Simple FTP Server library Wio terminal with status display

I receive this device from SeeedStudio, and I find It very usefully. The first thing I thought about doing with this device was porting my SimpleFTPServer library.

Wio Terminal FTP Server with TFT monitor main

About Seeed Studio

Seeed is the IoT hardware enabler providing services over 10 years that empower makers to realize their projects and products. Seeed offers a wide array of hardware platforms and sensor modules ready to be integrated with existing IoT platforms and one-stop PCB manufacturing and Prototype PCB Assembly. Seeed Studio provides a wide selection of electronic parts including Arduino, Raspberry Pi and many different development board platforms. Especially the Grove Sytsem help engineers and makers to avoid jumper wires problems. Seeed Studio has developed more than 280 Grove modules covering a wide range of applications that can fulfill a variety of needs.

Wio Terminal

I hope you want read the introduction article about this device here “Wio Terminal: pinout, specs and Arduino IDE configurations”.

Wio Terminal is a complete system, compared to a normal development board it is equipped with screen + development board + input / output interface + container, which makes it an efficient product and ready for the final product.

You can find the device here on SeeedStudio Aliexpress

Link to high resolution pinout image

Library

You can find the library here on GitHub. I don’t already integrate It on Arduino IDE Library manger, but I think I do that soon.

I already write something about that on this article “FTP server on esp8266 and esp32” when I integrate esp32 and esp8266.

Click the DOWNLOADS button in the top right corner, rename the uncompressed folder SimpleFTPServer.

Check that the SimpleFTPServer contains FtpServer.cpp, FtpServer.h, FtpServerKey.h e SimpleFTPServer.h.

Place the SimpleFTPServer library folder your /libraries/ folder.

You may need to create the libraries subfolder if its your first library.

Restart the IDE.

You must set the correct environment by editing the lines in the FtpServerKey.h file.

#define DEFAULT_FTP_SERVER_NETWORK_TYPE_SAMD NETWORK_SEEED_RTL8720DN
#define DEFAULT_STORAGE_TYPE_SAMD STORAGE_SDFAT2

As you can see I don’t use the Seeed library to manage SD because exist an unresolved bug on It that generate a lot of scope problem.

But with this configuration, and the library SdFat, works properly.

How to

Create minimal FTP server

After download properly the library you can create a simple FTP server with few line of code.

You need to import all these libraries:

• Adafruit_ZeroDMA
• SdFat
• Seeed_Arduino_FreeRTOS
• Seeed_Arduino_FS
• Seeed_Arduino_mbedtls
• Seeed_Arduino_rpcUnified
• Seeed_Arduino_rpcWiFi
• Seeed_Arduino_SFUD
• SimpleFTPServer
• SPI

Here the complete sketch.

/*
* FtpServer Wio Terminal with SdFat library
*
* AUTHOR:  Renzo Mischianti
*
* https://www.mischianti.org/2021/07/01/simple-ftp-server-library-now-with-support-for-wio-terminal-and-sd/*
*/
#include "SdFat.h"
#include <rpcWiFi.h>
#include <FtpServer.h>
#define SD_CONFIG SdSpiConfig(SDCARD_SS_PIN, 2)
SdFs sd;
FtpServer ftpSrv;
const char *ssid = "<YOUR-SSID>";
const char *password = "<YOUR-PASSWD>";
void setup()
{
Serial.begin(115200);
delay(1000);
pinMode(5, OUTPUT);
digitalWrite(5, HIGH);
Serial.print("Starting SD.");
// Initialize the SD.
if (!sd.begin(SD_CONFIG)) {
sd.initErrorHalt(&Serial);
}
FsFile dir;
FsFile file;
// Open root directory
if (!dir.open("/")){
Serial.println("dir.open failed");
}
Serial.println("finish!");
// We start by connecting to a WiFi network
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.print(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED)
{
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
Serial.print(".");
delay(500);
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
delay(1000);
ftpSrv.begin("wioterminal","wioterminal");    //username, password for ftp.
}
void loop(void) {
ftpSrv.handleFTP();        //make sure in loop you call handleFTP()!!
}

Now you can connect to the terminal via FTP, check the configuration of the FTP client in the relative chapter.

