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khoih-prog / AsyncWebServer_RP2040W

Asynchronous WebServer Library for RASPBERRY_PI_PICO_W using CYW43439 WiFi with arduino-pico core. This library, which is relied on AsyncTCP_RP2040W, is part of a series of advanced Async libraries for RP2040W, such as AsyncTCP_RP2040W, AsyncUDP_RP2040W, AsyncWebServer_RP2040W, AsyncHTTPRequest_RP2040W, AsyncHTTPSRequest_RP2040W, etc. Now can display programmed WiFi country-code and support using CString to save heap to send very large data
GNU Lesser General Public License v3.0
25 stars 7 forks source link
async-events async-tcp async-tcp-client async-tcp-server async-tcp-webserver async-webserver async-websockets asynchronous cyw43439 fs-webserver littlefs raspberry-pi-pico-w rp2040 rp2040w tcp-client tcp-ip tcp-server webserver websockets wifi

readme

AsyncWebServer_RP2040W

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Table of contents

Important Note from v1.4.0

The new v1.4.0+ has added a new and powerful feature to use LittleFS functions, such as AsyncFSWebServer

Check these new examples

  1. AsyncFSWebServer
  2. AsyncFSWebServer_Complex

Important Note from v1.2.0

The new v1.2.0+ has added a new and powerful feature to permit using CString to save heap to send very large data.

Check the marvelleous PRs of @salasidis in Portenta_H7_AsyncWebServer library

and these new examples

  1. Async_AdvancedWebServer_MemoryIssues_Send_CString
  2. Async_AdvancedWebServer_MemoryIssues_SendArduinoString

If using Arduino String, to send a buffer around 30 KBytes, the used Max Heap is around 75,264 bytes

If using CString in regular memory, with the same 30 KBytes, the used Max Heap is around 44,000 bytes, saving around a buffer size (30 KBytes)

This is very critical in use-cases where sending very large data is necessary, without heap-allocation-error.

  1. The traditional function used to send Arduino String is

https://github.com/khoih-prog/AsyncWebServer_RP2040W/blob/e98fdf0f1aa79f17071822522cb1a50ce4fdf6f4/src/AsyncWebServer_RP2040W.h#L414

void send(int code, const String& contentType = String(), const String& content = String());

such as

request->send(200, textPlainStr, ArduinoStr);

The required additional HEAP is about 3 times of the String size

  1. To use CString with copying while sending. Use function

https://github.com/khoih-prog/AsyncWebServer_RP2040W/blob/e98fdf0f1aa79f17071822522cb1a50ce4fdf6f4/src/AsyncWebServer_RP2040W.h#L415

void send(int code, const String& contentType, const char *content, bool nonDetructiveSend = true);    // RSMOD

such as 

request->send(200, textPlainStr, cStr);

The required additional HEAP is also about 2 times of the CString size because of unnecessary copies of the CString in HEAP. Avoid this unefficient way.

  1. To use CString without copying while sending. Use function

https://github.com/khoih-prog/AsyncWebServer_RP2040W/blob/e98fdf0f1aa79f17071822522cb1a50ce4fdf6f4/src/AsyncWebServer_RP2040W.h#L415

void send(int code, const String& contentType, const char *content, bool nonDetructiveSend = true);    // RSMOD

such as 

request->send(200, textPlainStr, cStr, false);

The required additional HEAP is about 1 times of the CString size. This way is the best and most efficient way to use by avoiding of unnecessary copies of the CString in HEAP

Why do we need this AsyncWebServer_RP2040W 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 RASPBERRY_PI_PICO_W. Thus AsyncWebServer_RP2040W is part of a series of advanced Async libraries, such as AsyncTCP_RP2040W, AsyncUDP_RP2040W, AsyncWebServer_RP2040W, AsyncHTTPRequest_RP2040W, AsyncHTTPSRequest_RP2040W, etc. to be written or modified to support RASPBERRY_PI_PICO_W, using CYW43439 WiFi.

