LwFTP Client

A lightweight FTP client using FreeRTOS and the Netconn API from LwIP, designed for STM32 H7.

About The Project

This project aims to provide a simple FTP client for embedded systems, enabling file operations over a network. It's built for systems running FreeRTOS and uses the Netconn API from LwIP for network communication.

Prerequisites:

• STM32 H7 microcontroller
• An FTP Server (tested with Windows IIS Server Manager)
• FreeRTOS
• LwIP with Netconn API (requires RTOS mode)
• This repository

Initialization

To initialize the LwFTP client, follow these steps:

1. Add the following declarations in the /* USER CODE BEGIN PV */ sections

   /* USER CODE BEGIN PV */
   static lwftp_session_t s;
   uint8_t CLI_IP[4] = { 192, 168, 0, 120 };    // Client IP address
   uint8_t SVR_IP[4] = { 192, 168, 0, 100 };    // Server IP address
   u16_t SVR_PORT = 21;                         // FTP server port, typically 21
   char *USER = "anonymous";                    // FTP login username
   char *PASS = "email@example.com";            // FTP login password
   /* USER CODE END PV */
   

2. Declare lwftp_init() in the main file

   example:

   void lwftp_init(void) {
       IP4_ADDR(&s.cli_ip, CLI_IP[0], CLI_IP[1], CLI_IP[2], CLI_IP[3]);
       IP4_ADDR(&s.svr_ip, SVR_IP[0], SVR_IP[1], SVR_IP[2], SVR_IP[3]);
       s.svr_port = SVR_PORT;
       s.user = USER;
       s.pass = PASS;
   
       debugPrint("\n>> lwftp: cli ip: %d.%d.%d.%d\r\n", CLI_IP[0], CLI_IP[1], CLI_IP[2], CLI_IP[3]);
       debugPrint(">> lwftp: svr ip: %d.%d.%d.%d\r\n", SVR_IP[0], SVR_IP[1], SVR_IP[2], SVR_IP[3]);
       debugPrint(">> lwftp: svr port: %d\r\n", s.svr_port);
       debugPrint(">> lwftp: username: %s\r\n", s.user);
       debugPrint(">> lwftp: password: %s\r\n\n", s.pass);
   
       // Initialize threads for FTP connections
       sys_thread_new("lwftp_ctrl_thread", lwftp_ctrl_thread, (void*) &s, DEFAULT_THREAD_STACKSIZE, osPriorityNormal);
       sys_thread_new("lwftp_data_thread", lwftp_data_thread, (void*) &s, DEFAULT_THREAD_STACKSIZE, osPriorityNormal);
   }
   

3. Call lwftp_init() from the user code area of StartDefaultTask() in main.c, right after MX_LWIP_Init()

   example:

   void StartDefaultTask(void const * argument)
   {
       /* init code for LWIP */
       MX_LWIP_Init();
       /* USER CODE BEGIN 5 */
       lwftp_init();
       /* Infinite loop */
       for (;;) {
           osDelay(1);
       }
       /* USER CODE END 5 */
   }
   

Main Features & Limitations

• Storing Files: err = lwftp_store(&s, <filename.extension>, <data>);

  • Under development: A feature to prevent overwriting duplicate files.

• Retrieving Files: err = lwftp_retrieve(&s, <filename.extension>);

  • Limitation: May omit excessively long content. This issue is pending resolution.

• Listing Files: err = lwftp_list(&s, fileList);

  • To retrieve a list of files from the server's root directory, declare a character array (e.g., char *fileList[500];) and pass it as an argument.
  • Note: Path specification is not implemented.
  • Note: The output format of the file list may vary between servers, requiring careful parsing.

• Closing Connection: err = lwftp_close(&s);

  • closes the FTP connection.

Features for debugging

• Enabling LwFTP Debugging Output

  To enable verbose debugging output for LwFTP, modify the LWFTP_DEBUG comment value in lwftp.h.