/AsyncWebServer_STM32

AsyncWebServer for STM32 using builtin LAN8742A Ethernet. This AsyncWebServer Library for STM32 is currently working on STM32 boards, such as Nucleo-144 F767ZI, etc., using builtin LAN8742A Ethernet

Primary LanguageCMIT LicenseMIT

AsyncWebServer_STM32

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Table of contents

Why do we need this AsyncWebServer_STM32 library

Features

This library is based on, modified from:

  1. Hristo Gochkov's ESPAsyncWebServer

to apply the better and faster asynchronous feature of the powerful ESPAsyncWebServer Library into STM32F/L/H/G/WB/MP1 boards using LAN8720 or built-in LAN8742A Ethernet.

Why Async is better

  • Using asynchronous network means that you can handle more than one connection at the same time
  • You are called once the request is ready and parsed
  • When you send the response, you are immediately ready to handle other connections while the server is taking care of sending the response in the background
  • Speed is OMG
  • Easy to use API, HTTP Basic and Digest MD5 Authentication (default), ChunkedResponse
  • Easily extensible to handle any type of content
  • Supports Continue 100
  • Async WebSocket plugin offering different locations without extra servers or ports
  • Async EventSource (Server-Sent Events) plugin to send events to the browser
  • URL Rewrite plugin for conditional and permanent url rewrites
  • ServeStatic plugin that supports cache, Last-Modified, default index and more
  • Simple template processing engine to handle templates

Currently supported Boards

  1. STM32F/L/H/G/WB/MP1 boards with built-in Ethernet LAN8742A such as :
  1. STM32F4/F7 boards using Ethernet LAN8720 such as :
  • Nucleo-144 (F429ZI, NUCLEO_F746NG, NUCLEO_F746ZG, NUCLEO_F756ZG)
  • Discovery (DISCO_F746NG)
  • STM32F4 boards (BLACK_F407VE, BLACK_F407VG, BLACK_F407ZE, BLACK_F407ZG, BLACK_F407VE_Mini, DIYMORE_F407VGT, FK407M1)

Prerequisites

  1. Arduino IDE 1.8.19+ for Arduino. GitHub release
  2. Arduino Core for STM32 v2.2.0+ for STM32 boards. GitHub release
  3. STM32Ethernet library v1.2.0+ for built-in LAN8742A Ethernet on (Nucleo-144, Discovery). GitHub release
  4. LwIP library v2.1.2+ for built-in LAN8742A Ethernet on (Nucleo-144, Discovery). GitHub release
  5. STM32AsyncTCP library v1.0.1+ for built-in Ethernet on (Nucleo-144, Discovery). To install manually for Arduino IDE.

Installation

Use Arduino Library Manager

The best and easiest way is to use Arduino Library Manager. Search for AsyncWebServer_STM32, then select / install the latest version. You can also use this link arduino-library-badge for more detailed instructions.

Manual Install

  1. Navigate to AsyncWebServer_STM32 page.
  2. Download the latest release AsyncWebServer_STM32-master.zip.
  3. Extract the zip file to AsyncWebServer_STM32-master directory
  4. Copy the whole AsyncWebServer_STM32-master folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO:

  1. Install VS Code
  2. Install PlatformIO
  3. Install AsyncWebServer_STM32 library by using Library Manager. Search for AsyncWebServer_STM32 in Platform.io Author's Libraries
  4. Use included platformio.ini file from examples to ensure that all dependent libraries will installed automatically. Please visit documentation for the other options and examples at Project Configuration File

Packages' Patches

1. For STM32 boards to use LAN8720

To use LAN8720 on some STM32 boards

  • Nucleo-144 (F429ZI, NUCLEO_F746NG, NUCLEO_F746ZG, NUCLEO_F756ZG)
  • Discovery (DISCO_F746NG)
  • STM32F4 boards (BLACK_F407VE, BLACK_F407VG, BLACK_F407ZE, BLACK_F407ZG, BLACK_F407VE_Mini, DIYMORE_F407VGT, FK407M1)

you have to copy the files stm32f4xx_hal_conf_default.h and stm32f7xx_hal_conf_default.h into STM32 stm32 directory (~/.arduino15/packages/STM32/hardware/stm32/2.2.0/system) to overwrite the old files.

Supposing the STM32 stm32 core version is 2.2.0. These files must be copied into the directory:

  • ~/.arduino15/packages/STM32/hardware/stm32/2.2.0/system/STM32F4xx/stm32f4xx_hal_conf_default.h for STM32F4.
  • ~/.arduino15/packages/STM32/hardware/stm32/2.2.0/system/STM32F7xx/stm32f7xx_hal_conf_default.h for Nucleo-144 STM32F7.

Whenever a new version is installed, remember to copy this file into the new version directory. For example, new version is x.yy.zz, theses files must be copied into the corresponding directory:

  • ~/.arduino15/packages/STM32/hardware/stm32/x.yy.zz/system/STM32F4xx/stm32f4xx_hal_conf_default.h
  • `~/.arduino15/packages/STM32/hardware/stm32/x.yy.zz/system/STM32F7xx/stm32f7xx_hal_conf_default.h

2. For STM32 boards to use Serial1

To use Serial1 on some STM32 boards without Serial1 definition (Nucleo-144 NUCLEO_F767ZI, Nucleo-64 NUCLEO_L053R8, etc.) boards, you have to copy the files STM32 variant.h into STM32 stm32 directory (~/.arduino15/packages/STM32/hardware/stm32/2.2.0). You have to modify the files corresponding to your boards, this is just an illustration how to do.

Supposing the STM32 stm32 core version is 2.2.0. These files must be copied into the directory:

  • ~/.arduino15/packages/STM32/hardware/stm32/2.2.0/variants/STM32F7xx/F765Z(G-I)T_F767Z(G-I)T_F777ZIT/NUCLEO_F767ZI/variant.h for Nucleo-144 NUCLEO_F767ZI.
  • ~/.arduino15/packages/STM32/hardware/stm32/2.2.0/variants/STM32L0xx/L052R(6-8)T_L053R(6-8)T_L063R8T/NUCLEO_L053R8/variant.h for Nucleo-64 NUCLEO_L053R8.

Whenever a new version is installed, remember to copy this file into the new version directory. For example, new version is x.yy.zz, theses files must be copied into the corresponding directory:

  • ~/.arduino15/packages/STM32/hardware/stm32/x.yy.zz/variants/STM32F7xx/F765Z(G-I)T_F767Z(G-I)T_F777ZIT/NUCLEO_F767ZI/variant.h
  • ~/.arduino15/packages/STM32/hardware/stm32/x.yy.zz/variants/STM32L0xx/L052R(6-8)T_L053R(6-8)T_L063R8T/NUCLEO_L053R8/variant.h

Important things to remember

  • This is fully asynchronous server and as such does not run on the loop thread.
  • You can not use yield() or delay() or any function that uses them inside the callbacks
  • The server is smart enough to know when to close the connection and free resources
  • You can not send more than one response to a single request

Principles of operation

The Async Web server

  • Listens for connections
  • Wraps the new clients into Request
  • Keeps track of clients and cleans memory
  • Manages Rewrites and apply them on the request url
  • Manages Handlers and attaches them to Requests