Here the serial output.

Connecting to <YOUR-SSID>
WiFi connected
IP address:
192.168.1.176

Add a status callback to your FTP Server

The library offer the opportunity to add some callback to check the state of connection or transfer.

The signs of the functions are:

void (*_callback)(FtpOperation ftpOperation, unsigned int freeSpace, unsigned int totalSpace){};
void (*_transferCallback)(FtpTransferOperation ftpOperation, const char* name, unsigned int transferredSize){};

Main callback

The first is called when one of these operation is executed:

• FTP_CONNECT: a connection is established;
• FTP_DISCONNECT: client is disconnected;
• FTP_FREE_SPACE_CHANGE: free space is changed.

The other parameters are:

• freeSpace: space available on SD;
• totalSpace: total space of SD.

Transfer callback

The second one when these operation are executed:

• FTP_UPLOAD_START: when an upload is started;
• FTP_UPLOAD: when an upload is in course;
• FTP_DOWNLOAD_START: when download is started;
• FTP_DOWNLOAD: when a download is in course;
• FTP_DOWNLOAD_STOP or FTP_TRANSFER_STOP: when download is finished;
• FTP_UPLOAD_STOP or FTP_TRANSFER_STOP: when upload is finished;
• FTP_DOWNLOAD_ERROR or FTP_TRANSFER_ERROR: when a download error is occured;
• FTP_UPLOAD_ERROR or FTP_TRANSFER_ERROR: when an upload error is occured.

The other parameters are:

• name: the name of the file;
• transferredSize: the size transferred.

Example sketch with callback

The resulting code with callbacks can be:

/*
* FtpServer Wio Terminal with SdFat library
* and with callbacks to the main actions of FTP server
*
* AUTHOR:  Renzo Mischianti
*
* https://www.mischianti.org/2021/07/01/simple-ftp-server-library-now-with-support-for-wio-terminal-and-sd/
*
*/
#include "SdFat.h"
#include <rpcWiFi.h>
#include <FtpServer.h>
#define SD_CONFIG SdSpiConfig(SDCARD_SS_PIN, 2)
SdFs sd;
FtpServer ftpSrv;
const char *ssid = "reef-casa-sopra";
const char *password = "aabbccdd77";
void _callback(FtpOperation ftpOperation, unsigned int freeSpace, unsigned int totalSpace){
Serial.print(">>>>>>>>>>>>>>> _callback " );
Serial.print(ftpOperation);
/* FTP_CONNECT,
* FTP_DISCONNECT,
* FTP_FREE_SPACE_CHANGE
*/
Serial.print(" ");
Serial.print(freeSpace);
Serial.print(" ");
Serial.println(totalSpace);
};
void _transferCallback(FtpTransferOperation ftpOperation, const char* name, unsigned int transferredSize){
Serial.print(">>>>>>>>>>>>>>> _transferCallback " );
Serial.print(ftpOperation);
/* FTP_UPLOAD_START = 0,
* FTP_UPLOAD = 1,
*
* FTP_DOWNLOAD_START = 2,
* FTP_DOWNLOAD = 3,
*
* FTP_TRANSFER_STOP = 4,
* FTP_DOWNLOAD_STOP = 4,
* FTP_UPLOAD_STOP = 4,
*
* FTP_TRANSFER_ERROR = 5,
* FTP_DOWNLOAD_ERROR = 5,
* FTP_UPLOAD_ERROR = 5
*/
Serial.print(" ");
Serial.print(name);
Serial.print(" ");
Serial.println(transferredSize);
};
void setup()
{
Serial.begin(115200);
delay(1000);
pinMode(5, OUTPUT);
digitalWrite(5, HIGH);
Serial.print("Starting SD.");
// Initialize the SD.
if (!sd.begin(SD_CONFIG)) {
sd.initErrorHalt(&Serial);
}
FsFile dir;
FsFile file;
// Open root directory
if (!dir.open("/")){
Serial.println("dir.open failed");
}
Serial.println("finish!");
// We start by connecting to a WiFi network
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.print(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED)
{
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
Serial.print(".");
delay(500);
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
delay(1000);
ftpSrv.setCallback(_callback);
ftpSrv.setTransferCallback(_transferCallback);
ftpSrv.begin("wioterminal","wioterminal");    //username, password for ftp.
}
void loop(void) {
ftpSrv.handleFTP();        //make sure in loop you call handleFTP()!!
}

