README.md

AsyncUDP_ESP32_Ethernet

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Table of Contents

• Why do we need this AsyncUDP_ESP32_Ethernet library
  • Features
  • Why Async is better
  • Currently supported Boards
  • To-be supported Boards
• Changelog
• Prerequisites
• Installation
  • Use Arduino Library Manager
  • Manual Install
  • VS Code & PlatformIO
• Libraries' Patches
  • 1. For fixing ESP32 compile error
• HOWTO Fix Multiple Definitions Linker Error
• HOWTO Use analogRead() with ESP32 running WiFi and/or BlueTooth (BT/BLE)
  • 1. ESP32 has 2 ADCs, named ADC1 and ADC2
  • 2. ESP32 ADCs functions
  • 3. ESP32 WiFi uses ADC2 for WiFi functions
• HOWTO Setting up the Async UDP Client
• How to connect W5500, W6100 or ENC28J60 to ESP32
• Examples
  • 1. AsyncUDPClient
  • 2. AsyncUdpNTPClient
  • 3. AsyncUdpSendReceive
  • 4. AsyncUDPServer
  • 5. AsyncUDPMulticastServer
  • 6. multiFileProject New
• Example AsyncUdpNTPClient
  • File AsyncUdpNTPClient.ino
• Debug Terminal Output Samples
  • 1. AsyncUdpNTPClient on ESP32_DEV with ESP32_W6100
  • 2. AsyncUDPSendReceive on ESP32_DEV with ESP32_W6100
  • 3. AsyncUdpNTPClient on ESP32_DEV with ESP32_W5500
  • 4. AsyncUDPSendReceive on ESP32_DEV with ESP32_ENC28J60
• Troubleshooting
• Issues
• TO DO
• DONE
• Contributions and Thanks
• Contributing
• License
• Copyright

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Why do we need this AsyncUDP_ESP32_Ethernet library

Features

This AsyncUDP_ESP32_Ethernet library is a fully asynchronous UDP library, designed for a trouble-free, multi-connection network environment, for ESP32 boards using LwIP W5500, W6100 or ENC28J60 Ethernet. The library is easy to use and includes support for Unicast, Broadcast and Multicast environments.

This library is based on, modified from:

1. Hristo Gochkov's AsyncUDP

to apply the better and faster asynchronous feature of the powerful AsyncUDP into ESP32 boards using LwIP W5500, W6100 or ENC28J60 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
• After connecting to a UDP server as an Async Client, you are immediately ready to handle other connections while the Client is taking care of receiving the UDP responding packets in the background.
• You are not required to check in a tight loop() for the arrival of the UDP responding packets to process them.

Currently supported Boards

1. ESP32-based boards using LwIP W5500, W6100 or ENC28J60 Ethernet

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W5500

FULL_DUPLEX, 100Mbps

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W6100

FULL_DUPLEX, 100Mbps

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ENC28J60

FULL_DUPLEX, 10Mbps

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To-be Supported Boards

1. New ESP32 using LwIP W5500, W6100 or ENC28J60 Ethernet

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Prerequisites

1. Arduino IDE 1.8.19+ for Arduino
2. ESP32 Core 2.0.6+ for ESP32-based boards.
3. WebServer_ESP32_W5500 library 1.5.2+. To install, check
4. WebServer_ESP32_W6100 library 1.5.2+. To install, check
5. WebServer_ESP32_ENC library 1.5.1+. 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 AsyncUDP_ESP32_Ethernet, then select / install the latest version. You can also use this link for more detailed instructions.

Manual Install

1. Navigate to AsyncUDP_ESP32_Ethernet page.
2. Download the latest release AsyncUDP_ESP32_Ethernet-main.zip.
3. Extract the zip file to AsyncUDP_ESP32_Ethernet-main directory
4. Copy the whole AsyncUDP_ESP32_Ethernet-main folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO:

1. Install VS Code
2. Install PlatformIO
3. Install AsyncUDP_ESP32_Ethernet library by using Library Manager. Search for AsyncUDP_ESP32_Ethernet 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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Libraries' Patches

1. For fixing ESP32 compile error

To fix ESP32 compile error, just copy the following file into the ESP32 cores/esp32 directory (e.g. ./arduino-1.8.19/hardware/espressif/cores/esp32) to overwrite the old file:

• Server.h

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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 "AsyncUDP_ESP32_Ethernet.hpp"     //https://github.com/khoih-prog/AsyncUDP_ESP32_Ethernet

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 "AsyncUDP_ESP32_Ethernet.h"       //https://github.com/khoih-prog/AsyncUDP_ESP32_Ethernet

Check the new multiFileProject example for a HOWTO demo.