Why Async is better

Currently supported Boards

  1. RASPBERRY_PI_PICO_W with CYW43439 WiFi using arduino-pico core v2.4.0+

Prerequisites

  1. Arduino IDE 1.8.19+ for Arduino. GitHub release
  2. Earle Philhower's arduino-pico core v2.7.1+ for RASPBERRY_PI_PICO_W with CYW43439 WiFi, etc. GitHub release
  3. AsyncTCP_RP2040W library v1.1.0+ for RASPBERRY_PI_PICO_W with CYW43439 WiFi. GitHub release
  4. AsyncMQTT_Generic library v1.8.1+ to use with some examples. GitHub release

Installation

Use Arduino Library Manager

The best and easiest way is to use Arduino Library Manager. Search for AsyncWebServer_RP2040W, 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_RP2040W page.
  2. Download the latest release AsyncWebServer_RP2040W-main.zip.
  3. Extract the zip file to AsyncWebServer_RP2040W-main directory
  4. Copy the whole AsyncWebServer_RP2040W-main folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO:

  1. Install VS Code
  2. Install PlatformIO
  3. Install AsyncWebServer_RP2040W library by using Library Manager. Search for AsyncWebServer_RP2040W 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

Important things to remember

Principles of operation

The Async Web server

Request Life Cycle

Rewrites and how do they work

Handlers and how do they work

Responses and how do they work

Template processing

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 available in Handler::canHandle)
request->contentLength(); // size_t:  ContentLength of the request (not available 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_RP2040W");
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_RP2040W");
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_RP2040W");
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_RP2040W");
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_RP2040W");
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_RP2040W");
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_RP2040W");
request->send(response);

Print to response

AsyncResponseStream *response = request->beginResponseStream("text/html");
response->addHeader("Server","AsyncWebServer_RP2040W");
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 websocket 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

#if !( defined(ARDUINO_RASPBERRY_PI_PICO_W) )
  #error For RASPBERRY_PI_PICO_W only
#endif

#include <AsyncWebServer_RP2040W.h>

char ssid[] = "your_ssid";        // your network SSID (name)
char pass[] = "12345678";         // your network password (use for WPA, or use as key for WEP), length must be 8+

int status = WL_IDLE_STATUS;

AsyncWebServer    server(80);

#define LED_OFF             LOW
#define LED_ON              HIGH

#define BUFFER_SIZE         64
char temp[BUFFER_SIZE];

void handleRoot(AsyncWebServerRequest *request)
{
  digitalWrite(LED_BUILTIN, LED_ON);

  snprintf(temp, BUFFER_SIZE - 1, "Hello from Async_HelloServer on %s\n", BOARD_NAME);

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

  digitalWrite(LED_BUILTIN, LED_OFF);
}

void handleNotFound(AsyncWebServerRequest *request)
{
  digitalWrite(LED_BUILTIN, LED_ON);

  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_BUILTIN, LED_OFF);
}

void printWifiStatus()
{
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your board's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("Local IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm");
}

void setup()
{
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LED_OFF);

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

  delay(200);

  Serial.print("\nStart Async_HelloServer on "); Serial.print(BOARD_NAME);
  Serial.print(" with "); Serial.println(SHIELD_TYPE);
  Serial.println(ASYNCTCP_RP2040W_VERSION);
  Serial.println(ASYNC_WEBSERVER_RP2040W_VERSION);

  ///////////////////////////////////

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE)
  {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  Serial.print(F("Connecting to SSID: "));
  Serial.println(ssid);

  status = WiFi.begin(ssid, pass);

  delay(1000);

  // attempt to connect to WiFi network
  while ( status != WL_CONNECTED)
  {
    delay(500);

    // Connect to WPA/WPA2 network
    status = WiFi.status();
  }

  printWifiStatus();

  ///////////////////////////////////

  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(WiFi.localIP());
}

void heartBeatPrint()
{
  static int num = 1;

  Serial.print(F("."));

  if (num == 80)
  {
    Serial.println();
    num = 1;
  }
  else if (num++ % 10 == 0)
  {
    Serial.print(F(" "));
  }
}

void check_status()
{
  static unsigned long checkstatus_timeout = 0;

#define STATUS_CHECK_INTERVAL     10000L

  // Send status report every STATUS_REPORT_INTERVAL (60) seconds: we don't need to send updates frequently if there is no status change.
  if ((millis() > checkstatus_timeout) || (checkstatus_timeout == 0))
  {
    heartBeatPrint();
    checkstatus_timeout = millis() + STATUS_CHECK_INTERVAL;
  }
}

void loop()
{
  check_status();
}

Setup global and class functions as request handlers

#if !( defined(ARDUINO_RASPBERRY_PI_PICO_W) )
  #error For RASPBERRY_PI_PICO_W only
#endif

#include <Arduino.h>

#include <AsyncWebServer_RP2040W.h>

char ssid[] = "your_ssid";        // your network SSID (name)
char pass[] = "12345678";         // your network password (use for WPA, or use as key for WEP), length must be 8+

int status = WL_IDLE_STATUS;

#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\{xxxx}\hardware\xxxx\{version}\platform.local.txt

Linux: ~/.arduino15/packages/{xxxx}/hardware/{xxxx}/{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.

