- Why do we need this AsyncUDP_ESP32_W5500 library
- Changelog
- Prerequisites
- Installation
- Libraries' Patches
- HOWTO Fix
Multiple DefinitionsLinker Error - HOWTO Use analogRead() with ESP32 running WiFi and/or BlueTooth (BT/BLE)
- HOWTO Setting up the Async UDP Client
- Examples
- Example AsyncUdpNTPClient
- Debug Terminal Output Samples
- Debug
- Troubleshooting
- Issues
- TO DO
- DONE
- Contributions and Thanks
- Contributing
- License
- Copyright
Why do we need this AsyncUDP_ESP32_W5500 library
This AsyncUDP_ESP32_W5500 library is a fully asynchronous UDP library, designed for a trouble-free, multi-connection network environment, for ESP32 boards using LwIP W5500 Ethernet. The library is easy to use and includes support for Unicast, Broadcast and Multicast environments.
This library is based on, modified from:
to apply the better and faster asynchronous feature of the powerful AsyncUDP into ESP32 boards using LwIP W5500 Ethernet.
- 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() the arrival of the UDP responding packets to process them.
- ESP32-based boards using
LwIPW5500 Ethernet
-
ESP32 Core 2.0.5+for ESP32-based boards. -
WebServer_ESP32_W5500 library 1.5.1+. To install, check
The suggested way to install is to:
The best way is to use Arduino Library Manager. Search for AsyncUDP_ESP32_W5500, then select / install the latest version. You can also use this link
- Navigate to AsyncUDP_ESP32_W5500 page.
- Download the latest release
AsyncUDP_ESP32_W5500-main.zip. - Extract the zip file to
AsyncUDP_ESP32_W5500-maindirectory - Copy the whole
AsyncUDP_ESP32_W5500-mainfolder to Arduino libraries' directory such as~/Arduino/libraries/.
- Install VS Code
- Install PlatformIO
- Install AsyncUDP_ESP32_W5500 library by using Library Manager. Search for AsyncUDP_ESP32_W5500 in Platform.io Author's Libraries
- 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
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:
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_W5500.hpp" //https://github.com/khoih-prog/AsyncUDP_ESP32_W5500in 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_W5500.h" //https://github.com/khoih-prog/AsyncUDP_ESP32_W5500Check the new multiFileProject example for a HOWTO demo.
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.
ADC1controlsADCfunction for pins GPIO32-GPIO39ADC2controlsADCfunction for pins GPIO0, 2, 4, 12-15, 25-27
Look in file adc_common.c
In ADC2, there're two locks used for different cases:
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.
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
ADC2for other functions, we have to acquire complicated firmware locks and very difficult to do - So, it's not advisable to use
ADC2with 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).
#if !( defined(ESP32) )
#error This code is designed for (ESP32 + W5500) to run on ESP32 platform! Please check your Tools->Board setting.
#endif
#include <Arduino.h>
#define ASYNC_UDP_ESP32_W5500_DEBUG_PORT Serial
// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_UDP_ESP32_W5500_LOGLEVEL_ 1
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 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 19
//#define MOSI_GPIO 23
//#define SCK_GPIO 18
//#define CS_GPIO 5
//////////////////////////////////////////////////////////
#include <AsyncUDP_ESP32_W5500.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 setup()
{
Serial.begin(115200);
while (!Serial && (millis() < 5000));
Serial.print(F("\nStart AsyncUDPSendReceive on "));
Serial.print(ARDUINO_BOARD);
Serial.print(F(" with "));
Serial.println(SHIELD_TYPE);
Serial.println(WEBSERVER_ESP32_W5500_VERSION);
Serial.println(ASYNC_UDP_ESP32_W5500_VERSION);
Serial.setDebugOutput(true);
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_W5500_onEvent();
// start the ethernet connection and the server:
// Use DHCP dynamic IP and random mac
uint16_t index = millis() % NUMBER_OF_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 *W5500_Mac = W5500_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[index] );
// 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_W5500_waitForConnect();
///////////////////////////////////
// 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);
}- AsyncUDPClient
- AsyncUdpNTPClient
- AsyncUdpSendReceive
- AsyncUDPServer
- AsyncUDPMulticastServer
- multiFileProject
Example AsyncUdpNTPClient
AsyncUDP_ESP32_W5500/examples/AsyncUdpNTPClient/AsyncUdpNTPClient.ino
Lines 11 to 246 in 65644f2
This is terminal debug output when running AsyncUdpNTPClient on ESP32_W5500 (ESP32 + W5500). It connects to NTP Server using AsyncUDP_ESP32_W5500 library, and requests NTP time every 60s. The packet is then received and processed asynchronously to print current UTC/GMT time.
Start AsyncUdpNTPClient on ESP32_DEV with ESP32_W5500
WebServer_ESP32_W5500 v1.5.1 for core v2.0.0+
AsyncUDP_ESP32_W5500 v2.0.0 for core v2.0.0+
ETH Started
ETH Connected
ETH MAC: DE:AD:BE:EF:FE:11, IPv4: 192.168.2.101
FULL_DUPLEX, 100Mbps
AsyncUdpNTPClient started @ IP address: 192.168.2.101
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.101:61672, Length: 48
Seconds since Jan 1 1900 = 3878826387
Epoch/Unix time = 1669837587
The UTC/GMT time is Wed 2022-11-30 19:46:27 GMTThis is terminal debug output when running AsyncUDPSendReceive on ESP32_W5500 (ESP32 + W5500). It connects to NTP Server 0.ca.pool.ntp.org (IP=208.81.1.244) using AsyncUDP_ESP32_W5500 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_W5500
WebServer_ESP32_W5500 v1.5.1 for core v2.0.0+
AsyncUDP_ESP32_W5500 v2.0.0 for core v2.0.0+
ETH Started
ETH Connected
ETH MAC: DE:AD:BE:EF:FE:11, IPv4: 192.168.2.101
FULL_DUPLEX, 100Mbps
AsyncUDPSendReceive started @ IP address: 192.168.2.101
Starting connection to server...
UDP connected
============= createNTPpacket =============
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.101:56800, Length: 48
Seconds since Jan 1 1900 = 3878826426
Epoch/Unix time = 1669837626
The UTC/GMT time is Wed 2022-11-30 19:47:06 GMT
============= sendACKPacket =============Debug is enabled by default on Serial. To disable, use level 0
#define ASYNC_UDP_ESP32_W5500_DEBUG_PORT Serial
// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_UDP_ESP32_W5500_LOGLEVEL_ 1You can also change the debugging level from 0 to 4
#define ASYNC_UDP_ESP32_W5500_DEBUG_PORT Serial
// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _ASYNC_UDP_ESP32_W5500_LOGLEVEL_ 4If you get compilation errors, more often than not, you may need to install a newer version of Arduino IDE, the Arduino STM32 core or depending libraries.
Sometimes, the library will only work if you update the STM32 core to the latest version because I am always using the latest cores /libraries.
Submit issues to: AsyncUDP_ESP32_W5500 issues
- Fix bug. Add enhancement
- Initial port to to ESP32_W5500 (ESP32 + W5500)
- Add more examples
- Add debugging features
- Fix bug in ESP32_W5500 examples to reduce connection time
- Fix
multiple-definitionslinker error - Add example multiFileProject to demo for multiple-file project
- Based on and modified from Hristo Gochkov's AsyncUDP. Many thanks to Hristo Gochkov for great AsyncUDP Library
 ⭐️⭐️ Hristo Gochkov |
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
- The library is licensed under GPLv3
Copyright (c) 2018- Hristo Gochkov
Copyright (c) 2022- Khoi Hoang