, 1, messageSize, file))
	{
	Serial.println("* Writing OK");
	}
	else
	{
	Serial.println("* Writing failed");
	}
	fclose(file);
	}
	void appendFile(const char * path, const char * message, size_t messageSize)
	{
	Serial.print("Appending file: ");
	Serial.print(path);
	FILE *file = fopen(path, "a");
	if (file)
	{
	Serial.println(" => Open OK");
	}
	else
	{
	Serial.println(" => Open Failed");
	return;
	}
	if (fwrite((uint8_t *) message, 1, messageSize, file))
	{
	Serial.println("* Appending OK");
	}
	else
	{
	Serial.println("* Appending failed");
	}
	fclose(file);
	}
	void deleteFile(const char * path)
	{
	Serial.print("Deleting file: ");
	Serial.print(path);
	if (remove(path) == 0)
	{
	Serial.println(" => OK");
	}
	else
	{
	Serial.println(" => Failed");
	return;
	}
	}
	void renameFile(const char * path1, const char * path2)
	{
	Serial.print("Renaming file: ");
	Serial.print(path1);
	Serial.print(" to: ");
	Serial.print(path2);
	if (rename(path1, path2) == 0)
	{
	Serial.println(" => OK");
	}
	else
	{
	Serial.println(" => Failed");
	return;
	}
	}
	void testFileIO(const char * path)
	{
	Serial.print("Testing file I/O with: ");
	Serial.print(path);
	#define BUFF_SIZE 512
	static uint8_t buf[BUFF_SIZE];
	FILE *file = fopen(path, "w");
	if (file)
	{
	Serial.println(" => Open OK");
	}
	else
	{
	Serial.println(" => Open Failed");
	return;
	}
	size_t i;
	Serial.println("- writing" );
	uint32_t start = millis();
	size_t result = 0;
	// Write a file only 1/4 of RP2040_FS_SIZE_KB
	for (i = 0; i < RP2040_FS_SIZE_KB / 2; i++)
	{
	result = fwrite(buf, BUFF_SIZE, 1, file);
	if ( result != 1)
	{
	Serial.print("Write result = ");
	Serial.println(result);
	Serial.print("Write error, i = ");
	Serial.println(i);
	break;
	}
	}
	Serial.println("");
	uint32_t end = millis() - start;
	Serial.print(i / 2);
	Serial.print(" Kbytes written in (ms) ");
	Serial.println(end);
	fclose(file);
	printLine();
	/////////////////////////////////
	file = fopen(path, "r");
	start = millis();
	end = start;
	i = 0;
	if (file)
	{
	start = millis();
	Serial.println("- reading" );
	result = 0;
	fseek(file, 0, SEEK_SET);
	// Read file only 1/4 of RP2040_FS_SIZE_KB
	for (i = 0; i < RP2040_FS_SIZE_KB / 2; i++)
	{
	result = fread(buf, BUFF_SIZE, 1, file);
	if ( result != 1 )
	{
	Serial.print("Read result = ");
	Serial.println(result);
	Serial.print("Read error, i = ");
	Serial.println(i);
	break;
	}
	}
	Serial.println("");
	end = millis() - start;
	Serial.print((i * BUFF_SIZE) / 1024);
	Serial.print(" Kbytes read in (ms) ");
	Serial.println(end);
	fclose(file);
	}
	else
	{
	Serial.println("- failed to open file for reading");
	}
	}
	void printLine()
	{
	Serial.println("====================================================");
	}
	void setup()
	{
	Serial.begin(115200);
	while (!Serial)
	delay(1000);
	Serial.print("\nStart LittleFS_Test on ");
	Serial.println(BOARD_NAME);
	Serial.println(LFS_MBED_RP2040_VERSION);
	#if defined(LFS_MBED_RP2040_VERSION_MIN)
	if (LFS_MBED_RP2040_VERSION_INT < LFS_MBED_RP2040_VERSION_MIN)
	{
	Serial.print("Warning. Must use this example on Version equal or later than : ");
	Serial.println(LFS_MBED_RP2040_VERSION_MIN_TARGET);
	}
	#endif
	myFS = new LittleFS_MBED();
	if (!myFS->init())
	{
	Serial.println("LITTLEFS Mount Failed");
	return;
	}
	char fileName1[] = MBED_LITTLEFS_FILE_PREFIX "/hello1.txt";
	char fileName2[] = MBED_LITTLEFS_FILE_PREFIX "/hello2.txt";
	char message[] = "Hello from " BOARD_NAME "\n";
	printLine();
	writeFile(fileName1, message, sizeof(message));
	printLine();
	readFile(fileName1);
	printLine();
	appendFile(fileName1, message, sizeof(message));
	printLine();
	readFile(fileName1);
	printLine();
	renameFile(fileName1, fileName2);
	printLine();
	readCharsFromFile(fileName2);
	printLine();
	deleteFile(fileName2);
	printLine();
	readFile(fileName2);
	printLine();
	testFileIO(fileName1);
	printLine();
	testFileIO(fileName2);
	printLine();
	deleteFile(fileName1);
	printLine();
	deleteFile(fileName2);
	printLine();
	Serial.println( "\nTest complete" );
	}
	void loop()
	{
	}