Examples

  1. Async_AdvancedWebServer
  2. Async_HelloServer
  3. Async_HelloServer2
  4. Async_HttpBasicAuth
  5. Async_PostServer
  6. MQTTClient_Auth
  7. MQTTClient_Basic
  8. MQTT_ThingStream
  9. WebClient
    1. WebClientRepeating
    2. Async_AdvancedWebServer_Country
    3. Async_AdvancedWebServer_favicon
    4. Async_AdvancedWebServer_MemoryIssues_SendArduinoString
    5. Async_AdvancedWebServer_MemoryIssues_Send_CString
    6. Async_WebSocketsServer
    7. Async_WebSocketsServer_Xtreme
    8. AsyncFSWebServer
    9. AsyncFSWebServer_Complex
    10. Async_AdvancedWebServer_SendChunked
    11. AsyncWebServer_SendChunked
    12. AsyncWebServer_MQTT_RP2040W New
    13. Async_AdvancedWebServer_SendChunked_MQTT New

Example Async_AdvancedWebServer

https://github.com/khoih-prog/AsyncWebServer_RP2040W/blob/2d2f55326766dc79340d906d6a4a386e4291e74e/examples/Async_AdvancedWebServer/Async_AdvancedWebServer.ino#L41-L299

You can access the Async Advanced WebServer @ the server IP

Debug Terminal Output Samples

1. Async_AdvancedWebServer on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is the debug terminal when running example Async_AdvancedWebServer on RASPBERRY_PI_PICO_W using CYW43439 WiFi to demonstrate the operation of AsyncWebServer_RP2040W, based on this AsyncTCP_RP2040W Library

Start Async_AdvancedWebServer on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA
HTTP EthernetWebServer is @ IP : 192.168.2.180
.......... .......... .......... .......... .......... .......... .......... ..........
.......... .......... .......... .......... .......... ...

2. WebClient on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example WebClient on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Start WebClient on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA

Starting connection to server...
Connected to server
HTTP/1.1 200 OK
Date: Tue, 16 Aug 2022 01:06:29 GMT
Content-Type: text/plain
Content-Length: 2263
Connection: close
x-amz-id-2: eCCq3bjp3ZIWsEqS9Timqjnr4liaTs2BY2giqfjPt5fRD9UPsPHZgIkhWMmbgfXHm7Rp6g1V1EE=
x-amz-request-id: V2X8BFCZS6E01EA4
Last-Modified: Wed, 23 Feb 2022 14:56:42 GMT
ETag: "667cf48afcc12c38c8c1637947a04224"
CF-Cache-Status: DYNAMIC
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=VUTYgtuhcRcBq%2F%2Bj6oRv60yx72aRGR6Z0yNupDNmxvSYpiwM6bHwRA8Xteiu3GM0pjxLcOGB5apbpNOkljur%2FuuNTU%2FnfcLZZc8zF7i8nrDyeplpCRDuJ9oz0HCZKSI%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
Server: cloudflare
CF-RAY: 73b64482ad06a1e0-YYZ
alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400

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

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

Disconnecting from server...

3. MQTTClient_Auth on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example MQTTClient_Auth on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Start MQTTClient_Auth on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA
Attempting MQTT connection to broker.emqx.io...connected
Message Send : MQTT_Pub => Hello from MQTTClient_Auth on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message Send : MQTT_Pub => Hello from MQTTClient_Auth on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message arrived [MQTT_Pub] Hello from MQTTClient_Auth on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi

4. MQTTClient_Basic on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example MQTTClient_Basic on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Start MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA
Attempting MQTT connection to broker.emqx.io...connected
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message arrived [MQTT_Pub] Hello from MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
Message Send : MQTT_Pub => Hello from MQTTClient_Basic on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi

