stoune/ffat_test

FFAT on ESP32, platform

The simple and up to date example of using FAT FS on ESP32 and platfromio

How I tested

My hardware is LilyGO TTGO T-Display esp32 board. It's an ESP32-based board with 4MB of flash memory.

How to use FFAT?

1. Add to platfromio.ini board_build.filesystem = fatfs

2. Select the right partition layout option board_build.partitions = noota_3gffat.csv with some partition layout .csv. You may chose some predefined partition layout from ESP-IDF example. I used noota_3gffat.csv.

3. Create a data folder and put in the files that you want to upload to the board flash memory.

4. PlatformIO -> Board Configuration -> Build Filesystem Image (see image below)

5. PlatformIO -> Board Configuration -> Upload filesystem Image (see image below)

6. Add the includes:

#include "FS.h"
#include "FFat.h"

7. In setup method before using any FFat methods initialise and mount the FFat partition:

if(!FFat.begin(false)){ // Change to true if you want to format the partition on mount error
    Serial.println("An Error has occurred while mounting FFat");
    return;
  }

8. Read/Write/Append files. Open a file using the appropriate mode or combination:

// open file
  File file = FFat.open("/test.json", "r");
  if(!file){ // Don't forget to check if the file was opened successfully
    Serial.println("Failed to open test.json file for reading");
    return;
  }

9. File operation:

while(file.available()){
    Serial.write(file.read());
  }

10. Don't forget to close the file:

fileTmp.close();

Useful links and utilities

How to use custom partition tables on ESP32

FATFS on ESP32 - partly out of date, but the Arduino sketch will work if you need it.

Parttool

Parttool allows you to read and write partitions.

With installed to the default location Espressif ESP-IDF you will find partttol at(macos): $HOME/esp/esp-idf/components/partition_table

I set up IDF_PATH environment variable first: export $IDF_PATH=$HOME/esp/esp-idf

then I run parttool to read the FAT partitions into the ffat.bin file: ./parttool.py --port "/dev/tty.SLAB_USBtoUART" read_partition --partition-type=data --partition-subtype=fat --output "ffat.bin" , where /dev/tty.SLAB_USBtoUART is the USB serial port of the board.