Here the serial output:

Connecting to <YOUR-SSID>
WiFi connected
IP address:
192.168.1.176
>>>>>>>>>>>>>>> _callback 0 1470368 1927168
>>>>>>>>>>>>>>> _transferCallback 0 tappo.stl 0
>>>>>>>>>>>>>>> _transferCallback 1 tappo.stl 1024
>>>>>>>>>>>>>>> _transferCallback 1 tappo.stl 2048
[...]
>>>>>>>>>>>>>>> _transferCallback 1 tappo.stl 58368
>>>>>>>>>>>>>>> _transferCallback 1 tappo.stl 58550
>>>>>>>>>>>>>>> _transferCallback 4 tappo.stl 58550
>>>>>>>>>>>>>>> _callback 2 1470304 1927168
>>>>>>>>>>>>>>> _transferCallback 2 test.gif 46160
>>>>>>>>>>>>>>> _transferCallback 3 test.gif 2048
>>>>>>>>>>>>>>> _transferCallback 3 test.gif 4096
[...]
>>>>>>>>>>>>>>> _transferCallback 3 test.gif 45056
>>>>>>>>>>>>>>> _transferCallback 3 test.gif 46160
>>>>>>>>>>>>>>> _transferCallback 4 test.gif 46160

We are going to analize the output:

• line 5: identify the connection of the client;
• from 7 to 13: at line 7 start upload transfer from 8 to 12 transfer in course at line 13 finish transfer;
• line 15: free space changed;
• from 17 to 23: at line 17 start download transfer from 18 to 22 transfer in course at line 23 finish transfer.

Add graphical interface to monitor the FTP Server

Now if we want to add some information about the FTP server, we can use the device’s TFT display.

The code become more complex with the management of TFT, but It isn’t so difficult to read.

Display status

At first you will have this screen on the WioTerminal.

In this screen you can see that the wio terminal try to connect to my SSID reef-casa-sopra. Than when WiFi is connected you can see the strenght of the signal and free space.

Then with the IP, that you can see in the screen, you can try to connect with your FTP client. When connected the display change again.

Now you can transfer your files. Now I upload a small photo, and in the screen appear the transfer state Upload (and the stranferred size that change constantely).

When the transfer is successful, you can check the status changed to OK on the screen.

Sketch with complete server and display of the status

Here the complete sketch.