Request Life Cycle

  • TCP connection is received by the server
  • The connection is wrapped inside Request object
  • When the request head is received (type, url, get params, http version and host), the server goes through all Rewrites (in the order they were added) to rewrite the url and inject query parameters, next, it goes through all attached Handlers(in the order they were added) trying to find one that canHandle the given request. If none are found, the default(catch-all) handler is attached.
  • The rest of the request is received, calling the handleUpload or handleBody methods of the Handler if they are needed (POST+File/Body)
  • When the whole request is parsed, the result is given to the handleRequest method of the Handler and is ready to be responded to
  • In the handleRequest method, to the Request is attached a Response object (see below) that will serve the response data back to the client
  • When the Response is sent, the client is closed and freed from the memory

Rewrites and how do they work

  • The Rewrites are used to rewrite the request url and/or inject get parameters for a specific request url path.
  • All Rewrites are evaluated on the request in the order they have been added to the server.
  • The Rewrite will change the request url only if the request url (excluding get parameters) is fully match the rewrite url, and when the optional Filter callback return true.
  • Setting a Filter to the Rewrite enables to control when to apply the rewrite, decision can be based on request url, http version, request host/port/target host, get parameters or the request client's localIP or remoteIP.
  • The Rewrite can specify a target url with optional get parameters, e.g. /to-url?with=params

Handlers and how do they work

  • The Handlers are used for executing specific actions to particular requests
  • One Handler instance can be attached to any request and lives together with the server
  • Setting a Filter to the Handler enables to control when to apply the handler, decision can be based on request url, http version, request host/port/target host, get parameters or the request client's localIP or remoteIP.
  • The canHandle method is used for handler specific control on whether the requests can be handled and for declaring any interesting headers that the Request should parse. Decision can be based on request method, request url, http version, request host/port/target host and get parameters
  • Once a Handler is attached to given Request (canHandle returned true) that Handler takes care to receive any file/data upload and attach a Response once the Request has been fully parsed
  • Handlers are evaluated in the order they are attached to the server. The canHandle is called only if the Filter that was set to the Handler return true.
  • The first Handler that can handle the request is selected, not further Filter and canHandle are called.

Responses and how do they work

  • The Response objects are used to send the response data back to the client
  • The Response object lives with the Request and is freed on end or disconnect
  • Different techniques are used depending on the response type to send the data in packets returning back almost immediately and sending the next packet when this one is received. Any time in between is spent to run the user loop and handle other network packets
  • Responding asynchronously is probably the most difficult thing for most to understand
  • Many different options exist for the user to make responding a background task

Template processing

  • AsyncWebserver_STM32 contains simple template processing engine.
  • Template processing can be added to most response types.
  • Currently it supports only replacing template placeholders with actual values. No conditional processing, cycles, etc.
  • Placeholders are delimited with % symbols. Like this: %TEMPLATE_PLACEHOLDER%.
  • It works by extracting placeholder name from response text and passing it to user provided function which should return actual value to be used instead of placeholder.
  • Since it's user provided function, it is possible for library users to implement conditional processing and cycles themselves.
  • Since it's impossible to know the actual response size after template processing step in advance (and, therefore, to include it in response headers), the response becomes chunked.

Request Variables

Common Variables

request->version();       // uint8_t: 0 = HTTP/1.0, 1 = HTTP/1.1
request->method();        // enum:    HTTP_GET, HTTP_POST, HTTP_DELETE, HTTP_PUT, HTTP_PATCH, HTTP_HEAD, HTTP_OPTIONS
request->url();           // String:  URL of the request (not including host, port or GET parameters)
request->host();          // String:  The requested host (can be used for virtual hosting)
request->contentType();   // String:  ContentType of the request (not avaiable in Handler::canHandle)
request->contentLength(); // size_t:  ContentLength of the request (not avaiable in Handler::canHandle)
request->multipart();     // bool:    True if the request has content type "multipart"

Headers

//List all collected headers
int headers = request->headers();
int i;

for(i=0;i<headers;i++)
{
  AsyncWebHeader* h = request->getHeader(i);
  Serial.printf("HEADER[%s]: %s\n", h->name().c_str(), h->value().c_str());
}

//get specific header by name
if(request->hasHeader("MyHeader"))
{
  AsyncWebHeader* h = request->getHeader("MyHeader");
  Serial.printf("MyHeader: %s\n", h->value().c_str());
}

//List all collected headers (Compatibility)
int headers = request->headers();
int i;

for(i=0;i<headers;i++)
{
  Serial.printf("HEADER[%s]: %s\n", request->headerName(i).c_str(), request->header(i).c_str());
}

//get specific header by name (Compatibility)
if(request->hasHeader("MyHeader"))
{
  Serial.printf("MyHeader: %s\n", request->header("MyHeader").c_str());
}

GET, POST and FILE parameters

//List all parameters
int params = request->params();

for(int i=0;i<params;i++)
{
  AsyncWebParameter* p = request->getParam(i);
  
  if(p->isFile())
  { 
    //p->isPost() is also true
    Serial.printf("FILE[%s]: %s, size: %u\n", p->name().c_str(), p->value().c_str(), p->size());
  } 
  else if(p->isPost())
  {
    Serial.printf("POST[%s]: %s\n", p->name().c_str(), p->value().c_str());
  } 
  else 
  {
    Serial.printf("GET[%s]: %s\n", p->name().c_str(), p->value().c_str());
  }
}

//Check if GET parameter exists
if(request->hasParam("download"))
  AsyncWebParameter* p = request->getParam("download");

//Check if POST (but not File) parameter exists
if(request->hasParam("download", true))
  AsyncWebParameter* p = request->getParam("download", true);

//Check if FILE was uploaded
if(request->hasParam("download", true, true))
  AsyncWebParameter* p = request->getParam("download", true, true);

//List all parameters (Compatibility)
int args = request->args();

for(int i=0;i<args;i++)
{
  Serial.printf("ARG[%s]: %s\n", request->argName(i).c_str(), request->arg(i).c_str());
}

//Check if parameter exists (Compatibility)
if(request->hasArg("download"))
  String arg = request->arg("download");

JSON body handling with ArduinoJson

Endpoints which consume JSON can use a special handler to get ready to use JSON data in the request callback:

#include "AsyncJson.h"
#include "ArduinoJson.h"

AsyncCallbackJsonWebHandler* handler = new AsyncCallbackJsonWebHandler("/rest/endpoint", [](AsyncWebServerRequest *request, JsonVariant &json) 
{
  JsonObject& jsonObj = json.as<JsonObject>();
  // ...
});

server.addHandler(handler);

Responses

Redirect to another URL

//to local url
request->redirect("/login");

//to external url
request->redirect("http://esp8266.com");

Basic response with HTTP Code

request->send(404); //Sends 404 File Not Found

Basic response with HTTP Code and extra headers

AsyncWebServerResponse *response = request->beginResponse(404); //Sends 404 File Not Found
response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Basic response with string content

request->send(200, "text/plain", "Hello World!");

Basic response with string content and extra headers

AsyncWebServerResponse *response = request->beginResponse(200, "text/plain", "Hello World!");
response->addHeader("Server","AsyncWebServer");
request->send(response);

Respond with content coming from a Stream

//read 12 bytes from Serial and send them as Content Type text/plain
request->send(Serial, "text/plain", 12);

Respond with content coming from a Stream and extra headers

//read 12 bytes from Serial and send them as Content Type text/plain
AsyncWebServerResponse *response = request->beginResponse(Serial, "text/plain", 12);
response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Respond with content coming from a Stream containing templates

String processor(const String& var)
{
  if(var == "HELLO_FROM_TEMPLATE")
    return F("Hello world!");
    
  return String();
}

// ...