---

---

Debug Terminal Output Samples

1. LittleFS_Counting on RaspberryPi Pico

The following is the sample terminal output when running example LittleFS_Counting on MBED RaspberryPi Pico

Start LittleFS_Counting on RaspberryPi Pico
LittleFS_Mbed_RP2040 v1.1.0
[LFS] LittleFS size (KB) = 256
[LFS] LittleFS Mount OK
Deleting file: /littlefs/counts.txt => OK
Times have been run = 1
 => Open to write OK

Start LittleFS_Counting on RaspberryPi Pico
LittleFS_Mbed_RP2040 v1.1.0
[LFS] LittleFS size (KB) = 256
[LFS] LittleFS Mount OK
 => Open to read OK
Times have been run = 2
 => Open to write OK

Start LittleFS_Counting on RaspberryPi Pico
LittleFS_Mbed_RP2040 v1.1.0
[LFS] LittleFS size (KB) = 256
[LFS] LittleFS Mount OK
 => Open to read OK
Times have been run = 3
 => Open to write OK

---

2. LittleFS_Test on RaspberryPi Pico

The following is the sample terminal output when running example LittleFS_Test on MBED RaspberryPi Pico

Start LittleFS_Test on RaspberryPi Pico
LittleFS_Mbed_RP2040 v1.1.0
[LFS] LittleFS size (KB) = 256
[LFS] LittleFS Mount OK
====================================================
Writing file: /littlefs/hello1.txt => Open OK
* Writing OK
====================================================
Reading file: /littlefs/hello1.txt => Open OK
Hello from RaspberryPi Pico
====================================================
Appending file: /littlefs/hello1.txt => Open OK
* Appending OK
====================================================
Reading file: /littlefs/hello1.txt => Open OK
Hello from RaspberryPi Pico
Hello from RaspberryPi Pico
====================================================
Renaming file: /littlefs/hello1.txt to: /littlefs/hello2.txt => OK
====================================================
readCharsFromFile: /littlefs/hello2.txt => Open OK
Hello from RaspberryPi Pico
Hello from RaspberryPi Pico
====================================================
Deleting file: /littlefs/hello2.txt => OK
====================================================
Reading file: /littlefs/hello2.txt => Open Failed
====================================================
Testing file I/O with: /littlefs/hello1.txt => Open OK
- writing

64 Kbytes written in (ms) 847
====================================================
- reading

64 Kbytes read in (ms) 18
====================================================
Testing file I/O with: /littlefs/hello2.txt => Open OK
- writing

64 Kbytes written in (ms) 847
====================================================
- reading

64 Kbytes read in (ms) 18
====================================================
Deleting file: /littlefs/hello1.txt => OK
====================================================
Deleting file: /littlefs/hello2.txt => OK
====================================================

Test complete

---

---

Debug

Debug is enabled by default on Serial.

You can also change the debugging level (LFS_LOGLEVEL) from 0 to 4

#define LFS_DEBUG_OUTPUT    Serial

// These define's must be placed at the beginning before #include "LittleFS_Mbed_RP2040.h"
// _LFS_LOGLEVEL_ from 0 to 4
#define _LFS_LOGLEVEL_      0

---

Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of the core for Arduino boards.

Sometimes, the library will only work if you update the board core to the latest version because I am using newly added functions.

---

---

Issues

Submit issues to: LittleFS_Mbed_RP2040 issues

---

TO DO

1. Search for bug and improvement.

---

DONE

1. Basic LittleFS wrapper for RP2040-based boards such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, using Arduino-mbed RP2040 core
2. Add Version String
3. Add Table of Contents
4. Add astyle using allman style. Restyle the library

---

---

Contributions and Thanks

Many thanks for everyone for bug reporting, new feature suggesting, testing and contributing to the development of this library.

1. Thanks to Maximilian Gerhardt to create bug report RP2040_RTC_Time crashes Pico, does not work #3 and help investigate and fix the bug, leading to v1.0.3

Maximilian Gerhardt

---

Contributing

If you want to contribute to this project:

• Report bugs and errors
• Ask for enhancements
• Create issues and pull requests
• Tell other people about this library

---

License

• The library is licensed under GPLv3

---

Copyright

Copyright (c) 2021- Khoi Hoang