5. MQTT_ThingStream on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example MQTT_ThingStream on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Start MQTT_ThingStream on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA
***************************************
RP2040W_Pub
***************************************
Attempting MQTT connection to broker.emqx.io
...connected
Published connection message successfully!
Subscribed to: RP2040W_Sub
MQTT Message Send : RP2040W_Pub => Hello from MQTT_ThingStream on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
MQTT Message receive [RP2040W_Pub] Hello from MQTT_ThingStream on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
MQTT Message Send : RP2040W_Pub => Hello from MQTT_ThingStream on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
MQTT Message receive [RP2040W_Pub] Hello from MQTT_ThingStream on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi

6. Async_AdvancedWebServer_Country on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is the debug terminal when running example Async_AdvancedWebServer_Country on RASPBERRY_PI_PICO_W using CYW43439 WiFi to demonstrate the operation of AsyncWebServer_RP2040W, based on this AsyncTCP_RP2040W Library and to display programmed country-code

Start Async_AdvancedWebServer_Country on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.180
Country code: CA         <================ Country code CA for CYW43_COUNTRY_CANADA
HTTP EthernetWebServer is @ IP : 192.168.2.180
....

Chrome, Vivaldi and Firefox running simultaneously

Only Firefox running

7. Async_AdvancedWebServer_favicon on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is the debug terminal when running example Async_AdvancedWebServer_favicon on RASPBERRY_PI_PICO_W using CYW43439 WiFi to demonstrate the operation of AsyncWebServer_RP2040W, based on this AsyncTCP_RP2040W Library and to display favicon.ico, which many browsers are interested.

14:22:06.632 -> Start Async_AdvancedWebServer_favicon on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
14:22:06.632 -> AsyncTCP_RP2040W v1.1.0
14:22:06.632 -> AsyncWebServer_RP2040W v1.5.0
14:22:06.632 -> Connecting to SSID: HueNet1
14:22:13.328 -> SSID: HueNet1
14:22:13.328 -> Local IP Address: 192.168.2.180
14:22:13.328 -> Country code: XX
14:22:13.328 -> HTTP EthernetWebServer is @ IP : 192.168.2.180
14:22:13.328 -> .......... .......... .......... .......... .......... .......... .......... ..........
14:35:53.414 -> .......... .......... .......... .......... ...

You can see the favicon.ico at the upper left corner

On Chrome

On Firefox

8. Async_AdvancedWebServer_MemoryIssues_Send_CString on RASPBERRY_PI_PICO_W

Following is the debug terminal and screen shot when running example Async_AdvancedWebServer_MemoryIssues_Send_CString on RASPBERRY_PI_PICO_W to demonstrate the new and powerful HEAP-saving feature

Using CString ===> small heap (44,000 bytes)
Start Async_AdvancedWebServer_MemoryIssues_Send_CString on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.74
Country code: XX
HTTP EthernetWebServer is @ IP : 192.168.2.74

HEAP DATA - Pre Create Arduino String  Cur heap: 193000  Free heap: 150928  Max heap: 42072
.75264
HEAP DATA - Pre Send  Cur heap: 193000  Free heap: 149176  Max heap: 43824

HEAP DATA - Post Send  Cur heap: 193000  Free heap: 149016  Max heap: 43984
.
HEAP DATA - Post Send  Cur heap: 193000  Free heap: 149000  Max heap: 44000
.......... .......... .......... ........
Out String Length=31247
.. .......... .......... .......... ..........

While using Arduino String, the HEAP usage is very large

Async_AdvancedWebServer_MemoryIssues_SendArduinoString ===> very large heap (75,264 bytes)

Start Async_AdvancedWebServer_MemoryIssues_SendArduinoString on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.74
Country code: XX
HTTP EthernetWebServer is @ IP : 192.168.2.74

HEAP DATA - Pre Create Arduino String  Cur heap: 193256  Free heap: 191192  Max heap: 2064
.
HEAP DATA - Pre Send  Cur heap: 193256  Free heap: 149432  Max heap: 43824

HEAP DATA - Post Send  Cur heap: 193256  Free heap: 118024  Max heap: 75232

HEAP DATA - Post Send  Cur heap: 193256  Free heap: 117992  Max heap: 75264
....... .......... .......... ..........
.......... .......... .......... ........
Out String Length=31247
.. .......... .