/*
* FtpServer Wio Terminal with SdFat library
* and with callbacks to the main actions of FTP server
* and a monitor on TFT
*
* AUTHOR:  Renzo Mischianti
*
* https://www.mischianti.org/2021/07/01/simple-ftp-server-library-now-with-support-for-wio-terminal-and-sd/*
*/
#include "SdFat.h"
#include <rpcWiFi.h>
#include <TFT_eSPI.h> // Hardware-specific library
#include <SPI.h>
#include <FtpServer.h>
TFT_eSPI tft = TFT_eSPI(); // Invoke custom library
#define DEG2RAD 0.0174532925
byte inc = 0;
unsigned int col = 0;
#define SD_CONFIG SdSpiConfig(SDCARD_SS_PIN, 2)
SdFs sd;
FtpServer ftpSrv;
const char *ssid = "reef-casa-sopra";
const char *password = "aabbccdd77";
#define MAIN_TOP 110
#define FREE_SPACE_PIE_X 80
#define FREE_SPACE_PIE_Y MAIN_TOP+40
#define FREE_SPACE_PIE_RADIUS 50
void freeSpacePieData(unsigned int freeSpace, unsigned int totalSpace) {
int pieFree = 360 - (freeSpace * 360 / totalSpace);
fillSegment(FREE_SPACE_PIE_X, FREE_SPACE_PIE_Y, 0, pieFree, FREE_SPACE_PIE_RADIUS, TFT_RED);
fillSegment(FREE_SPACE_PIE_X, FREE_SPACE_PIE_Y, pieFree, 360 - pieFree, FREE_SPACE_PIE_RADIUS, TFT_BLUE);
// Set "cursor" at top left corner of display (0,0) and select font 2
// (cursor will move to next line automatically during printing with 'tft.println'
//  or stay on the line is there is room for the text with tft.print)
tft.setCursor(FREE_SPACE_PIE_X + 80, MAIN_TOP, 2);
// Set the font colour to be white with a black background, set text size multiplier to 1
tft.setTextColor(TFT_WHITE, TFT_BLACK);  tft.setTextSize(1);
// We can now plot text on screen using the "print" class
Serial.print(freeSpace/1000);Serial.print("Mb/");Serial.print(String(totalSpace/1000));Serial.println("Mb");
tft.print(freeSpace/1000);tft.print("Mb/");tft.print(String(totalSpace/1000));tft.println("Mb");
}
void connectedDisconnected(bool connected) {
tft.fillCircle(FREE_SPACE_PIE_X + 80 + 10, MAIN_TOP+25+7, 10, (connected)?TFT_GREEN:TFT_RED);
tft.setCursor(FREE_SPACE_PIE_X + 80 + 25, MAIN_TOP+25, 2);
tft.println("              ");
tft.setCursor(FREE_SPACE_PIE_X + 80 + 25, MAIN_TOP+25, 2);
(connected)?tft.println("Connected!"):tft.println("Disconnected!");
}
void transfer(bool transfer, bool upload) {
tft.fillCircle(FREE_SPACE_PIE_X + 80 + 10, MAIN_TOP+25+25+7, 10, (transfer)?(upload)?TFT_GREEN:TFT_BLUE:TFT_RED);
tft.setCursor(FREE_SPACE_PIE_X + 80 + 25, MAIN_TOP+25+25, 2);
tft.println("              ");
tft.setCursor(FREE_SPACE_PIE_X + 80 + 25, MAIN_TOP+25+25, 2);
(transfer)?tft.println((upload)?"Upload!":"Download!"):tft.println("Idle!");
}
//index - starting at, n- how many chars
char* subString(const char *s, int index, int n){
char* b = (char*) malloc((strlen(s) + 1) * sizeof(char));
strcpy(b,s);
Serial.println("--------------------------------------");
Serial.println(s);
Serial.println(index);
Serial.println(n);
char *res = new char[n + 1];
Serial.println(res);
sprintf(res, "%.*s", n, b + index);
Serial.println(res);
free(b);
return res;
}
void fileTransfer(FtpTransferOperation ftpOperation, const char* filename, unsigned int transferredSize) {
int yoffset = 2;
tft.setCursor(20, MAIN_TOP+(FREE_SPACE_PIE_RADIUS*2)+yoffset, 2);
tft.println(F("                          "));
tft.setCursor(20, MAIN_TOP+(FREE_SPACE_PIE_RADIUS*2)+yoffset, 2);
int lenfile = strlen(filename);
Serial.println(lenfile);