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HOWTO Use analogRead() with ESP32 running WiFi and/or BlueTooth (BT/BLE)

Please have a look at ESP_WiFiManager Issue 39: Not able to read analog port when using the autoconnect example to have more detailed description and solution of the issue.

1. ESP32 has 2 ADCs, named ADC1 and ADC2

2. ESP32 ADCs functions

• ADC1 controls ADC function for pins GPIO32-GPIO39
• ADC2 controls ADC function for pins GPIO0, 2, 4, 12-15, 25-27

3.. ESP32 WiFi uses ADC2 for WiFi functions

Look in file adc_common.c

In ADC2, there're two locks used for different cases:

1. lock shared with app and Wi-Fi: ESP32: When Wi-Fi using the ADC2, we assume it will never stop, so app checks the lock and returns immediately if failed. ESP32S2: The controller's control over the ADC is determined by the arbiter. There is no need to control by lock.

2. lock shared between tasks: when several tasks sharing the ADC2, we want to guarantee all the requests will be handled. Since conversions are short (about 31us), app returns the lock very soon, we use a spinlock to stand there waiting to do conversions one by one.

adc2_spinlock should be acquired first, then adc2_wifi_lock or rtc_spinlock.

• In order to use ADC2 for other functions, we have to acquire complicated firmware locks and very difficult to do
• So, it's not advisable to use ADC2 with WiFi/BlueTooth (BT/BLE).
• Use ADC1, and pins GPIO32-GPIO39
• If somehow it's a must to use those pins serviced by ADC2 (GPIO0, 2, 4, 12, 13, 14, 15, 25, 26 and 27), use the fix mentioned at the end of ESP_WiFiManager Issue 39: Not able to read analog port when using the autoconnect example to work with ESP32 WiFi/BlueTooth (BT/BLE).

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HOWTO Setting up the Async UDP Client