You can access the Async Advanced WebServers at the displayed server IP, e.g. 192.168.2.74

9. Async_WebSocketsServer on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example Async_WebSocketsServer on RASPBERRY_PI_PICO_W using CYW43439 WiFi. The WSClient is using the provided WSClient.py

Starting Async_WebSocketsServer on RASPBERRY_PI_PICO_W
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.77
ws[Server: /ws][ClientID: 1] WSClient connected
ws[Server: /ws][ClientID: 2] WSClient connected
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 1] WSClient disconnected
ws[Server: /ws][ClientID: 3] WSClient connected
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server
ws[Server: /ws][ClientID: 2] text-message[len: 13]: Hello, Server

You can access the Async_WebSockets Servers at the displayed server IP, e.g. 192.168.2.77

10. Async_WebSocketsServer_Xtreme on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example Async_WebSocketsServer_Xtreme on RASPBERRY_PI_PICO_W using CYW43439 WiFi.

Starting Async_WebSocketsServer_Xtreme on RASPBERRY_PI_PICO_W
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.77

You can access the Async_WebSockets Servers at the displayed server IP, e.g. 192.168.2.77

11. AsyncFSWebServer_Complex on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example AsyncFSWebServer_Complex on RASPBERRY_PI_PICO_W using CYW43439 WiFi.

Start AsyncFSWebServer_Complex on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.77
Opening / directory
FS File: CanadaFlag_1.png, size: 40.25KB
FS File: CanadaFlag_2.png, size: 8.12KB
FS File: CanadaFlag_3.jpg, size: 10.89KB
FS File: css, size: 0B
FS File: edit.htm.gz, size: 4.02KB
FS File: favicon.ico, size: 1.12KB
FS File: graphs.js.gz, size: 1.92KB
FS File: index.htm, size: 3.63KB
FS File: js, size: 0B

AsyncWebServer started @192.168.2.77
Open http://192.168.2.77/edit to see the file browser
AsyncFSEditor::handleRequest: Sending AsyncWebServerResponse

You can access the Async_WebSockets Servers at the displayed server IP, e.g. 192.168.2.77

12. Async_AdvancedWebServer_SendChunked on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example Async_AdvancedWebServer_SendChunked on RASPBERRY_PI_PICO_W using CYW43439 WiFi, to demo how to use beginChunkedResponse() to send large html in chunks

Start Async_AdvancedWebServer_SendChunked on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.77
Country code: XX
AsyncWebServer is @ IP : 192.168.2.77
.[AWS] Total length to send in chunks = 31259
[AWS] Bytes sent in chunk = 11556
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 8031
[AWS] Bytes sent in chunk = 0
[AWS] Total length to send in chunks = 31279
[AWS] Bytes sent in chunk = 11556
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 8051
[AWS] Bytes sent in chunk = 0

You can access the AsyncWebServer_RP2040W at the displayed server IP, e.g. 192.168.2.77

13. AsyncWebServer_SendChunked on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example AsyncWebServer_SendChunked onRASPBERRY_PI_PICO_W using CYW43439 WiFi, to demo how to use beginChunkedResponse() to send large html in chunks

Start AsyncWebServer_SendChunked on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.77
Country code: XX
AsyncWebServer is @ IP : 192.168.2.77
.[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 811
[AWS] Bytes sent in chunk = 0
.[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 811
[AWS] Bytes sent in chunk = 0
[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 811
[AWS] Bytes sent in chunk = 0
.[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 811
[AWS] Bytes sent in chunk = 0
[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 11672
[AWS] Bytes sent in chunk = 811
[AWS] Bytes sent in chunk = 0
.[AWS] Total length to send in chunks = 47387
[AWS] Bytes sent in chunk = 11560
...... ...

14. Async_AdvancedWebServer_SendChunked_MQTT on RASPBERRY_PI_PICO_W using CYW43439 WiFi

Following is debug terminal output when running example Async_AdvancedWebServer_SendChunked_MQTT on RASPBERRY_PI_PICO_W using CYW43439 WiFi, to demo how to use AsyncWebServer_RP2040W and AsyncMQTT_Generic libraries together

