UdpSendReceive_LAN8720.ino

/****************************************************************************************************************************
  UDPSendReceive_LAN8720.ino - Simple Arduino web server sample for ESP8266/ESP32 AT-command shield
  For STM32 with built-in Ethernet LAN8742A (Nucleo-144, DISCOVERY, etc) or W5x00/ENC28J60 shield/module

  EthernetWebServer_STM32 is a library for the STM32 running Ethernet WebServer

  Based on and modified from ESP8266 https://github.com/esp8266/Arduino/releases
  Built by Khoi Hoang https://github.com/khoih-prog/EthernetWebServer_STM32
  Licensed under MIT license
 *****************************************************************************************************************************/
/*
   Currently support
   1) STM32 boards with built-in LAN8742A Ethernet (to use USE_BUILTIN_ETHERNET = true) such as :
      - Nucleo-144 (F429ZI, F767ZI)
      - Discovery (STM32F746G-DISCOVERY)
      - STM32 boards (STM32F/L/H/G/WB/MP1) with 32K+ Flash, with Built-in Ethernet,
      - See How To Use Built-in Ethernet at (https://github.com/khoih-prog/EthernetWebServer_STM32/issues/1)
   2) STM32 boards with LAN8720 Ethernet (to use USE_BUILTIN_ETHERNET and USING_LAN8720 = true) such as :
      - BLACK_F407XX (BLACK_F407VE, BLACK_F407VG, BLACK_F407ZE, BLACK_F407ZG, BLACK_F407VE-mini), NUCLEO_F429ZI, DISCO_F746NG,
        NUCLEO_F7x6ZG
   3) STM32F/L/H/G/WB/MP1 boards (with 32+K Flash) running ENC28J60 shields (to use USE_BUILTIN_ETHERNET = false)
   4) STM32F/L/H/G/WB/MP1 boards (with 32+K Flash) running W5x00 shields
*/

#include "defines.h"

unsigned int localPort = 1883;    //10002;  // local port to listen on

char packetBuffer[255];          // buffer to hold incoming packet
char ReplyBuffer[] = "ACK";      // a string to send back

// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

void setup()
{
  Serial.begin(115200);

  delay(2000);

  Serial.println("\nStart UDPSendReceive_LAN8720 on " + String(BOARD_NAME) + ", using " + String(SHIELD_TYPE));
  Serial.println(ETHERNET_WEBSERVER_STM32_VERSION);

  // start the ethernet connection and the server:
  // Use DHCP dynamic IP and random mac
  uint16_t index = millis() % NUMBER_OF_MAC;
  // Use Static IP
  //Ethernet.begin(mac[index], ip);
  Ethernet.begin(mac[index]);

  // you're connected now, so print out the data
  Serial.print(F("You're connected to the network, IP = "));
  Serial.println(Ethernet.localIP());

  Serial.println(F("\nStarting connection to server..."));
  // if you get a connection, report back via serial:
  Udp.begin(localPort);

  Serial.print(F("Listening on port "));
  Serial.println(localPort);
}

void loop()
{
  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();

  if (packetSize)
  {
    Serial.print(F("Received packet of size "));
    Serial.println(packetSize);
    Serial.print(F("From "));
    IPAddress remoteIp = Udp.remoteIP();
    Serial.print(remoteIp);
    Serial.print(F(", port "));
    Serial.println(Udp.remotePort());

    // read the packet into packetBufffer
    int len = Udp.read(packetBuffer, 255);

    if (len > 0)
    {
      packetBuffer[len] = 0;
    }

    Serial.println(F("Contents:"));
    Serial.println(packetBuffer);

    // send a reply, to the IP address and port that sent us the packet we received
    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
    Udp.write(ReplyBuffer);
    Udp.endPacket();
  }
}