AsyncUDP_ESP32_Ethernet/examples/AsyncUdpSendReceive/AsyncUdpSendReceive.ino

Lines 11 to 376 in c63051f

	#if !( defined(ESP32) )
	#error This code is designed for (ESP32 + LwIP W5500, W6100 or ENC28J60) to run on ESP32 platform! Please check your Tools->Board setting.
	#endif
	#include <Arduino.h>
	#define USING_W5500 false
	#define USING_W6100 true
	#define USING_ENC28J60 false
	#if !USING_W5500 && !USING_W6100 && !USING_ENC28J60
	#undef USING_W5500
	#define USING_W5500 true
	#endif
	#define ASYNC_UDP_ESP32_ETHERNET_DEBUG_PORT Serial
	// Use from 0 to 4. Higher number, more debugging messages and memory usage.
	#define _ASYNC_UDP_ESP32_ETHERNET_LOGLEVEL_ 2
	//////////////////////////////////////////////////////////
	#if USING_W5500
	#define ESP32_Ethernet_onEvent ESP32_W5500_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_W5500_waitForConnect
	// For ESP32_S3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI3_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	// For ESP32_C3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 10
	//#define MISO_GPIO 5
	//#define MOSI_GPIO 6
	//#define SCK_GPIO 4
	//#define CS_GPIO 7
	//////////////////////////////////////////////////////////
	#elif USING_W6100
	#define ESP32_Ethernet_onEvent ESP32_W6100_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_W6100_waitForConnect
	// For ESP32_S3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI3_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	// For ESP32_C3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 10
	//#define MISO_GPIO 5
	//#define MOSI_GPIO 6
	//#define SCK_GPIO 4
	//#define CS_GPIO 7
	//////////////////////////////////////////////////////////
	#else // #if USING_W5500
	//////////////////////////////////////////////////////////
	// For ENC28J60
	#define ESP32_Ethernet_onEvent ESP32_ENC_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_ENC_waitForConnect
	#define ETH_SPI_HOST SPI_HOST
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 8
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	//////////////////////////////////////////////////////////
	#endif // #if USING_W5500
	//////////////////////////////////////////////////////////
	#include <AsyncUDP_ESP32_Ethernet.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, 0xFE, 0x01 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x02 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x03 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x04 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x05 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x06 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x07 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x08 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x09 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0A },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0B },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0C },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0D },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0E },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0F },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x10 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x11 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x12 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x13 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x14 },
	};
	// Select the IP address according to your local network
	IPAddress myIP(192, 168, 2, 232);
	IPAddress myGW(192, 168, 2, 1);
	IPAddress mySN(255, 255, 255, 0);
	// Google DNS Server IP
	IPAddress myDNS(8, 8, 8, 8);
	/////////////////////////////////////////////
	#include <time.h>
	// 0.ca.pool.ntp.org
	IPAddress timeServerIP = IPAddress(208, 81, 1, 244);
	// time.nist.gov
	//IPAddress timeServerIP = IPAddress(132, 163, 96, 1);
	#define NTP_REQUEST_PORT 123
	char ReplyBuffer[] = "ACK"; // a string to send back
	char timeServer[] = "time.nist.gov"; // NTP server
	const int NTP_PACKET_SIZE = 48; // NTP timestamp is in the first 48 bytes of the message
	byte packetBuffer[NTP_PACKET_SIZE]; // buffer to hold incoming and outgoing packets
	// A UDP instance to let us send and receive packets over UDP
	AsyncUDP Udp;
	void sendACKPacket(void)
	{
	Serial.println("============= sendACKPacket =============");
	// Send unicast ACK to the same remoteIP and remotePort we received the packet
	// The AsyncUDP_STM32 library will take care of the correct IP and port based on pcb
	Udp.write((uint8_t *) ReplyBuffer, sizeof(ReplyBuffer));
	}
	// send an NTP request to the time server at the given address
	void createNTPpacket(void)
	{
	Serial.println("============= createNTPpacket =============");
