ESP32 FTP problems (AppendFile function)

Question

By running the code below you are able to connect to the remote FTP server (NAS QNAP TS-251, QuFTP Service 1.3.1) and create the file by writing to it. After closing the file if you want to add text I go to use the AppendFile() function and then the Write() function and both give this error on the serial of ESP32:

FTP error: 425 Unable to build data connection: Connection refused

Code used

#include "Arduino.h"
#include <WiFi.h>
#include <WiFiClient.h> 
#include <ESP32_FTPClient.h>

const char* ssid = "";
const char* password = "";

char ftp_server[] = "";
char ftp_user[]   = "";
char ftp_pass[]   = "";

ESP32_FTPClient ftp (ftp_server,ftp_user,ftp_pass);

void setup()
{
  Serial.begin( 115200 );

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connessione Wi-Fi in corso...");
  }
  Serial.println("");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  Serial.print("\nMax Free Heap: ");
  Serial.println(ESP.getMaxAllocHeap());
  Serial.println("");

  ftp.OpenConnection();

  //Change directory
  ftp.ChangeWorkDir("/Web/W.Station/Data/");

  ftp.InitFile("Type A");
  ftp.NewFile("helloworld.txt");
  ftp.Write("Hi, I'm a new file");
  ftp.CloseFile();


  ftp.AppendFile("helloworld.txt");
  ftp.Write("\nWriting with AppendFile");
  ftp.CloseFile();
  ftp.CloseConnection();
}

Server log

What I expect What I expect is that by using the AppendFile function I can like "reopen" the file and then use the Write function to add the text to the file. I don't know if I'm getting the functions wrong, but searching the web one can find really little documentation on the subject.

Answer 1

Thanks for the reply Martin Prikryl, with the library "ESP32_FTPClient.h" it was still giving me some problems with communication even putting "InitFile" before the append. So I tried to change library and switched to a more generic one and it works great with this one.

Working code

#include "Arduino.h"
#include <WiFi.h>
#include <WiFiClient.h> 

#include <FTPClient_Generic.h>

const char* ssid = "";
const char* password = "";

char ftp_server[] = "";

char ftp_user[]   = "";
char ftp_pass[]   = "";

char dirName[]    = "/Web/W.Station/Data/";
char fileName[] = "helloworld.txt";

FTPClient_Generic ftp (ftp_server, ftp_user, ftp_pass, 60000);

void setup() {
  Serial.begin( 115200 );




  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connessione Wi-Fi in corso...");
  }
  Serial.println("");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());






  Serial.print("Max Free Heap: ");
  Serial.println(ESP.getMaxAllocHeap());






  ftp.OpenConnection();

  //Change directory
  ftp.ChangeWorkDir(dirName);

  Serial.println("Creating new file helloworld.txt");

  // Create a new file to use as the download example below:
  ftp.InitFile(COMMAND_XFER_TYPE_ASCII);
  ftp.NewFile(fileName);

  String textContent = String("Hi, I'm a new ASCII file created");

  ftp.Write(textContent.c_str());
  ftp.CloseFile();






  ftp.InitFile(COMMAND_XFER_TYPE_ASCII);
  ftp.AppendFile(fileName);

  textContent = String("\nAdded text");

  ftp.Write(textContent.c_str());
  ftp.CloseFile();

  ftp.CloseConnection();

}

void loop() {}