if (lenfile>22) {
tft.print(subString(filename, 0, 16));tft.print(F("~"));
tft.print( subString(filename, (lenfile-4), 4) );
} else {
tft.print(filename);
}
tft.setCursor(20+160, MAIN_TOP+(FREE_SPACE_PIE_RADIUS*2)+yoffset, 2);
tft.print(F("                         "));
tft.setCursor(20+160, MAIN_TOP+(FREE_SPACE_PIE_RADIUS*2)+yoffset, 2);
tft.print(transferredSize);tft.print("Kb");
tft.setCursor(320-55, MAIN_TOP+(FREE_SPACE_PIE_RADIUS*2)+yoffset, 2);
switch (ftpOperation) {
case FTP_UPLOAD:
tft.setTextColor(TFT_GREEN, TFT_BLACK);
tft.print(F("Upload"));
tft.setTextColor(TFT_WHITE, TFT_BLACK);
break;
case FTP_DOWNLOAD:
tft.setTextColor(TFT_BLUE, TFT_BLACK);
tft.print(F("Down"));
tft.setTextColor(TFT_WHITE, TFT_BLACK);
break;
case FTP_TRANSFER_STOP:
tft.setTextColor(TFT_GREEN, TFT_BLACK);
tft.print(F("OK"));
tft.setTextColor(TFT_WHITE, TFT_BLACK);
break;
case FTP_TRANSFER_ERROR:
tft.setTextColor(TFT_RED, TFT_BLACK);
tft.print(F("Error"));
tft.setTextColor(TFT_WHITE, TFT_BLACK);
break;
default:
break;
}
}
void wifiStrenght (int8_t RSSI, bool connection = false) {
Serial.print("RSSI --> ");Serial.println(RSSI);
int marginX = 30;
int startX = 90;
int widthW = 320-(startX+marginX);
int startY = 60;
int heightY = 10;
tft.setCursor(marginX, startY - 5, 2);
tft.print(F("                                         "));
tft.setCursor(marginX, startY - 5, 2);
if (connection) {
tft.print(F("Connectint to: "));
tft.print(ssid);
}else{
tft.println("WiFi str: ");
// 120 : 120-RSSI = 300 : x
tft.drawRoundRect(startX, startY, widthW, heightY, 5, TFT_WHITE);
uint32_t colorRSSI = TFT_GREEN;
if (abs(RSSI)<55) {
colorRSSI = TFT_GREEN;
} else if (abs(RSSI)<75) {
colorRSSI = TFT_YELLOW;
} else if (abs(RSSI)<75) {
colorRSSI = TFT_RED;
}
tft.fillRoundRect(startX+1, startY+1, (120+RSSI)*widthW/120, heightY-2, 5, colorRSSI);
tft.setCursor(marginX, startY + 15, 2);
tft.print("IP: ");
tft.println(WiFi.localIP());
}
}
void _callback(FtpOperation ftpOperation, unsigned int freeSpace, unsigned int totalSpace){
Serial.print(">>>>>>>>>>>>>>> _callback " );
Serial.print(ftpOperation);
/* FTP_CONNECT,
* FTP_DISCONNECT,
* FTP_FREE_SPACE_CHANGE
*/
Serial.print(" ");
Serial.print(freeSpace);
Serial.print(" ");
Serial.println(totalSpace);
// freeSpace : totalSpace = x : 360
freeSpacePieData(freeSpace, totalSpace);
if (ftpOperation == FTP_CONNECT) connectedDisconnected(true);
if (ftpOperation == FTP_DISCONNECT) connectedDisconnected(false);
};
void _transferCallback(FtpTransferOperation ftpOperation, const char* name, unsigned int transferredSize){
Serial.print(">>>>>>>>>>>>>>> _transferCallback " );
Serial.print(ftpOperation);
/* FTP_UPLOAD_START = 0,
* FTP_UPLOAD = 1,
*
* FTP_DOWNLOAD_START = 2,
* FTP_DOWNLOAD = 3,
*
* FTP_TRANSFER_STOP = 4,
* FTP_DOWNLOAD_STOP = 4,
* FTP_UPLOAD_STOP = 4,
*
* FTP_TRANSFER_ERROR = 5,
* FTP_DOWNLOAD_ERROR = 5,
* FTP_UPLOAD_ERROR = 5
*/
Serial.print(" ");
Serial.print(name);
Serial.print(" ");
Serial.println(transferredSize);
(ftpOperation==FTP_UPLOAD || ftpOperation==FTP_DOWNLOAD)?transfer(true, ftpOperation==FTP_UPLOAD):transfer(false, false);
fileTransfer(ftpOperation, name, transferredSize);
};
void setup()
{
ftpSrv.setCallback(_callback);
ftpSrv.setTransferCallback(_transferCallback);
Serial.begin(115200);
delay(1000);
tft.init();
tft.begin();
tft.setRotation(3);
tft.fillScreen(TFT_BLACK);
