esp-idf-ftpServer

FTP Server for esp-idf using FAT file system.
I found this information.
So, I ported from here.
Since it uses the FAT file system instead of SPIFFS, directory operations are possible.
Also, compared to SPIFFS, writing is about three times faster.

Software requirements

ESP-IDF V4.4/V5.x.
ESP-IDF V5.0 is required when using ESP32-C2.
ESP-IDF V5.1 is required when using ESP32-C6.

Installation

git clone https://github.com/nopnop2002/esp-idf-ftpServer
cd esp-idf-ftpServer/
idf.py set-target {esp32/esp32s2/esp32s3/esp32c2/esp32c3/esp32c6}
idf.py menuconfig
idf.py flash monitor

If you need more storage space on FLASH, you need to modify partitions_example.csv.

Partition table

# Name,   Type, SubType, Offset,  Size, Flags
# Note: if you have increased the bootloader size, make sure to update the offsets to avoid overlap
nvs,      data, nvs,     0x9000,  0x6000,
phy_init, data, phy,     0xf000,  0x1000,
factory,  app,  factory, 0x10000, 1M,
storage,  data, fat,            , 0xF0000,  ---> This is for FAT file system

If your ESP32 has 4M Flash, you can get more space by changing this.
The maximum partition size of the FAT file system that can be specified on the 4M Flash model is 0x2F0000 (=2,960K).

Configuration

File System Selection

ESP32 supports the following file systems.
You can select any one using menuconfig.

• FAT file system on FLASH
• FAT file system on SPI peripheral SDCARD
• FAT file system on SDMMC peripheral SDCARD(Valid only for ESP32/ESP32S3)
• FAT file system on SPI Flash Memory like Winbond W25Q64(Not supported in this project)
• FAT file system on USB Memory Stick(Not supported in this project)

Besides this, the ESP32 supports the SPIFFS filesystem, but I don't use it because it can't handle directories.

When using MMC SDCARD, you can select 1 Line mode or 4 Line mode.

Note:
The connection when using SDSPI, SDMMC will be described later.

WiFi Setting for Station-MODE

You can connect using the mDNS hostname instead of the IP address.

You can use static IP.

WiFi Setting for AccessPoint-MODE

Using mDNS hostname

• esp-idf V4.4
  If you set CONFIG_MDNS_STRICT_MODE = y in sdkconfig.defaults, the firmware will be built with MDNS_STRICT_MODE.
  If MDNS_STRICT_MODE is not set, mDNS name resolution will not be possible after long-term operation.
• esp-idf V4.4.1
  mDNS component has been updated.
  If you set CONFIG_MDNS_STRICT_MODE = y in sdkconfig.defaults, the firmware will be built with MDNS_STRICT_MODE.
  Even if MDNS_STRICT_MODE is set, mDNS name resolution will not be possible after long-term operation.
• esp-idf V5.0 or later
  mDNS component has been updated.
  Long-term operation is possible without setting MDNS_STRICT_MODE.
  The following lines in sdkconfig.defaults should be removed before menuconfig.
  CONFIG_MDNS_STRICT_MODE=y

FTP Server Setting

Using FAT file system on SPI peripheral SDCARD

You can change it to any pin using menuconfig.

Note:
This project doesn't utilize card detect (CD) and write protect (WP) signals from SD card slot.

Using FAT file system on SDMMC peripheral SDCARD

On ESP32, SDMMC peripheral is connected to specific GPIO pins using the IO MUX.
GPIO pins cannot be customized.
GPIO2 and GPIO12 cannot be changed.
So using 4-line SD mode with ESP32 is very tricky.
Please see the table below for the pin connections.

On ESP32-S3, SDMMC peripheral is connected to GPIO pins using GPIO matrix.
This allows arbitrary GPIOs to be used to connect an SD card.