	// set all bytes in the buffer to 0
	memset(packetBuffer, 0, NTP_PACKET_SIZE);
	// Initialize values needed to form NTP request
	// (see URL above for details on the packets)
	packetBuffer[0] = 0b11100011; // LI, Version, Mode
	packetBuffer[1] = 0; // Stratum, or type of clock
	packetBuffer[2] = 6; // Polling Interval
	packetBuffer[3] = 0xEC; // Peer Clock Precision
	// 8 bytes of zero for Root Delay & Root Dispersion
	packetBuffer[12] = 49;
	packetBuffer[13] = 0x4E;
	packetBuffer[14] = 49;
	packetBuffer[15] = 52;
	}
	void sendNTPPacket(void)
	{
	createNTPpacket();
	//Send unicast
	Udp.write(packetBuffer, sizeof(packetBuffer));
	}
	void parsePacket(AsyncUDPPacket packet)
	{
	struct tm ts;
	char buf[80];
	memcpy(packetBuffer, packet.data(), sizeof(packetBuffer));
	Serial.print("Received UDP Packet Type: ");
	Serial.println(packet.isBroadcast() ? "Broadcast" : packet.isMulticast() ? "Multicast" : "Unicast");
	Serial.print("From: ");
	Serial.print(packet.remoteIP());
	Serial.print(":");
	Serial.print(packet.remotePort());
	Serial.print(", To: ");
	Serial.print(packet.localIP());
	Serial.print(":");
	Serial.print(packet.localPort());
	Serial.print(", Length: ");
	Serial.print(packet.length());
	Serial.println();
	unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
	unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
	// combine the four bytes (two words) into a long integer
	// this is NTP time (seconds since Jan 1 1900):
	unsigned long secsSince1900 = highWord << 16 | lowWord;
	Serial.print(F("Seconds since Jan 1 1900 = "));
	Serial.println(secsSince1900);
	// now convert NTP time into )everyday time:
	Serial.print(F("Epoch/Unix time = "));
	// Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
	const unsigned long seventyYears = 2208988800UL;
	// subtract seventy years:
	unsigned long epoch = secsSince1900 - seventyYears;
	time_t epoch_t = epoch; //secsSince1900 - seventyYears;
	// print Unix time:
	Serial.println(epoch);
	// print the hour, minute and second:
	Serial.print(F("The UTC/GMT time is ")); // UTC is the time at Greenwich Meridian (GMT)
	ts = *localtime(&epoch_t);
	strftime(buf, sizeof(buf), "%a %Y-%m-%d %H:%M:%S %Z", &ts);
	Serial.println(buf);
	// send a reply, to the IP address and port that sent us the packet we received
	sendACKPacket();
	}
	void initEthernet()
	{
	UDP_LOGWARN(F("Default SPI pinout:"));
	UDP_LOGWARN1(F("SPI_HOST:"), ETH_SPI_HOST);
	UDP_LOGWARN1(F("MOSI:"), MOSI_GPIO);
	UDP_LOGWARN1(F("MISO:"), MISO_GPIO);
	UDP_LOGWARN1(F("SCK:"), SCK_GPIO);
	UDP_LOGWARN1(F("CS:"), CS_GPIO);
	UDP_LOGWARN1(F("INT:"), INT_GPIO);
	UDP_LOGWARN1(F("SPI Clock (MHz):"), SPI_CLOCK_MHZ);
	UDP_LOGWARN(F("========================="));
	///////////////////////////////////
	// To be called before ETH.begin()
	ESP32_Ethernet_onEvent();
	// start the ethernet connection and the server:
	// Use DHCP dynamic IP and random mac
	//bool begin(int MISO_GPIO, int MOSI_GPIO, int SCLK_GPIO, int CS_GPIO, int INT_GPIO, int SPI_CLOCK_MHZ,
	// int SPI_HOST, uint8_t *W6100_Mac = W6100_Default_Mac);
	ETH.begin( MISO_GPIO, MOSI_GPIO, SCK_GPIO, CS_GPIO, INT_GPIO, SPI_CLOCK_MHZ, ETH_SPI_HOST );
	//ETH.begin( MISO_GPIO, MOSI_GPIO, SCK_GPIO, CS_GPIO, INT_GPIO, SPI_CLOCK_MHZ, ETH_SPI_HOST, mac[millis() % NUMBER_OF_MAC] );
	// Static IP, leave without this line to get IP via DHCP
	//bool config(IPAddress local_ip, IPAddress gateway, IPAddress subnet, IPAddress dns1 = 0, IPAddress dns2 = 0);
	//ETH.config(myIP, myGW, mySN, myDNS);
	ESP32_Ethernet_waitForConnect();
	///////////////////////////////////
	}
	////////////////////////////////////
	void setup()
	{
	Serial.begin(115200);
	while (!Serial && (millis() < 5000));
	delay(500);
	Serial.print(F("\nStart AsyncUDPSendReceive on "));
	Serial.print(ARDUINO_BOARD);
	Serial.print(F(" with "));
	Serial.println(SHIELD_TYPE);
	#if USING_W5500
	Serial.println(WEBSERVER_ESP32_W5500_VERSION);
	#elif USING_W6100
	Serial.println(WEBSERVER_ESP32_W6100_VERSION);
	#else
	Serial.println(WEBSERVER_ESP32_ENC_VERSION);
	#endif
	Serial.println(ASYNC_UDP_ESP32_ETHERNET_VERSION);
	Serial.setDebugOutput(true);
	///////////////////////////////////
	initEthernet();
	///////////////////////////////////
	// Client address
	Serial.print("AsyncUDPSendReceive started @ IP address: ");
	Serial.println(ETH.localIP());
	Serial.println(F("\nStarting connection to server..."));
	//NTP requests are to port NTP_REQUEST_PORT = 123
	if (Udp.connect(timeServerIP, NTP_REQUEST_PORT))
	{
	Serial.println("UDP connected");
	Udp.onPacket([](AsyncUDPPacket packet)
	{
	parsePacket(packet);
	});
	}
	}
	void loop()
	{
	sendNTPPacket();
	// wait 60 seconds before asking for the time again
	delay(60000);
	}