//read 12 bytes from Serial and send them as Content Type text/plain
request->send(Serial, "text/plain", 12, processor);

Respond with content coming from a Stream containing templates and extra headers

String processor(const String& var)
{
  if(var == "HELLO_FROM_TEMPLATE")
    return F("Hello world!");
  return String();
}

// ...

//read 12 bytes from Serial and send them as Content Type text/plain
AsyncWebServerResponse *response = request->beginResponse(Serial, "text/plain", 12, processor);
response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Respond with content using a callback

//send 128 bytes as plain text
request->send("text/plain", 128, [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will not be asked for more bytes once the content length has been reached.
  //Keep in mind that you can not delay or yield waiting for more data!
  //Send what you currently have and you will be asked for more again
  return mySource.read(buffer, maxLen);
});

Respond with content using a callback and extra headers

//send 128 bytes as plain text
AsyncWebServerResponse *response = request->beginResponse("text/plain", 128, [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will not be asked for more bytes once the content length has been reached.
  //Keep in mind that you can not delay or yield waiting for more data!
  //Send what you currently have and you will be asked for more again
  return mySource.read(buffer, maxLen);
});

response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Respond with content using a callback containing templates

String processor(const String& var)
{
  if(var == "HELLO_FROM_TEMPLATE")
    return F("Hello world!");
    
  return String();
}

// ...

//send 128 bytes as plain text
request->send("text/plain", 128, [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will not be asked for more bytes once the content length has been reached.
  //Keep in mind that you can not delay or yield waiting for more data!
  //Send what you currently have and you will be asked for more again
  return mySource.read(buffer, maxLen);
}, processor);

Respond with content using a callback containing templates and extra headers

String processor(const String& var)
{
  if(var == "HELLO_FROM_TEMPLATE")
    return F("Hello world!");
  return String();
}

// ...

//send 128 bytes as plain text
AsyncWebServerResponse *response = request->beginResponse("text/plain", 128, [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will not be asked for more bytes once the content length has been reached.
  //Keep in mind that you can not delay or yield waiting for more data!
  //Send what you currently have and you will be asked for more again
  return mySource.read(buffer, maxLen);
}, processor);

response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Chunked Response

Used when content length is unknown. Works best if the client supports HTTP/1.1

AsyncWebServerResponse *response = request->beginChunkedResponse("text/plain", [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will be asked for more data until 0 is returned
  //Keep in mind that you can not delay or yield waiting for more data!
  return mySource.read(buffer, maxLen);
});

response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Chunked Response containing templates

Used when content length is unknown. Works best if the client supports HTTP/1.1

String processor(const String& var)
{
  if(var == "HELLO_FROM_TEMPLATE")
    return F("Hello world!");
    
  return String();
}

// ...

AsyncWebServerResponse *response = request->beginChunkedResponse("text/plain", [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //index equals the amount of bytes that have been already sent
  //You will be asked for more data until 0 is returned
  //Keep in mind that you can not delay or yield waiting for more data!
  return mySource.read(buffer, maxLen);
}, processor);

response->addHeader("Server","AsyncWebServer_STM32");
request->send(response);

Print to response

AsyncResponseStream *response = request->beginResponseStream("text/html");
response->addHeader("Server","AsyncWebServer_STM32");
response->printf("<!DOCTYPE html><html><head><title>Webpage at %s</title></head><body>", request->url().c_str());

response->print("<h2>Hello ");
response->print(request->client()->remoteIP());
response->print("</h2>");

response->print("<h3>General</h3>");
response->print("<ul>");
response->printf("<li>Version: HTTP/1.%u</li>", request->version());
response->printf("<li>Method: %s</li>", request->methodToString());
response->printf("<li>URL: %s</li>", request->url().c_str());
response->printf("<li>Host: %s</li>", request->host().c_str());
response->printf("<li>ContentType: %s</li>", request->contentType().c_str());
response->printf("<li>ContentLength: %u</li>", request->contentLength());
response->printf("<li>Multipart: %s</li>", request->multipart()?"true":"false");
response->print("</ul>");

response->print("<h3>Headers</h3>");
response->print("<ul>");
int headers = request->headers();

for(int i=0;i<headers;i++)
{
  AsyncWebHeader* h = request->getHeader(i);
  response->printf("<li>%s: %s</li>", h->name().c_str(), h->value().c_str());
}

response->print("</ul>");

response->print("<h3>Parameters</h3>");
response->print("<ul>");

int params = request->params();

for(int i=0;i<params;i++)
{
  AsyncWebParameter* p = request->getParam(i);
  
  if(p->isFile())
  {
    response->printf("<li>FILE[%s]: %s, size: %u</li>", p->name().c_str(), p->value().c_str(), p->size());
  } 
  else if(p->isPost())
  {
    response->printf("<li>POST[%s]: %s</li>", p->name().c_str(), p->value().c_str());
  } 
  else 
  {
    response->printf("<li>GET[%s]: %s</li>", p->name().c_str(), p->value().c_str());
  }
}

response->print("</ul>");

response->print("</body></html>");
//send the response last
request->send(response);

ArduinoJson Basic Response

This way of sending Json is great for when the result is below 4KB

#include "AsyncJson.h"
#include "ArduinoJson.h"


AsyncResponseStream *response = request->beginResponseStream("application/json");
DynamicJsonBuffer jsonBuffer;
JsonObject &root = jsonBuffer.createObject();
root["heap"] = ESP.getFreeHeap();
root["ssid"] = WiFi.SSID();
root.printTo(*response);

request->send(response);

ArduinoJson Advanced Response

This response can handle really large Json objects (tested to 40KB)

There isn't any noticeable speed decrease for small results with the method above

Since ArduinoJson does not allow reading parts of the string, the whole Json has to be passed every time a chunks needs to be sent, which shows speed decrease proportional to the resulting json packets

#include "AsyncJson.h"
#include "ArduinoJson.h"

AsyncJsonResponse * response = new AsyncJsonResponse();
response->addHeader("Server","AsyncWebServer");
JsonObject& root = response->getRoot();
root["IP"] = Ethernet.localIP();
response->setLength();

request->send(response);

Param Rewrite With Matching

It is possible to rewrite the request url with parameter matchg. Here is an example with one parameter: Rewrite for example "/radio/{frequence}" -> "/radio?f={frequence}"

class OneParamRewrite : public AsyncWebRewrite
{
  protected:
    String _urlPrefix;
    int _paramIndex;
    String _paramsBackup;

  public:
  OneParamRewrite(const char* from, const char* to)
    : AsyncWebRewrite(from, to) 
    {

      _paramIndex = _from.indexOf('{');

      if( _paramIndex >=0 && _from.endsWith("}")) 
      {
        _urlPrefix = _from.substring(0, _paramIndex);
        int index = _params.indexOf('{');
        
        if(index >= 0) 
        {
          _params = _params.substring(0, index);
        }
      } 
      else 
      {
        _urlPrefix = _from;
      }
      
      _paramsBackup = _params;
  }

  bool match(AsyncWebServerRequest *request) override 
  {
    if(request->url().startsWith(_urlPrefix)) 
    {
      if(_paramIndex >= 0) 
      {
        _params = _paramsBackup + request->url().substring(_paramIndex);
      } 
      else 
      {
        _params = _paramsBackup;
      }
      
      return true;

    } 
    else 
    {
      return false;
    }
  }
};

Usage:

  server.addRewrite( new OneParamRewrite("/radio/{frequence}", "/radio?f={frequence}") );

Using filters

Filters can be set to Rewrite or Handler in order to control when to apply the rewrite and consider the handler. A filter is a callback function that evaluates the request and return a boolean true to include the item or false to exclude it.

