AsyncDNSServer_RP2040W Library

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Table of Contents

• Why do we need this AsyncDNSServer_RP2040W library
  • Features
  • Why Async is better
  • Currently Supported Boards
• Changelog
• Prerequisites
• Installation
  • Use Arduino Library Manager
  • Manual Install
  • VS Code & PlatformIO
• HOWTO Fix Multiple Definitions Linker Error
• HOWTO Setting up the Async DNS Server
• Examples
  • 1. AsyncCaptivePortal
  • 2. AsyncCaptivePortalAdvanced
  • 3. AsyncDNServerFull
  • 4. AsyncDNSServer
  • 5. multiFileProject
• Example AsyncDNSServer
  • 1. File AsyncDNSServer.ino
  • 2. File defines.h
• Debug
• Troubleshooting
• Issues
• TO DO
• DONE
• Contributions and Thanks
• Contributing
• License
• Copyright

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Why do we need this AsyncDNSServer_RP2040W library

Features

This AsyncDNSServer_RP2040W library is a fully asynchronous DNSServer library, designed for a trouble-free, multi-connection network environment, for RASPBERRY_PI_PICO_W using CYW43439 WiFi.

This library is based on, modified from:

1. Develo's ESPAsyncDNSServer
2. AsyncDNSServer_STM32

to apply the better and faster asynchronous feature into RASPBERRY_PI_PICO_W using CYW43439 WiFi.

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 packet is ready
• After a DNS Client connected to this Async DNS server, you are immediately ready to handle other connections while the Server is taking care of receiving and responding to the UDP packets in the background.
• You are not required to check in a tight loop() the arrival of the DNS requesting packets to process them.
• Speed is OMG

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Currently Supported Boards

1. RASPBERRY_PI_PICO_W with CYW43439 WiFi using arduino-pico core

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Prerequisites

1. Arduino IDE 1.8.19+ for Arduino.
2. Earle Philhower's arduino-pico core v2.6.3+ for RASPBERRY_PI_PICO_W with CYW43439 WiFi, etc.
3. AsyncUDP_RP2040W library v1.0.0+ for RASPBERRY_PI_PICO_W with CYW43439 WiFi. To install. check

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Installation

The suggested way to install is to:

Use Arduino Library Manager

The best way is to use Arduino Library Manager. Search for AsyncDNSServer_RP2040W, then select / install the latest version. You can also use this link for more detailed instructions.

Manual Install

1. Navigate to AsyncDNSServer_RP2040W page.
2. Download the latest release AsyncDNSServer_RP2040W-main.zip.
3. Extract the zip file to AsyncDNSServer_RP2040W-main directory
4. Copy the whole AsyncDNSServer_RP2040W-main folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO:

1. Install VS Code
2. Install PlatformIO
3. Install AsyncDNSServer_RP2040W library by using Library Manager. Search for AsyncDNSServer_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

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HOWTO Fix Multiple Definitions Linker Error

The current library implementation, using xyz-Impl.h instead of standard xyz.cpp, possibly creates certain Multiple Definitions Linker error in certain use cases.

You can include this .hpp file

// Can be included as many times as necessary, without `Multiple Definitions` Linker Error
#include "AsyncDNSServer_RP2040W.hpp"         //https://github.com/khoih-prog/AsyncDNSServer_RP2040W

in many files. But be sure to use the following .h file in just 1 .h, .cpp or .ino file, which must not be included in any other file, to avoid Multiple Definitions Linker Error

// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include "AsyncDNSServer_RP2040W.h"           //https://github.com/khoih-prog/AsyncDNSServer_RP2040W

Check the new multiFileProject example for a HOWTO demo.

Have a look at the discussion in Different behaviour using the src_cpp or src_h lib #80

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HOWTO Setting up the Async DNS Server

#include <AsyncDNSServer_RP2040W.h>

const byte DNS_PORT = 53;

IPAddress apIP;

AsyncDNSServer dnsServer;


void setup()
{
  ...
  
  // modify TTL associated  with the domain name (in seconds)
  // default is 60 seconds
  dnsServer.setTTL(300);
  // set which return code will be used for all other domains 
  // (e.g. sending ServerFailure instead of NonExistentDomain will reduce number of queries
  // sent by clients). Default is AsyncDNSReplyCode::NonExistentDomain
  dnsServer.setErrorReplyCode(AsyncDNSReplyCode::ServerFailure);

  // start DNS server for a specific domain name
  dnsServer.start(DNS_PORT, "*", Ethernet.localIP());