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How to connect W5500, W6100 or ENC28J60 to ESP32

You can change the INT pin to another one. Default is GPIO4

// Must connect INT to GPIOxx or not working
#define INT_GPIO            4

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W6100

FULL_DUPLEX, 100Mbps

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W5500

FULL_DUPLEX, 100Mbps

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ENC28J60

FULL_DUPLEX, 10Mbps

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W5500, W6100 or ENC28J60	<--->	ESP32
MOSI	<--->	GPIO23
MISO	<--->	GPIO19
SCK	<--->	GPIO18
CS/SS	<--->	GPIO5
INT	<--->	GPIO4
RST	<--->	RST
GND	<--->	GND
3.3V	<--->	3.3V

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Examples

1. AsyncUDPClient
2. AsyncUdpNTPClient
3. AsyncUdpSendReceive
4. AsyncUDPServer
5. AsyncUDPMulticastServer
6. multiFileProject

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Example AsyncUdpNTPClient

File AsyncUdpNTPClient.ino

AsyncUDP_ESP32_Ethernet/examples/AsyncUdpNTPClient/AsyncUdpNTPClient.ino

Lines 11 to 358 in c63051f

	#if !( defined(ESP32) )
	#error This code is designed for (ESP32 + LwIP W5500, W6100 or ENC28J60) to run on ESP32 platform! Please check your Tools->Board setting.
	#endif
	#include <Arduino.h>
	#define USING_W5500 false
	#define USING_W6100 true
	#define USING_ENC28J60 false
	#if !USING_W5500 && !USING_W6100 && !USING_ENC28J60
	#undef USING_W5500
	#define USING_W5500 true
	#endif
	#define ASYNC_UDP_ESP32_ETHERNET_DEBUG_PORT Serial
	// Use from 0 to 4. Higher number, more debugging messages and memory usage.
	#define _ASYNC_UDP_ESP32_ETHERNET_LOGLEVEL_ 2
	//////////////////////////////////////////////////////////
	#if USING_W5500
	#define ESP32_Ethernet_onEvent ESP32_W5500_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_W5500_waitForConnect
	// For ESP32_S3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI3_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	// For ESP32_C3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 10
	//#define MISO_GPIO 5
	//#define MOSI_GPIO 6
	//#define SCK_GPIO 4
	//#define CS_GPIO 7
	//////////////////////////////////////////////////////////
	#elif USING_W6100
	#define ESP32_Ethernet_onEvent ESP32_W6100_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_W6100_waitForConnect
	// For ESP32_S3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI3_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	// For ESP32_C3
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define ETH_SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 25
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 10
	//#define MISO_GPIO 5
	//#define MOSI_GPIO 6
	//#define SCK_GPIO 4
	//#define CS_GPIO 7
	//////////////////////////////////////////////////////////
	#else // #if USING_W5500
	//////////////////////////////////////////////////////////
	// For ENC28J60
	#define ESP32_Ethernet_onEvent ESP32_ENC_onEvent
	#define ESP32_Ethernet_waitForConnect ESP32_ENC_waitForConnect
	#define ETH_SPI_HOST SPI_HOST
	// Optional values to override default settings
	// Don't change unless you know what you're doing
	//#define SPI_HOST SPI2_HOST
	//#define SPI_CLOCK_MHZ 8
	// Must connect INT to GPIOxx or not working
	//#define INT_GPIO 4
	//#define MISO_GPIO 13
	//#define MOSI_GPIO 11
	//#define SCK_GPIO 12
	//#define CS_GPIO 10
	//////////////////////////////////////////////////////////
	#endif // #if USING_W5500
	//////////////////////////////////////////////////////////
	#include <AsyncUDP_ESP32_Ethernet.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, 0xFE, 0x01 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x02 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x03 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x04 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x05 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x06 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x07 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x08 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x09 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0A },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0B },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0C },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0D },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x0E },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x0F },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x10 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x11 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x12 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0x13 },
	{ 0xDE, 0xAD, 0xBE, 0xEF, 0xBE, 0x14 },
	};
	// Select the IP address according to your local network
	IPAddress myIP(192, 168, 2, 232);
	IPAddress myGW(192, 168, 2, 1);
	IPAddress mySN(255, 255, 255, 0);
	// Google DNS Server IP
	IPAddress myDNS(8, 8, 8, 8);
	/////////////////////////////////////////////
	#include <time.h>
	// 0.ca.pool.ntp.org
	IPAddress timeServerIP = IPAddress(208, 81, 1, 244);
