FTP_Server_Teensy41 library 
How To Install Using Arduino Library Manager
Features
This FTP_Server_Teensy41 library is modified from Arduino-Ftp-Server library to support Teensy 4.x with QNEthernet, NativeEthernet or W5x00 using Ethernet_Generic Library, and currently SDFat2.
In the near future, any FS, such as PSRAM, S, (Q)SPI Flash, etc. will be supported.
Currently supported Boards
- Teensy 4.1 using QNEthernet, NativeEthernet or W5x00 with Ethernet_Generic Library and built-in SDCard, etc.
- Teensy 4.0 using W5x00 with Ethernet_Generic Library
Changelog
Releases v1.0.0
- Initial porting and coding for Teensy 4.1 using built-in QNEthernet, NativeEthernet or W5x00 with Ethernet_Generic Library
- Currently supporting only SD Card. Will add support to LittleFS, etc. in next releases
Examples
Debug Terminal Output Samples
1. FTP_Server_SDFAT2 on TEENSY 4.1 with QNEthernet
Following is debug terminal output when running example FTP_Server_SDFAT2 on Teensy4.1 using Built-in Ethernet and QNEthernet Library to demonstrate the operation of FTP Server and SD Card using SDFat2.
Starting FTP_Server_SDFAT2 on TEENSY 4.1 with QNEthernet
FTP_Server_Teensy41 v1.0.0
Initializing SD card...
Wiring is correct and a card is present.
Card type: SDHC
Volume type is FAT32
Volume size (Kbytes): 31452672
Volume size (Mbytes): 30715
===============================
SDCard Initialization : done.
test.txt 1048702 22:42 April 29, 2022
foo.txt 13 00:00 January 1, 1980
datalog.bin 41943040 00:00 January 1, 2022
index.htm 3810 22:50 April 29, 2022
mydatalog.txt 10 22:24 April 9, 2022
edit.htm.gz 4116 20:15 March 13, 2022
CanadaFlag_1.png 41214 20:15 March 13, 2022
CanadaFlag_2.png 8311 20:15 March 13, 2022
CanadaFlag_3.jpg 11156 20:15 March 13, 2022
favicon.ico 1150 22:54 April 29, 2022
graphs.js.gz 1971 20:15 March 13, 2022
CanadaFlag_2_1.png 8311 22:52 April 29, 2022
ESP_AT_WM_Lite.txt 1547 22:51 April 29, 2022
done!
=========== USE_QN_ETHERNET ===========
Initialize Ethernet using static IP => IP Address = 192.168.2.241
FTP Server Credentials => account = teensy4x, password = ftp_test
[FTP] Ftp server waiting for connection on port 21
[FTP] Client connected!
USER teensy4x
PASS ftp_test
[FTP] Authentication Ok. Waiting for commands.
SYST
DELE test.txt
PORT 192,168,2,30,169,133
[FTP] Data IP set to 192.168.2.30 , Data port set to 43397
LIST
DELE datalog.bin
PORT 192,168,2,30,135,195
[FTP] Data IP set to 192.168.2.30 , Data port set to 34755
LIST
PORT 192,168,2,30,165,55
[FTP] Data IP set to 192.168.2.30 , Data port set to 42295
LIST
PORT 192,168,2,30,206,193
[FTP] Data IP set to 192.168.2.30 , Data port set to 52929
RETR index.htm
[FTP] Sending index.htm
PORT 192,168,2,30,182,29
[FTP] Data IP set to 192.168.2.30 , Data port set to 46621
STOR index1.htm
[FTP] Receiving index1.htm
[FTP] Transfer completed in (ms) 250 , Speed (kbytes/s) 15
QUIT
[FTP] Disconnecting client
[FTP] Ftp server waiting for connection on port 21