Note about GPIO2 (ESP32 only)

GPIO2 pin is used as a bootstrapping pin, and should be low to enter UART download mode. One way to do this is to connect GPIO0 and GPIO2 using a jumper, and then the auto-reset circuit on most development boards will pull GPIO2 low along with GPIO0, when entering download mode.

• Some boards have pulldown and/or LED on GPIO2. LED is usually ok, but pulldown will interfere with D0 signals and must be removed. Check the schematic of your development board for anything connected to GPIO2.

Note about GPIO12 (ESP32 only)

GPIO12 is used as a bootstrapping pin to select output voltage of an internal regulator which powers the flash chip (VDD_SDIO). This pin has an internal pulldown so if left unconnected it will read low at reset (selecting default 3.3V operation). When adding a pullup to this pin for SD card operation, consider the following:

• For boards which don't use the internal regulator (VDD_SDIO) to power the flash, GPIO12 can be pulled high.
• For boards which use 1.8V flash chip, GPIO12 needs to be pulled high at reset. This is fully compatible with SD card operation.
• On boards which use the internal regulator and a 3.3V flash chip, GPIO12 must be low at reset. This is incompatible with SD card operation.
  • In most cases, external pullup can be omitted and an internal pullup can be enabled using a gpio_pullup_en(GPIO_NUM_12); call. Most SD cards work fine when an internal pullup on GPIO12 line is enabled. Note that if ESP32 experiences a power-on reset while the SD card is sending data, high level on GPIO12 can be latched into the bootstrapping register, and ESP32 will enter a boot loop until external reset with correct GPIO12 level is applied.
  • Another option is to burn the flash voltage selection efuses. This will permanently select 3.3V output voltage for the internal regulator, and GPIO12 will not be used as a bootstrapping pin. Then it is safe to connect a pullup resistor to GPIO12. This option is suggested for production use.

Using long file name support

By default, FATFS file names can be up to 8 characters long.
If you use filenames longer than 8 characters, you need to change the values below.

Long File Name on FLASH.

Long File Name on SDCARD.

Short File Name on SDCARD

Limitations

• The server does not support multiple connections.
• The server does not support active connection.
  Only passive connections are supported.
  Unfortunately, Windows standard ftp.exe does not allow passive mode (PASV) connections.
  If you have to make a passive mode connection On Windows, you need to use another software such as FFFTP / WinSCP / FileZilla to connect in passive mode.
• The server can only process these commands.
  • SYST
  • CDUP
  • CWD
  • PWD
  • XPWD(Same as PWD)
  • SIZE
  • MDTM(Always GMT)
  • TYPE
  • USER
  • PASS
  • PASV
  • LIST
  • RETR
  • STOR
  • DELE
  • RMD
  • MKD
  • RNFR(Rename From)
  • RNTO(Rename To)
  • NOOP
  • QUIT
  • APPE
  • NLST

Using LilyGo ESP32-S2

The LilyGo ESP32-S2 development board has a micro SD card slot on the board.
It is connected to the ESP32 by SPI, and the peripheral power is supplied from GPIO14.
With this, you can easily build an FTP server.
No equipment other than the development board is required.
It works very stably.

Windows ftp client

I tested these client.
You need to set the connection type to Passive Mode.

• WinSCP
  

• FileZilla
  You need to make this setting when using FileZilla.

• FFFTP
  

Troubleshooting

I sometimes get this error when using external SPI SD card readers.
Requires a PullUp resistor.

You can see all the logging on the server side by commenting it out here.

void ftp_task (void *pvParameters)
{
  ESP_LOGI(FTP_TAG, "ftp_task start");
  //esp_log_level_set(FTP_TAG, ESP_LOG_WARN); ------------> Comment out
  strcpy(ftp_user, CONFIG_FTP_USER);
  strcpy(ftp_pass, CONFIG_FTP_PASSWORD);
  ESP_LOGI(FTP_TAG, "ftp_user:[%s] ftp_pass:[%s]", ftp_user, ftp_pass);

Reference

https://github.com/nopnop2002/esp-idf-ftpClient