Bad Responses

Some responses are implemented, but you should not use them, because they do not conform to HTTP. The following example will lead to unclean close of the connection and more time wasted than providing the length of the content

Respond with content using a callback without content length to HTTP/1.0 clients

//This is used as fallback for chunked responses to HTTP/1.0 Clients
request->send("text/plain", 0, [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t 
{
  //Write up to "maxLen" bytes into "buffer" and return the amount written.
  //You will be asked for more data until 0 is returned
  //Keep in mind that you can not delay or yield waiting for more data!
  return mySource.read(buffer, maxLen);
});

Async WebSocket Plugin

The server includes a web socket plugin which lets you define different WebSocket locations to connect to without starting another listening service or using different port

Async WebSocket Event

void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventType type, void * arg, uint8_t *data, size_t len)
{
  if(type == WS_EVT_CONNECT)
  {
    //client connected
    Serial.printf("ws[%s][%u] connect\n", server->url(), client->id());
    client->printf("Hello Client %u :)", client->id());
    client->ping();
  } 
  else if(type == WS_EVT_DISCONNECT)
  {
    //client disconnected
    Serial.printf("ws[%s][%u] disconnect: %u\n", server->url(), client->id());
  } 
  else if(type == WS_EVT_ERROR)
  {
    //error was received from the other end
    Serial.printf("ws[%s][%u] error(%u): %s\n", server->url(), client->id(), *((uint16_t*)arg), (char*)data);
  } 
  else if(type == WS_EVT_PONG)
  {
    //pong message was received (in response to a ping request maybe)
    Serial.printf("ws[%s][%u] pong[%u]: %s\n", server->url(), client->id(), len, (len)?(char*)data:"");
  } 
  else if(type == WS_EVT_DATA)
  {
    //data packet
    AwsFrameInfo * info = (AwsFrameInfo*)arg;
    
    if(info->final && info->index == 0 && info->len == len)
    {
      //the whole message is in a single frame and we got all of it's data
      Serial.printf("ws[%s][%u] %s-message[%llu]: ", server->url(), client->id(), (info->opcode == WS_TEXT)?"text":"binary", info->len);
      
      if(info->opcode == WS_TEXT)
      {
        data[len] = 0;
        Serial.printf("%s\n", (char*)data);
      } 
      else 
      {
        for(size_t i=0; i < info->len; i++)
        {
          Serial.printf("%02x ", data[i]);
        }
        
        Serial.printf("\n");
      }
      
      if(info->opcode == WS_TEXT)
        client->text("I got your text message");
      else
        client->binary("I got your binary message");
    } 
    else 
    {
      //message is comprised of multiple frames or the frame is split into multiple packets
      if(info->index == 0)
      {
        if(info->num == 0)
          Serial.printf("ws[%s][%u] %s-message start\n", server->url(), client->id(), (info->message_opcode == WS_TEXT)?"text":"binary");
          
        Serial.printf("ws[%s][%u] frame[%u] start[%llu]\n", server->url(), client->id(), info->num, info->len);
      }

      Serial.printf("ws[%s][%u] frame[%u] %s[%llu - %llu]: ", server->url(), client->id(), info->num, (info->message_opcode == WS_TEXT)?"text":"binary", info->index, info->index + len);
      
      if(info->message_opcode == WS_TEXT)
      {
        data[len] = 0;
        Serial.printf("%s\n", (char*)data);
      } 
      else 
      {
        for(size_t i=0; i < len; i++){
          Serial.printf("%02x ", data[i]);
        }
        Serial.printf("\n");
      }

      if((info->index + len) == info->len)
      {
        Serial.printf("ws[%s][%u] frame[%u] end[%llu]\n", server->url(), client->id(), info->num, info->len);
        
        if(info->final)
        {
          Serial.printf("ws[%s][%u] %s-message end\n", server->url(), client->id(), (info->message_opcode == WS_TEXT)?"text":"binary");
          
          if(info->message_opcode == WS_TEXT)
            client->text("I got your text message");
          else
            client->binary("I got your binary message");
        }
      }
    }
  }
}

Methods for sending data to a socket client

//Server methods
AsyncWebSocket ws("/ws");
//printf to a client
ws.printf((uint32_t)client_id, arguments...);
//printf to all clients
ws.printfAll(arguments...);
//send text to a client
ws.text((uint32_t)client_id, (char*)text);
ws.text((uint32_t)client_id, (uint8_t*)text, (size_t)len);
//send text to all clients
ws.textAll((char*)text);
ws.textAll((uint8_t*)text, (size_t)len);
//send binary to a client
ws.binary((uint32_t)client_id, (char*)binary);
ws.binary((uint32_t)client_id, (uint8_t*)binary, (size_t)len);
ws.binary((uint32_t)client_id, flash_binary, 4);
//send binary to all clients
ws.binaryAll((char*)binary);
ws.binaryAll((uint8_t*)binary, (size_t)len);
//HTTP Authenticate before switch to Websocket protocol
ws.setAuthentication("user", "pass");

//client methods
AsyncWebSocketClient * client;
//printf
client->printf(arguments...);
//send text
client->text((char*)text);
client->text((uint8_t*)text, (size_t)len);
//send binary
client->binary((char*)binary);
client->binary((uint8_t*)binary, (size_t)len);

Direct access to web socket message buffer

When sending a web socket message using the above methods a buffer is created. Under certain circumstances you might want to manipulate or populate this buffer directly from your application, for example to prevent unnecessary duplications of the data. This example below shows how to create a buffer and print data to it from an ArduinoJson object then send it.

void sendDataWs(AsyncWebSocketClient * client)
{
    DynamicJsonBuffer jsonBuffer;
    JsonObject& root = jsonBuffer.createObject();
    root["a"] = "abc";
    root["b"] = "abcd";
    root["c"] = "abcde";
    root["d"] = "abcdef";
    root["e"] = "abcdefg";
    size_t len = root.measureLength();
    AsyncWebSocketMessageBuffer * buffer = ws.makeBuffer(len); //  creates a buffer (len + 1) for you.
    
    if (buffer) 
    {
        root.printTo((char *)buffer->get(), len + 1);
        
        if (client) 
        {
            client->text(buffer);
        } 
        else 
        {
            ws.textAll(buffer);
        }
    }
}

Limiting the number of web socket clients

Browsers sometimes do not correctly close the websocket connection, even when the close() function is called in javascript. This will eventually exhaust the web server's resources and will cause the server to crash. Periodically calling the cleanClients() function from the main loop() function limits the number of clients by closing the oldest client when the maximum number of clients has been exceeded. This can called be every cycle, however, if you wish to use less power, then calling as infrequently as once per second is sufficient.

void loop(){
  ws.cleanupClients();
}

Async Event Source Plugin

The server includes EventSource (Server-Sent Events) plugin which can be used to send short text events to the browser. Difference between EventSource and WebSockets is that EventSource is single direction, text-only protocol.