tft.setCursor(0, 0);
tft.setTextColor(TFT_BLACK, TFT_WHITE);  tft.setTextSize(2);
tft.fillRoundRect(3, 3, 320-6, 40, 5, TFT_WHITE);
tft.drawCentreString("www.mischianti.org", 160, 14,1);
tft.setTextColor(TFT_WHITE, TFT_BLACK);
freeSpacePieData(0, 0);
connectedDisconnected(false);
transfer(false, false);
wifiStrenght(0, true);
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.print(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED)
{
Serial.print(".");
WiFi.begin(ssid, password);
Serial.print(".");
tft.print(F("."));
delay(500);
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
wifiStrenght(WiFi.RSSI());
delay(1000);
if (!sd.begin(SD_CONFIG)) {
sd.initErrorHalt(&Serial);
}
FsFile dir;
FsFile file;
// Open root directory
if (!dir.open("/")){
Serial.println("dir.open failed");
}
ftpSrv.begin("wioterminal","wioterminal");    //username, password for ftp.
}
void loop() {
ftpSrv.handleFTP();        //make sure in loop you call handleFTP()!!
}
// #########################################################################
// Draw circle segments
// #########################################################################
// x,y == coords of centre of circle
// start_angle = 0 - 359
// sub_angle   = 0 - 360 = subtended angle
// r = radius
// colour = 16 bit colour value
int fillSegment(int x, int y, int start_angle, int sub_angle, int r, unsigned int colour) {
// Calculate first pair of coordinates for segment start
float sx = cos((start_angle - 90) * DEG2RAD);
float sy = sin((start_angle - 90) * DEG2RAD);
uint16_t x1 = sx * r + x;
uint16_t y1 = sy * r + y;
// Draw colour blocks every inc degrees
for (int i = start_angle; i < start_angle + sub_angle; i++) {
// Calculate pair of coordinates for segment end
int x2 = cos((i + 1 - 90) * DEG2RAD) * r + x;
int y2 = sin((i + 1 - 90) * DEG2RAD) * r + y;
tft.fillTriangle(x1, y1, x2, y2, x, y, colour);
// Copy segment end to sgement start for next segment
x1 = x2;
y1 = y2;
}
}
// #########################################################################
// Return the 16 bit colour with brightness 0-100%
// #########################################################################
unsigned int brightness(unsigned int colour, int brightness) {
byte red   = colour >> 11;
byte green = (colour & 0x7E0) >> 5;
byte blue  = colour & 0x1F;
blue = (blue * brightness) / 100;
green = (green * brightness) / 100;
red = (red * brightness) / 100;
return (red << 11) + (green << 5) + blue;
}

You can find the example also in the library.

Configure client

This library support only passive mode and you must force only one connection at time.

I use FileZilla as client, you can download It here, It quite simple to use and configure.

Filezilla configuration for access esp8266, select plain FTP on Manage Site

First you must go on Manage site --> New site and now set this parameter:

Select FTP as protocol;Select Use plain FTP (insecure);Than on Trasfer settings select Maximun number of connection equal 1;

• Set you login and password (you choice that in sketch);
• Now connect to your device.

Filezilla configuration for access esp8266, select max num connections

If you want to transfer big file, you must extend timeout time.

Thanks

• SimpleFTPServer library: esp32 and esp8266 how to
• SimpleFTPServer library: WioTerminal how to