Start Async_AdvancedWebServer_SendChunked_MQTT on RASPBERRY_PI_PICO_W with RP2040W CYW43439 WiFi
AsyncTCP_RP2040W v1.1.0
AsyncWebServer_RP2040W v1.5.0
AsyncMQTT_Generic v1.8.1 for RP2040W CYW43439 WiFi
Connecting to SSID: HueNet
SSID: HueNet
Local IP Address: 192.168.2.128
Country code: XX
Connecting to MQTT...
AsyncWebServer is @ IP : 192.168.2.128
.Connected to MQTT broker: broker.emqx.io, port: 1883
PubTopic: async-mqtt/RP2040W_Pub
************************************************
Session present: 0
Subscribing at QoS 2, packetId: 1
Publishing at QoS 0
Publishing at QoS 1, packetId: 2
Publishing at QoS 2, packetId: 3
************************************************
Subscribe acknowledged.
  packetId: 1
  qos: 2
Publish received.
  topic: async-mqtt/RP2040W_Pub
  message: RP2040W Test3
  qos: 2
  dup: 0
  retain: 1
  len: 13
  index: 0
  total: 13
Publish acknowledged.
  packetId: 2
Publish received.
  topic: async-mqtt/RP2040W_Pub
  message: RP2040W Test1
  qos: 0
  dup: 0
  retain: 0
  len: 13
  index: 0
  total: 13
Publish received.
  topic: async-mqtt/RP2040W_Pub
  message: RP2040W Test2
  qos: 1
  dup: 0
  retain: 0
  len: 13
  index: 0
  total: 13
Publish received.
  topic: async-mqtt/RP2040W_Pub
  message: RP2040W Test3
  qos: 2
  dup: 0
  retain: 0
  len: 13
  index: 0
  total: 13
Publish acknowledged.
  packetId: 3
...Publish received.
  topic: async-mqtt/RP2040W_Pub
  message: RP2040W Test2
  qos: 1
  dup: 1
  retain: 0
  len: 13
  index: 0
  total: 13
..Disconnected from MQTT.
.... .......... .

You can access the AsyncWebServer_RP2040W at the displayed server IP, e.g. 192.168.2.128

Debug

Debug is enabled by default on Serial.

You can also change the debugging level _RP2040W_AWS_LOGLEVEL_ from 0 to 4 in the library cpp files

#define _RP2040W_AWS_LOGLEVEL_     1

Troubleshooting

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

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

Issues

Submit issues to: AsyncWebServer_RP2040W issues

TO DO

  1. Fix bug. Add enhancement

DONE

  1. Add support to RASPBERRY_PI_PICO_W using CYW43439 WiFi
  2. Add Table of Contents
  3. Modify examples to display country-code
  4. Add tempo method to modify arduino-pico core to change country-code
  5. Fix issue with slow browsers or network. Check Target stops responding after variable time when using Firefox on Windows 10 #3
  6. Add functions and example Async_AdvancedWebServer_favicon to support favicon.ico
  7. Support using CString to save heap to send very large data. Check request->send(200, textPlainStr, jsonChartDataCharStr); - Without using String Class - to save heap #8
  8. Fix crash when using AsyncWebSockets server and add example Async_WebSocketsServer to demo the AsyncWebSockets Server with a Python WSClient.py
  9. Improve robustness of AsyncWebSockets server. Check AsyncWebSocketServer_RP2040W crashes with "[AWS] ERROR: Too many messages queued" #6 and add example Async_WebSocketsServer_Xtreme to demo the nearly highest possible WebSockets Server speed
    1. Add LittleFS functions such as AsyncFSWebServer
    2. Add examples Async_AdvancedWebServer_SendChunked and AsyncWebServer_SendChunked to demo how to use beginChunkedResponse() to send large html in chunks
    3. Add examples Async_AdvancedWebServer_SendChunked_MQTT and AsyncWebServer_MQTT_RP2040W to demo how to use AsyncWebServer_RP2040W and AsyncMQTT_Generic libraries together
    4. Improve README.md so that links can be used in other sites, such as PIO

Contributions and Thanks

  1. Based on and modified from Hristo Gochkov's ESPAsyncWebServer. Many thanks to Hristo Gochkov for great ESPAsyncWebServer Library
  2. Thanks to revell1 to
  3. Thanks to salasidis aka rs77can to discuss and make the following marvellous PRs in Portenta_H7_AsyncWebServer library
  4. Thanks to drmue to report the bugs in
  5. Thanks to roma2580 to report and help fix the bug in
me-no-dev
⭐️⭐️ Hristo Gochkov
 revell1
revell1
 salasidis
⭐️ salasidis
 drmue
drmue
 roma2580
>⭐️ roma2580

Contributing

If you want to contribute to this project:

License

Copyright

Copyright 2022- Khoi Hoang