Setup Event Source on the server

AsyncWebServer server(80);
AsyncEventSource events("/events");

void setup()
{
  // setup ......
  events.onConnect([](AsyncEventSourceClient *client)
  {
    if(client->lastId())
    {
      Serial.printf("Client reconnected! Last message ID that it got is: %u\n", client->lastId());
    }
    
    //send event with message "hello!", id current millis
    // and set reconnect delay to 1 second
    client->send("hello!",NULL,millis(),1000);
  });
  
  //HTTP Basic authentication
  events.setAuthentication("user", "pass");
  server.addHandler(&events);
  // setup ......
}

void loop()
{
  if(eventTriggered){ // your logic here
    //send event "myevent"
    events.send("my event content","myevent",millis());
  }
}

Setup Event Source in the browser

if (!!window.EventSource) 
{
  var source = new EventSource('/events');

  source.addEventListener('open', function(e) 
  {
    console.log("Events Connected");
  }, false);

  source.addEventListener('error', function(e) 
  {
    if (e.target.readyState != EventSource.OPEN) 
    {
      console.log("Events Disconnected");
    }
  }, false);

  source.addEventListener('message', function(e) 
  {
    console.log("message", e.data);
  }, false);

  source.addEventListener('myevent', function(e) 
  {
    console.log("myevent", e.data);
  }, false);
}

Remove handlers and rewrites

Server goes through handlers in same order as they were added. You can't simple add handler with same path to override them. To remove handler:

// save callback for particular URL path
auto handler = server.on("/some/path", [](AsyncWebServerRequest *request){
  //do something useful
});

// when you don't need handler anymore remove it
server.removeHandler(&handler);

// same with rewrites
server.removeRewrite(&someRewrite);

server.onNotFound([](AsyncWebServerRequest *request){
  request->send(404);
});

// remove server.onNotFound handler
server.onNotFound(NULL);

// remove all rewrites, handlers and onNotFound/onFileUpload/onRequestBody callbacks
server.reset();

Setting up the server

#include <LwIP.h>
#include <STM32Ethernet.h>
#include <AsyncWebServer_STM32.h>

// Enter a MAC address and IP address for your controller below.
#define NUMBER_OF_MAC      20

byte mac[][NUMBER_OF_MAC] =
{
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x01 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x02 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x03 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x04 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x05 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x06 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x07 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x08 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x09 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0A },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0B },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0C },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0D },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0E },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0F },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x10 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x11 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x12 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x13 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x14 },
};
// Select the IP address according to your local network
IPAddress ip(192, 168, 2, 232);

AsyncWebServer    server(80);

const int led = 13;

void handleRoot(AsyncWebServerRequest *request)
{
  digitalWrite(led, 1);
  request->send(200, "text/plain", String("Hello from AsyncWebServer_STM32 on ") + BOARD_NAME );
  digitalWrite(led, 0);
}

void handleNotFound(AsyncWebServerRequest *request)
{
  digitalWrite(led, 1);
  String message = "File Not Found\n\n";

  message += "URI: ";
  //message += server.uri();
  message += request->url();
  message += "\nMethod: ";
  message += (request->method() == HTTP_GET) ? "GET" : "POST";
  message += "\nArguments: ";
  message += request->args();
  message += "\n";

  for (uint8_t i = 0; i < request->args(); i++)
  {
    message += " " + request->argName(i) + ": " + request->arg(i) + "\n";
  }

  request->send(404, "text/plain", message);
  digitalWrite(led, 0);
}

void setup(void)
{
  pinMode(led, OUTPUT);
  digitalWrite(led, 0);

  Serial.begin(115200);
  Serial.println("\nStart Async_HelloServer on " + String(BOARD_NAME));

  // start the ethernet connection and the server
  // Use random mac
  uint16_t index = millis() % NUMBER_OF_MAC;

  // Use Static IP
  //Ethernet.begin(mac[index], ip);
  // Use DHCP dynamic IP and random mac
  Ethernet.begin(mac[index]);

  server.on("/", HTTP_GET, [](AsyncWebServerRequest * request)
  {
    handleRoot(request);
  });

  server.on("/inline", [](AsyncWebServerRequest * request)
  {
    request->send(200, "text/plain", "This works as well");
  });

  server.onNotFound(handleNotFound);

  server.begin();

  Serial.print(F("HTTP EthernetWebServer is @ IP : "));
  Serial.println(Ethernet.localIP());
}

void loop(void)
{
}

Setup global and class functions as request handlers

#include <Arduino.h>

#include <LwIP.h>
#include <STM32Ethernet.h>
#include <AsyncWebServer_STM32.h>

#include <functional>

...

void handleRequest(AsyncWebServerRequest *request){}

class WebClass 
{
public :
  AsyncWebServer classWebServer = AsyncWebServer(81);

  WebClass(){};

  void classRequest (AsyncWebServerRequest *request){}

  void begin()
  {
    // attach global request handler
    classWebServer.on("/example", HTTP_ANY, handleRequest);

    // attach class request handler
    classWebServer.on("/example", HTTP_ANY, std::bind(&WebClass::classRequest, this, std::placeholders::_1));
  }
};

AsyncWebServer globalWebServer(80);
WebClass webClassInstance;

void setup() 
{
  // attach global request handler
  globalWebServer.on("/example", HTTP_ANY, handleRequest);

  // attach class request handler
  globalWebServer.on("/example", HTTP_ANY, std::bind(&WebClass::classRequest, webClassInstance, std::placeholders::_1));
}

void loop() 
{

}

Methods for controlling websocket connections

  // Disable client connections if it was activated
  if ( ws.enabled() )
    ws.enable(false);

  // enable client connections if it was disabled
  if ( !ws.enabled() )
    ws.enable(true);

Adding Default Headers

In some cases, such as when working with CORS, or with some sort of custom authentication system, you might need to define a header that should get added to all responses (including static, websocket and EventSource). The DefaultHeaders singleton allows you to do this.

Example:

DefaultHeaders::Instance().addHeader("Access-Control-Allow-Origin", "*");
webServer.begin();

NOTE: You will still need to respond to the OPTIONS method for CORS pre-flight in most cases. (unless you are only using GET)

This is one option:

webServer.onNotFound([](AsyncWebServerRequest *request) 
{
  if (request->method() == HTTP_OPTIONS) {
    request->send(200);
  } else {
    request->send(404);
  }
});

Path variable

With path variable you can create a custom regex rule for a specific parameter in a route. For example we want a sensorId parameter in a route rule to match only a integer.

  server.on("^\\/sensor\\/([0-9]+)$", HTTP_GET, [] (AsyncWebServerRequest *request) 
  {
      String sensorId = request->pathArg(0);
  });

NOTE: All regex patterns starts with ^ and ends with $

To enable the Path variable support, you have to define the buildflag -DASYNCWEBSERVER_REGEX.

For Arduino IDE create/update platform.local.txt:

Windows: C:\Users(username)\AppData\Local\Arduino15\packages\{espxxxx}\hardware\espxxxx\{version}\platform.local.txt

Linux: ~/.arduino15/packages/{espxxxx}/hardware/{espxxxx}/{version}/platform.local.txt

Add/Update the following line:

  compiler.cpp.extra_flags=-DDASYNCWEBSERVER_REGEX

For platformio modify platformio.ini:

[env:myboard]
build_flags = 
  -DASYNCWEBSERVER_REGEX

NOTE: By enabling ASYNCWEBSERVER_REGEX, <regex> will be included. This will add an 100k to your binary.