	// time.nist.gov
	//IPAddress timeServerIP = IPAddress(132, 163, 96, 1);
	#define NTP_REQUEST_PORT 123
	const int NTP_PACKET_SIZE = 48; // NTP timestamp is in the first 48 bytes of the message
	byte packetBuffer[NTP_PACKET_SIZE]; // buffer to hold incoming and outgoing packets
	// A UDP instance to let us send and receive packets over UDP
	AsyncUDP Udp;
	// send an NTP request to the time server at the given address
	void createNTPpacket(void)
	{
	Serial.println("============= createNTPpacket =============");
	// set all bytes in the buffer to 0
	memset(packetBuffer, 0, NTP_PACKET_SIZE);
	// Initialize values needed to form NTP request
	// (see URL above for details on the packets)
	packetBuffer[0] = 0b11100011; // LI, Version, Mode
	packetBuffer[1] = 0; // Stratum, or type of clock
	packetBuffer[2] = 6; // Polling Interval
	packetBuffer[3] = 0xEC; // Peer Clock Precision
	// 8 bytes of zero for Root Delay & Root Dispersion
	packetBuffer[12] = 49;
	packetBuffer[13] = 0x4E;
	packetBuffer[14] = 49;
	packetBuffer[15] = 52;
	}
	void parsePacket(AsyncUDPPacket packet)
	{
	struct tm ts;
	char buf[80];
	memcpy(packetBuffer, packet.data(), sizeof(packetBuffer));
	Serial.print("Received UDP Packet Type: ");
	Serial.println(packet.isBroadcast() ? "Broadcast" : packet.isMulticast() ? "Multicast" : "Unicast");
	Serial.print("From: ");
	Serial.print(packet.remoteIP());
	Serial.print(":");
	Serial.print(packet.remotePort());
	Serial.print(", To: ");
	Serial.print(packet.localIP());
	Serial.print(":");
	Serial.print(packet.localPort());
	Serial.print(", Length: ");
	Serial.print(packet.length());
	Serial.println();
	unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
	unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
	// combine the four bytes (two words) into a long integer
	// this is NTP time (seconds since Jan 1 1900):
	unsigned long secsSince1900 = highWord << 16 | lowWord;
	Serial.print(F("Seconds since Jan 1 1900 = "));
	Serial.println(secsSince1900);
	// now convert NTP time into )everyday time:
	Serial.print(F("Epoch/Unix time = "));
	// Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
	const unsigned long seventyYears = 2208988800UL;
	// subtract seventy years:
	unsigned long epoch = secsSince1900 - seventyYears;
	time_t epoch_t = epoch; //secsSince1900 - seventyYears;
	// print Unix time:
	Serial.println(epoch);
	// print the hour, minute and second:
	Serial.print(F("The UTC/GMT time is ")); // UTC is the time at Greenwich Meridian (GMT)
	ts = *localtime(&epoch_t);
	strftime(buf, sizeof(buf), "%a %Y-%m-%d %H:%M:%S %Z", &ts);
	Serial.println(buf);
	}
	void sendNTPPacket(void)
	{
	createNTPpacket();
	//Send unicast
	Udp.write(packetBuffer, sizeof(packetBuffer));
	}
	void initEthernet()
	{
	UDP_LOGWARN(F("Default SPI pinout:"));
	UDP_LOGWARN1(F("SPI_HOST:"), ETH_SPI_HOST);
	UDP_LOGWARN1(F("MOSI:"), MOSI_GPIO);
	UDP_LOGWARN1(F("MISO:"), MISO_GPIO);
	UDP_LOGWARN1(F("SCK:"), SCK_GPIO);
	UDP_LOGWARN1(F("CS:"), CS_GPIO);
	UDP_LOGWARN1(F("INT:"), INT_GPIO);
	UDP_LOGWARN1(F("SPI Clock (MHz):"), SPI_CLOCK_MHZ);
	UDP_LOGWARN(F("========================="));
	///////////////////////////////////
	// To be called before ETH.begin()
	ESP32_Ethernet_onEvent();
	// start the ethernet connection and the server:
	// Use DHCP dynamic IP and random mac
	//bool begin(int MISO_GPIO, int MOSI_GPIO, int SCLK_GPIO, int CS_GPIO, int INT_GPIO, int SPI_CLOCK_MHZ,
	// int SPI_HOST, uint8_t *W6100_Mac = W6100_Default_Mac);
	ETH.begin( MISO_GPIO, MOSI_GPIO, SCK_GPIO, CS_GPIO, INT_GPIO, SPI_CLOCK_MHZ, ETH_SPI_HOST );
	//ETH.begin( MISO_GPIO, MOSI_GPIO, SCK_GPIO, CS_GPIO, INT_GPIO, SPI_CLOCK_MHZ, ETH_SPI_HOST, mac[millis() % NUMBER_OF_MAC] );
	// Static IP, leave without this line to get IP via DHCP
	//bool config(IPAddress local_ip, IPAddress gateway, IPAddress subnet, IPAddress dns1 = 0, IPAddress dns2 = 0);
	//ETH.config(myIP, myGW, mySN, myDNS);
	ESP32_Ethernet_waitForConnect();
	///////////////////////////////////
	}
	////////////////////////////////////
	void setup()
	{
	Serial.begin(115200);
	while (!Serial && (millis() < 5000));
	delay(500);
	Serial.print(F("\nStart AsyncUdpNTPClient on "));
	Serial.print(ARDUINO_BOARD);
	Serial.print(F(" with "));
	Serial.println(SHIELD_TYPE);
	#if USING_W5500
	Serial.println(WEBSERVER_ESP32_W5500_VERSION);
	#elif USING_W6100
	Serial.println(WEBSERVER_ESP32_W6100_VERSION);
	#else
	Serial.println(WEBSERVER_ESP32_ENC_VERSION);
	#endif
	Serial.println(ASYNC_UDP_ESP32_ETHERNET_VERSION);
	Serial.setDebugOutput(true);
	///////////////////////////////////
	initEthernet();
	///////////////////////////////////
	// Client address
	Serial.print("AsyncUdpNTPClient started @ IP address: ");
	Serial.println(ETH.localIP());
	//NTP requests are to port NTP_REQUEST_PORT = 123
	if (Udp.connect(timeServerIP, NTP_REQUEST_PORT))
	{
	Serial.println("UDP connected");
	Udp.onPacket([](AsyncUDPPacket packet)
	{
	parsePacket(packet);
	});
	}
	}
	void loop()
	{
	sendNTPPacket();
	// wait 60 seconds before asking for the time again
	delay(60000);
	}