  ...
}

void loop() 
{
}

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Examples

1. AsyncCaptivePortal
2. AsyncCaptivePortalAdvanced
3. AsyncDNServerFull
4. AsyncDNSServer
5. multiFileProject

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Example AsyncDNSServer

1. File AsyncDNSServer.ino

AsyncDNSServer_RP2040W/examples/AsyncDNSServer/AsyncDNSServer.ino

Lines 10 to 119 in c9325a8

	#include "defines.h"
	#include <AsyncDNSServer_RP2040W.h>
	#include <AsyncWebServer_RP2040W.h>
	const byte DNS_PORT = 53;
	IPAddress apIP;
	AsyncDNSServer dnsServer;
	AsyncWebServer server(80);
	int status = WL_IDLE_STATUS;
	void handleNotFound(AsyncWebServerRequest *request)
	{
	String message = "Hello World from " + String(BOARD_NAME) + " using CYW43439 WiFi\n\n";
	message += "URI: ";
	message += request->url();
	request->send(200, "text/plain", message);
	}
	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()
	{
	Serial.begin(115200);
	while (!Serial && millis() < 5000);
	Serial.print("\nStart AsyncDNSServer on "); Serial.println(BOARD_NAME);
	Serial.println(ASYNC_DNS_SERVER_RP2040W_VERSION);
	#if defined(ASYNC_DNS_SERVER_RP2040W_VERSION_MIN)
	if (ASYNC_DNS_SERVER_RP2040W_VERSION_INT < ASYNC_DNS_SERVER_RP2040W_VERSION_MIN)
	{
	Serial.print("Warning. Must use this example on Version equal or later than : ");
	Serial.println(ASYNC_DNS_SERVER_RP2040W_VERSION_MIN_TARGET);
	}
	#endif
	///////////////////////////////////
	// 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();
	///////////////////////////////////
	// modify TTL associated with the domain name (in seconds)
	// default is 60 seconds
	dnsServer.setTTL(300);
	// set which return code will be used for all other domains
	// (e.g. sending ServerFailure instead of NonExistentDomain will reduce number of queries
	// sent by clients). Default is AsyncDNSReplyCode::NonExistentDomain
	dnsServer.setErrorReplyCode(AsyncDNSReplyCode::ServerFailure);
	// start DNS server for a specific domain name
	dnsServer.start(DNS_PORT, "*", apIP);
	server.onNotFound(handleNotFound);
	server.begin();
	Serial.print(F("HTTP EthernetWebServer is @ IP : "));
	Serial.println(apIP);
	}
	void loop()
	{
	}

2. File defines.h

AsyncDNSServer_RP2040W/examples/AsyncDNSServer/defines.h

Lines 1 to 29 in c9325a8

	/****************************************************************************************************************************
	defines.h
	AsyncDNSServer_RP2040W is an Async DNS_Server library for the RP2040W with CYW43439 WiFi
	Based on and modified from ESPAsyncDNSServer Library (https://github.com/devyte/ESPAsyncDNSServer)
	Built by Khoi Hoang https://github.com/khoih-prog/AsyncDNSServer_RP2040W
	*****************************************************************************************************************************/
	#ifndef defines_h
	#define defines_h
	#if !( defined(ARDUINO_RASPBERRY_PI_PICO_W) )
	#error For RASPBERRY_PI_PICO_W only
	#endif
	#define ASYNC_DNS_RP2040W_DEBUG_PORT Serial
	// Debug Level from 0 to 4
	#define _ASYNC_DNS_RP2040W_LOGLEVEL_ 4
	#if (_ASYNC_DNS_RP2040W_LOGLEVEL_ > 3)
	#warning Using RASPBERRY_PI_PICO_W with CYW43439 WiFi
	#endif
	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+
	#endif //defines_h

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Debug

Debug is enabled by default on Serial. To disable, use level 0

#define ASYNC_DNS_RP2040W_DEBUG_PORT      Serial

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_DNS_RP2040W_LOGLEVEL_      0

You can also change the debugging level from 0 to 4

#define ASYNC_DNS_RP2040W_DEBUG_PORT      Serial


// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_DNS_RP2040W_LOGLEVEL_    	4

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Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of the arduino-pico core

Sometimes, the library will only work if you update the arduino-pico core core to the latest version because I am using newly added functions.

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Issues

Submit issues to: AsyncDNSServer_RP2040W issues

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TO DO

1. Fix bug. Add enhancement

DONE

1. Add support to RASPBERRY_PI_PICO_W using CYW43439 WiFi
2. Add more examples.
3. Add debugging features
4. Add astyle using allman style. Restyle the library

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Contributions and Thanks

1. Based on and modified from Develo's ESPAsyncDNSServer Library.

⭐️ Develo

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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

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License

• The library is licensed under GPLv3

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Copyright

• Copyright (c) 2016- Develo
• Copyright (c) 2022- Khoi Hoang