HOWTO use STM32F4 with LAN8720

1. Wiring

This is the Wiring for STM32F4 (BLACK_F407VE, etc.) using LAN8720

LAN8720 PHY <---> STM32F4
TX1 <---> PB_13
TX_EN <---> PB_11
TX0 <---> PB_12
RX0 <---> PC_4
RX1 <---> PC_5
nINT/RETCLK <---> PA_1
CRS <---> PA_7
MDIO <---> PA_2
MDC <---> PC_1
GND <---> GND
VCC <---> +3.3V

2. HOWTO program using STLink V-2 or V-3

Connect as follows. To program, use STM32CubeProgrammer or Arduino IDE with

  • U(S)ART Support: "Enabled (generic Serial)"
  • Upload Method : "STM32CubeProgrammer (SWD)"
STLink <---> STM32F4
SWCLK <---> SWCLK
SWDIO <---> SWDIO
RST <---> NRST
GND <---> GND
5v <---> 5V

3. HOWTO use Serial Port for Debugging

Connect FDTI (USB to Serial) as follows:

FDTI <---> STM32F4
RX <---> TX=PA_9
TX <---> RX=PA_10
GND <---> GND

Examples

1. For LAN8742A

  1. Async_AdvancedWebServer
  2. AsyncFSBrowser_STM32
  3. Async_HelloServer
  4. Async_HelloServer2
  5. Async_HttpBasicAuth
  6. Async_PostServer
  7. AsyncMultiWebServer_STM32
  8. Async_RegexPatterns_STM32
  9. Async_SimpleWebServer_STM32
  10. MQTTClient_Auth
  11. MQTTClient_Basic
  12. MQTT_ThingStream
  13. WebClient
  14. WebClientRepeating

2. For LAN8720

  1. Async_AdvancedWebServer_LAN8720
  2. AsyncFSBrowser_STM32_LAN8720
  3. Async_HelloServer_LAN8720
  4. Async_HelloServer2_LAN8720
  5. Async_HttpBasicAuth_LAN8720
  6. AsyncMultiWebServer_STM32_LAN8720
  7. Async_PostServer_LAN8720
  8. Async_RegexPatterns_STM32_LAN8720
  9. Async_SimpleWebServer_STM32_LAN8720
  10. MQTTClient_Auth_LAN8720
  11. MQTTClient_Basic_LAN8720
  12. MQTT_ThingStream_LAN8720
  13. WebClient_LAN8720
  14. WebClientRepeating_LAN8720

Example Async_AdvancedWebServer

/*
   Currently support
   1) STM32 boards with built-in Ethernet (to use USE_BUILTIN_ETHERNET = true) such as :
      - Nucleo-144 (F429ZI, F767ZI)
      - Discovery (STM32F746G-DISCOVERY)
      - STM32 boards (STM32F/L/H/G/WB/MP1) with 32K+ Flash, with Built-in Ethernet, 
      - See How To Use Built-in Ethernet at (https://github.com/khoih-prog/EthernetWebServer_STM32/issues/1)
   2) STM32F/L/H/G/WB/MP1 boards (with 64+K Flash) running ENC28J60 shields (to use USE_BUILTIN_ETHERNET = false)
   3) STM32F/L/H/G/WB/MP1 boards (with 64+K Flash) running W5x00 shields
   4) STM32F4 and STM32F7 boards (with 64+K Flash) running LAN8720 shields
*/

#if !( defined(STM32F0) || defined(STM32F1) || defined(STM32F2) || defined(STM32F3)  ||defined(STM32F4) || defined(STM32F7) || \
       defined(STM32L0) || defined(STM32L1) || defined(STM32L4) || defined(STM32H7)  ||defined(STM32G0) || defined(STM32G4) || \
       defined(STM32WB) || defined(STM32MP1) )
  #error This code is designed to run on STM32F/L/H/G/WB/MP1 platform! Please check your Tools->Board setting.
#endif

#define _ASYNCWEBSERVER_STM32_LOGLEVEL_       4

#if defined(STM32F0)
  #warning STM32F0 board selected
  #define BOARD_TYPE  "STM32F0"
#elif defined(STM32F1)
  #warning STM32F1 board selected
  #define BOARD_TYPE  "STM32F1"
#elif defined(STM32F2)
  #warning STM32F2 board selected
  #define BOARD_TYPE  "STM32F2"
#elif defined(STM32F3)
  #warning STM32F3 board selected
  #define BOARD_TYPE  "STM32F3"
#elif defined(STM32F4)
  #warning STM32F4 board selected
  #define BOARD_TYPE  "STM32F4"
#elif defined(STM32F7)
  #warning STM32F7 board selected
  #define BOARD_TYPE  "STM32F7"
#elif defined(STM32L0)
  #warning STM32L0 board selected
  #define BOARD_TYPE  "STM32L0"
#elif defined(STM32L1)
  #warning STM32L1 board selected
  #define BOARD_TYPE  "STM32L1"
#elif defined(STM32L4)
  #warning STM32L4 board selected
  #define BOARD_TYPE  "STM32L4"
#elif defined(STM32H7)
  #warning STM32H7 board selected
  #define BOARD_TYPE  "STM32H7"
#elif defined(STM32G0)
  #warning STM32G0 board selected
  #define BOARD_TYPE  "STM32G0"
#elif defined(STM32G4)
  #warning STM32G4 board selected
  #define BOARD_TYPE  "STM32G4"
#elif defined(STM32WB)
  #warning STM32WB board selected
  #define BOARD_TYPE  "STM32WB"
#elif defined(STM32MP1)
  #warning STM32MP1 board selected
  #define BOARD_TYPE  "STM32MP1"
#else
  #warning STM32 unknown board selected
  #define BOARD_TYPE  "STM32 Unknown"
#endif

#ifndef BOARD_NAME
  #define BOARD_NAME    BOARD_TYPE
#endif

#define SHIELD_TYPE     "LAN8742A built-in Ethernet"

#include <LwIP.h>
#include <STM32Ethernet.h>
#include <AsyncWebServer_STM32.h>

// Enter a MAC address and IP address for your controller below.
#define NUMBER_OF_MAC      20

byte mac[][NUMBER_OF_MAC] =
{
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x01 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x02 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x03 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x04 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x05 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x06 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x07 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x08 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x09 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0A },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0B },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0C },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0D },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0E },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0F },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x10 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x11 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x12 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x13 },
  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x14 },
};
// Select the IP address according to your local network
IPAddress ip(192, 168, 2, 232);

AsyncWebServer    server(80);

int reqCount = 0;                // number of requests received

const int led = 13;

void handleRoot(AsyncWebServerRequest *request)
{
  digitalWrite(led, 1);