---

Debug Terminal Output Samples

1. AsyncUdpNTPClient on ESP32_DEV with ESP32_W6100

This is terminal debug output when running AsyncUdpNTPClient on ESP32_W6100 (ESP32_DEV + W6100). It connects to It connects to NTP Server 0.ca.pool.ntp.org (IP=208.81.1.244), using AsyncUDP_ESP32_Ethernet library, and requests NTP time every 60s. The packet is then received and processed asynchronously to print current UTC/GMT time.

Connect to NTP server 0.ca.pool.ntp.org (IP=208.81.1.244)

Start AsyncUdpNTPClient on ESP32_DEV with ESP32_W6100
WebServer_ESP32_W6100 v1.5.2 for core v2.0.0+
AsyncUDP_ESP32_Ethernet v2.1.0 for core v2.0.0+
[UDP] Default SPI pinout:
[UDP] SPI_HOST: 2
[UDP] MOSI: 23
[UDP] MISO: 19
[UDP] SCK: 18
[UDP] CS: 5
[UDP] INT: 4
[UDP] SPI Clock (MHz): 25
[UDP] =========================

ETH Started
ETH Connected
ETH MAC: 0C:B8:15:D8:01:D7, IPv4: 192.168.2.34
FULL_DUPLEX, 100Mbps
AsyncUdpNTPClient started @ IP address: 192.168.2.34
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.34:55314, Length: 48
Seconds since Jan 1 1900 = 3882392659
Epoch/Unix time = 1673403859
The UTC/GMT time is Wed 2023-01-11 02:24:19 GMT

---

2. AsyncUDPSendReceive on ESP32_DEV with ESP32_W6100

This is terminal debug output when running AsyncUDPSendReceive on ESP32_W6100 (ESP32_DEV + W6100). It connects to NTP Server 0.ca.pool.ntp.org (IP=208.81.1.244) using AsyncUDP_ESP32_Ethernet library, and requests NTP time every 60s. The packet is received and processed asynchronously to print current UTC/GMT time. The ACK packet is then sent to give acknowledge to the NTP server

Start AsyncUDPSendReceive on ESP32_DEV with ESP32_W6100
WebServer_ESP32_W6100 v1.5.2 for core v2.0.0+
AsyncUDP_ESP32_Ethernet v2.1.0 for core v2.0.0+
[UDP] Default SPI pinout:
[UDP] SPI_HOST: 2
[UDP] MOSI: 23
[UDP] MISO: 19
[UDP] SCK: 18
[UDP] CS: 5
[UDP] INT: 4
[UDP] SPI Clock (MHz): 25
[UDP] =========================

ETH Started
ETH Connected
ETH MAC: 0C:B8:15:D8:01:D7, IPv4: 192.168.2.34
FULL_DUPLEX, 100Mbps
AsyncUDPSendReceive started @ IP address: 192.168.2.34

Starting connection to server...
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.34:62164, Length: 48
Seconds since Jan 1 1900 = 3882392738
Epoch/Unix time = 1673403938
The UTC/GMT time is Wed 2023-01-11 02:25:38 GMT
============= sendACKPacket =============
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.34:62164, Length: 48
Seconds since Jan 1 1900 = 3882392797
Epoch/Unix time = 1673403997
The UTC/GMT time is Wed 2023-01-11 02:26:37 GMT
============= sendACKPacket =============

---

3. AsyncUdpNTPClient on ESP32_DEV with ESP32_W5500

This is terminal debug output when running AsyncUdpNTPClient on ESP32_W5500 (ESP32_DEV + W5500). It connects to NTP Server using AsyncUDP_ESP32_Ethernet library, and requests NTP time every 60s. The packet is then received and processed asynchronously to print current UTC/GMT time.