#define BUFFER_SIZE     400

  char temp[BUFFER_SIZE];
  int sec = millis() / 1000;
  int min = sec / 60;
  int hr = min / 60;
  int day = hr / 24;

  snprintf(temp, BUFFER_SIZE - 1,
           "<html>\
<head>\
<meta http-equiv='refresh' content='5'/>\
<title>AsyncWebServer-%s</title>\
<style>\
body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
</style>\
</head>\
<body>\
<h2>AsyncWebServer_STM32!</h2>\
<h3>running on %s</h3>\
<p>Uptime: %d d %02d:%02d:%02d</p>\
<img src=\"/test.svg\" />\
</body>\
</html>", BOARD_NAME, BOARD_NAME, day, hr % 24, min % 60, sec % 60);

  request->send(200, "text/html", temp);

  digitalWrite(led, 0);
}

void handleNotFound(AsyncWebServerRequest *request)
{
  digitalWrite(led, 1);
  String message = "File Not Found\n\n";

  message += "URI: ";
  message += request->url();
  message += "\nMethod: ";
  message += (request->method() == HTTP_GET) ? "GET" : "POST";
  message += "\nArguments: ";
  message += request->args();
  message += "\n";

  for (uint8_t i = 0; i < request->args(); i++)
  {
    message += " " + request->argName(i) + ": " + request->arg(i) + "\n";
  }

  request->send(404, "text/plain", message);
  digitalWrite(led, 0);
}

void drawGraph(AsyncWebServerRequest *request)
{
  String out;

  out.reserve(3000);
  char temp[70];
  
  out += "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" width=\"310\" height=\"150\">\n";
  out += "<rect width=\"310\" height=\"150\" fill=\"rgb(250, 230, 210)\" stroke-width=\"2\" stroke=\"rgb(0, 0, 0)\" />\n";
  out += "<g stroke=\"blue\">\n";
  int y = rand() % 130;

  for (int x = 10; x < 300; x += 10)
  {
    int y2 = rand() % 130;
    sprintf(temp, "<line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke-width=\"2\" />\n", x, 140 - y, x + 10, 140 - y2);
    out += temp;
    y = y2;
  }
  out += "</g>\n</svg>\n";

  request->send(200, "image/svg+xml", out);
}


void setup(void)
{
  pinMode(led, OUTPUT);
  digitalWrite(led, 0);

  Serial.begin(115200);
  while (!Serial);

  delay(200);

  Serial.print("\nStart Async_AdvancedWebServer_STM32 on "); Serial.print(BOARD_NAME);
  Serial.print(" with "); Serial.println(SHIELD_TYPE);
  Serial.println(ASYNC_WEBSERVER_STM32_VERSION);

  // start the ethernet connection and the server
  // Use random mac
  uint16_t index = millis() % NUMBER_OF_MAC;

  // Use Static IP
  //Ethernet.begin(mac[index], ip);
  // Use DHCP dynamic IP and random mac
  Ethernet.begin(mac[index]);

  server.on("/", HTTP_GET, [](AsyncWebServerRequest * request)
  {
    handleRoot(request);
  });

  server.on("/test.svg", HTTP_GET, [](AsyncWebServerRequest * request)
  {
    drawGraph(request);
  });

  server.on("/inline", [](AsyncWebServerRequest * request)
  {
    request->send(200, "text/plain", "This works as well");
  });

  server.onNotFound(handleNotFound);

  server.begin();

  Serial.print(F("HTTP EthernetWebServer is @ IP : "));
  Serial.println(Ethernet.localIP());
}

void loop(void)
{
}

You can access the Async Advanced WebServer @ the server IP

Debug Termimal Output Samples

1. AsyncMultiWebServer_STM32 on NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library

Following are debug terminal output and screen shots when running example AsyncMultiWebServer_STM32 on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library to demonstrate the operation of 3 independent AsyncWebServers on 3 different ports and how to handle the complicated AsyncMultiWebServers.

Starting AsyncMultiWebServer_STM32 on NUCLEO_F767ZI with LAN8742A built-in Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.141
Initialize multiServer OK, serverIndex = 0, port = 8080
HTTP server started at ports 8080
Initialize multiServer OK, serverIndex = 1, port = 8081
HTTP server started at ports 8081
Initialize multiServer OK, serverIndex = 2, port = 8082
HTTP server started at ports 8082

You can access the Async Advanced WebServers @ the server IP and corresponding ports (8080, 8081 and 8082)

2. WebClient on NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library

Following is debug terminal output when running example WebClient on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library.

Starting WebClient on NUCLEO_F767ZI with LAN8742A built-in Ethernet
AsyncWebServer_STM32 v1.4.1
You're connected to the network, IP = 192.168.2.71

Starting connection to server...
Connected to server
HTTP/1.1 200 OK
Server: nginx/1.4.2
Date: Mon, 28 Dec 2020 22:30:39 GMT
Content-Type: text/plain
Content-Length: 2263
Last-Modified: Wed, 02 Oct 2013 13:46:47 GMT
Connection: close
Vary: Accept-Encoding
ETag: "524c23c7-8d7"
Accept-Ranges: bytes


           `:;;;,`                      .:;;:.           
        .;;;;;;;;;;;`                :;;;;;;;;;;:     TM 
      `;;;;;;;;;;;;;;;`            :;;;;;;;;;;;;;;;      
     :;;;;;;;;;;;;;;;;;;         `;;;;;;;;;;;;;;;;;;     
    ;;;;;;;;;;;;;;;;;;;;;       .;;;;;;;;;;;;;;;;;;;;    
   ;;;;;;;;:`   `;;;;;;;;;     ,;;;;;;;;.`   .;;;;;;;;   
  .;;;;;;,         :;;;;;;;   .;;;;;;;          ;;;;;;;  
  ;;;;;;             ;;;;;;;  ;;;;;;,            ;;;;;;. 
 ,;;;;;               ;;;;;;.;;;;;;`              ;;;;;; 
 ;;;;;.                ;;;;;;;;;;;`      ```       ;;;;;`
 ;;;;;                  ;;;;;;;;;,       ;;;       .;;;;;
`;;;;:                  `;;;;;;;;        ;;;        ;;;;;
,;;;;`    `,,,,,,,,      ;;;;;;;      .,,;;;,,,     ;;;;;
:;;;;`    .;;;;;;;;       ;;;;;,      :;;;;;;;;     ;;;;;
:;;;;`    .;;;;;;;;      `;;;;;;      :;;;;;;;;     ;;;;;
.;;;;.                   ;;;;;;;.        ;;;        ;;;;;
 ;;;;;                  ;;;;;;;;;        ;;;        ;;;;;
 ;;;;;                 .;;;;;;;;;;       ;;;       ;;;;;,
 ;;;;;;               `;;;;;;;;;;;;                ;;;;; 
 `;;;;;,             .;;;;;; ;;;;;;;              ;;;;;; 
  ;;;;;;:           :;;;;;;.  ;;;;;;;            ;;;;;;  
   ;;;;;;;`       .;;;;;;;,    ;;;;;;;;        ;;;;;;;:  
    ;;;;;;;;;:,:;;;;;;;;;:      ;;;;;;;;;;:,;;;;;;;;;;   
    `;;;;;;;;;;;;;;;;;;;.        ;;;;;;;;;;;;;;;;;;;;    
      ;;;;;;;;;;;;;;;;;           :;;;;;;;;;;;;;;;;:     
       ,;;;;;;;;;;;;;,              ;;;;;;;;;;;;;;       
         .;;;;;;;;;`                  ,;;;;;;;;:         
                                                         
                                                         
                                                         
                                                         
    ;;;   ;;;;;`  ;;;;:  .;;  ;; ,;;;;;, ;;. `;,  ;;;;   
    ;;;   ;;:;;;  ;;;;;; .;;  ;; ,;;;;;: ;;; `;, ;;;:;;  
   ,;:;   ;;  ;;  ;;  ;; .;;  ;;   ,;,   ;;;,`;, ;;  ;;  
   ;; ;:  ;;  ;;  ;;  ;; .;;  ;;   ,;,   ;;;;`;, ;;  ;;. 
   ;: ;;  ;;;;;:  ;;  ;; .;;  ;;   ,;,   ;;`;;;, ;;  ;;` 
  ,;;;;;  ;;`;;   ;;  ;; .;;  ;;   ,;,   ;; ;;;, ;;  ;;  
  ;;  ,;, ;; .;;  ;;;;;:  ;;;;;: ,;;;;;: ;;  ;;, ;;;;;;  
  ;;   ;; ;;  ;;` ;;;;.   `;;;:  ,;;;;;, ;;  ;;,  ;;;;   

Disconnecting from server...

3. MQTTClient_Auth on NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library

Following is debug terminal output when running example MQTTClient_Auth on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library.

Starting MQTTClient_Auth on NUCLEO_F767ZI with LAN8742A built-in Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.71
Attempting MQTT connection to broker.emqx.io...connected
Message Send : MQTT_Pub => Hello from MQTTClient_Auth on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth on NUCLEO_F767ZI with LAN8742A built-in Ethernet

4. MQTTClient_Basic on NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library

Following is debug terminal output when running example MQTTClient_Basic on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library.

Starting MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.71
Attempting MQTT connection to broker.shiftr.io...connected
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on NUCLEO_F767ZI with LAN8742A built-in Ethernet

5. MQTT_ThingStream on NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library

Following is debug terminal output when running example MQTT_ThingStream on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library.

Starting MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.71
***************************************
STM32_Pub
***************************************
Attempting MQTT connection to broker.emqx.io
...connected
Published connection message successfully!
Subcribed to: STM32_Sub
MQTT Message Send : STM32_Pub => Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message receive [STM32_Pub] Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message Send : STM32_Pub => Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message receive [STM32_Pub] Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message Send : STM32_Pub => Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message receive [STM32_Pub] Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message Send : STM32_Pub => Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message receive [STM32_Pub] Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message Send : STM32_Pub => Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet
MQTT Message receive [STM32_Pub] Hello from MQTT_ThingStream on NUCLEO_F767ZI with LAN8742A built-in Ethernet

6. MQTTClient_Auth_LAN8720 on BLACK_F407VE using LAN8720 Ethernet and STM32Ethernet Library

Following is debug terminal output when running example MQTTClient_Auth_LAN8720 on STM32F4 BLACK_F407VE with LAN8720 Ethernet and STM32Ethernet Library.

Start MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.150
Attempting MQTT connection to broker.emqx.io...connected
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message Send : MQTT_Pub => Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth_LAN8720 on BLACK_F407VE with LAN8720 Ethernet

7. Async_AdvancedWebServer_LAN8720 on BLACK_F407VE using LAN8720 Ethernet and STM32Ethernet Library

Following is the screen shot when running example Async_AdvancedWebServer_LAN8720 on STM32F4 BLACK_F407VE with LAN8720 Ethernet and STM32Ethernet Library to demonstrate the operation of AsyncWebServer.

8. AsyncMultiWebServer_STM32_LAN8720 on BLACK_F407VE using LAN8720 Ethernet and STM32Ethernet Library

Following are debug terminal output and screen shots when running example AsyncMultiWebServer_STM32_LAN8720 on STM32F4 BLACK_F407VE with LAN8720 Ethernet and STM32Ethernet Library to demonstrate the operation of 3 independent AsyncWebServers on 3 different ports and how to handle the complicated AsyncMultiWebServers.

Start AsyncMultiWebServer_STM32_LAN8720 on BLACK_F407VE with LAN8720 Ethernet
AsyncWebServer_STM32 v1.4.1

Connected to network. IP = 192.168.2.150
Initialize multiServer OK, serverIndex = 0, port = 8080
HTTP server started at ports 8080
Initialize multiServer OK, serverIndex = 1, port = 8081
HTTP server started at ports 8081
Initialize multiServer OK, serverIndex = 2, port = 8082
HTTP server started at ports 8082

You can access the Async Advanced WebServers @ the server IP and corresponding ports (8080, 8081 and 8082)

Debug

Debug is enabled by default on Serial. Debug Level from 0 to 4. To disable, change the ETHERNET_WEBSERVER_LOGLEVEL to 0

// Use this to output debug msgs to Serial
#define ASYNCWEBSERVER_STM32_DEBUG_PORT       Serial
// Use this to disable all output debug msgs
// Debug Level from 0 to 4
#define _ASYNCWEBSERVER_STM32_LOGLEVEL_       0

Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of Arduino IDE, the Arduino STM32 core or depending libraries.

Sometimes, the library will only work if you update the STM32 core to the latest version because I'm always using the latest cores /libraries.

If you connect to the created configuration Access Point but the ConfigPortal does not show up, just open a browser and type in the IP of the web portal, by default 192.168.4.1.

Issues

Submit issues to: AsyncWebServer_STM32 issues

TO DO

  1. Fix bug. Add enhancement
  2. Add support to more Ethernet / WiFi shield
  3. Add support to more STM32 boards.
  4. Add support to File using STM32-SD or STM32-FS.

DONE

  1. Initial port to STM32 using builtin LAN8742A Etnernet. Tested on STM32F7 Nucleo-144 F767ZI.
  2. Add more examples.
  3. Add debugging features.
  4. Add AsyncUDP_STM32 to support Async UDP on STM32
  5. Add Authentication support (MD5, SHA1).
  6. Add support to Ethernet LAN8720 using STM32Ethernet library, for boards such as Nucleo-144 (F429ZI, NUCLEO_F746NG, NUCLEO_F746ZG, NUCLEO_F756ZG), Discovery (DISCO_F746NG) and STM32F4 boards (BLACK_F407VE, BLACK_F407VG, BLACK_F407ZE, BLACK_F407ZG, BLACK_F407VE_Mini, DIYMORE_F407VGT, FK407M1). Tested on STM32F4 BLACK_F407VE.
  7. Add Table-of-Contents and Version String

Contributions and Thanks

  1. Based on and modified from Hristo Gochkov's ESPAsyncWebServer. Many thanks to Hristo Gochkov for great ESPAsyncWebServer Library
  2. Relied on Frederic Pillon's STM32duino LwIP Library.
  3. Relied on PhilBowles' STM32 AsyncTCP Library.
  4. Thanks to good work of Miguel Wisintainer for working with, developing, debugging and testing.
  5. Thanks to Jean-Claude and chris007de to help locate the dependency issue, discuss solution leading to release v1.2.6. Check Compilation broken due to error in STM32AsyncTCP dependency and how to run one of the examples?.
  6. Thanks to tothtechnika to create the PR Fix base64 encoding of websocket client key and progmem support for webserver #7 leading to new release v1.4.0
me-no-dev
⭐️⭐️ Hristo Gochkov
 fpistm
⭐️ Frederic Pillon
 philbowles
⭐️ Phil Bowles
 tcpipchip
tcpipchip
 jcw
Jean-Claude
 chris007de
chris007de
tothtechnika
tothtechnika

Contributing

If you want to contribute to this project:

  • Report bugs and errors
  • Ask for enhancements
  • Create issues and pull requests
  • Tell other people about this library

License

  • The library is licensed under MIT

Copyright

Copyright 2020- Khoi Hoang