Connect to NTP server 0.ca.pool.ntp.org (IP=208.81.1.244)

Start AsyncUdpNTPClient on ESP32_DEV with ESP32_W5500
WebServer_ESP32_W5500 v1.5.2 for core v2.0.0+
AsyncUDP_ESP32_Ethernet v2.1.0 for core v2.0.0+
[UDP] Default SPI pinout:
[UDP] SPI_HOST: 2
[UDP] MOSI: 23
[UDP] MISO: 19
[UDP] SCK: 18
[UDP] CS: 5
[UDP] INT: 4
[UDP] SPI Clock (MHz): 25
[UDP] =========================

ETH Started
ETH Connected
ETH MAC: 0C:B8:15:D8:01:D7, IPv4: 192.168.2.34
FULL_DUPLEX, 100Mbps
AsyncUDPSendReceive started @ IP address: 192.168.2.34
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.34:62164, Length: 48
Seconds since Jan 1 1900 = 3882392857
Epoch/Unix time = 1673404057
The UTC/GMT time is Wed 2023-01-11 02:27:37 GMT

---

4. AsyncUDPSendReceive on ESP32_DEV with ESP32_ENC28J60

This is terminal debug output when running AsyncUDPSendReceive on ESP32_ENC28J60 (ESP32_DEV + ENC28J60). It connects to NTP Server 0.ca.pool.ntp.org (IP=208.81.1.244) using AsyncUDP_ESP32_Ethernet library, and requests NTP time every 60s. The packet is received and processed asynchronously to print current UTC/GMT time. The ACK packet is then sent to give acknowledge to the NTP server

Start AsyncUDPSendReceive on ESP32_DEV with ESP32_ENC28J60
WebServer_ESP32_ENC v1.5.1 for core v2.0.0+
AsyncUDP_ESP32_Ethernet v2.1.0 for core v2.0.0+
[UDP] Default SPI pinout:
[UDP] SPI_HOST: 2
[UDP] MOSI: 23
[UDP] MISO: 19
[UDP] SCK: 18
[UDP] CS: 5
[UDP] INT: 4
[UDP] SPI Clock (MHz): 25
[UDP] =========================

ETH Started
ETH Connected
ETH MAC: 0C:B8:15:D8:01:D7, IPv4: 192.168.2.34
FULL_DUPLEX, 10Mbps
AsyncUDPSendReceive started @ IP address: 192.168.2.34

Starting connection to server...
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.34:62164, Length: 48
Seconds since Jan 1 1900 = 3882392797
Epoch/Unix time = 1673403997
The UTC/GMT time is Wed 2023-01-11 02:26:37 GMT
============= sendACKPacket =============

---

---

Debug

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

#define ASYNC_UDP_ESP32_ETHERNET_DEBUG_PORT      Serial

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_UDP_ESP32_ETHERNET_LOGLEVEL_      1

You can also change the debugging level from 0 to 4

#define ASYNC_UDP_ESP32_ETHERNET_DEBUG_PORT      Serial

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_UDP_ESP32_ETHERNET_LOGLEVEL_      4

---

---

Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of Arduino IDE, the Arduino ESP32 core or depending libraries.

Sometimes, the library will only work if you update the ESP32 core to the latest version because I am always using the latest cores /libraries.

---

---

Issues

Submit issues to: AsyncUDP_ESP32_Ethernet issues

---

---

TO DO

1. Fix bug. Add enhancement
2. Add support to more LwIP Ethernet shields, such as W5100, W5100S, etc.

---

DONE

1. Initial port to ESP32-based boards using LwIP W5500, W6100 or ENC28J60 Ethernet
2. Use allman astyle and add utils. Restyle the library

---

---

Contributions and Thanks

1. Based on and modified from Hristo Gochkov's AsyncUDP. Many thanks to Hristo Gochkov for great AsyncUDP Library

⭐️⭐️ Hristo Gochkov

---

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 GPLv3

---

Copyright

Copyright (c) 2018- Hristo Gochkov

Copyright (c) 2023- Khoi Hoang