Send UDP from Arduino

Question

I'm struggling with the Transmission of the UDP packets. I'm using "Wireshark" as a control for incoming packets. The IP adress of the UDP packet is my fixed PC's configured IP right? I changed my script but I still don't receive any packages :/

Thanks!

Here's my code:

//Version 1.05

//necessary libraries
#include <SPI.h>
#include <Ethernet2.h>
#include <EthernetUdp2.h>

//Pin settings
#define CTD 19

//Network Settings
byte mac[] = { 0x90, 0xA2, 0xDA, 0x10, 0xEC, 0xAB };  //set MAC Address Ethernet Shield (Backside)
byte ip[]  = { XXX, XXX, X, X };                      //set IP-Address
byte gateway[] = { XXX, XXX, X, X };                  //set Gateway
byte subnet[]  = { 255, 255, 255, 0 };                //set Subnetmask


//local UDP port to listen on
unsigned int localPort = 5568;

//Recipient IP
IPAddress RecipientIP(XXX, XXX, X, X);

//Recipient UDP port
unsigned int RecipientPort = 8888;

//Buffer for sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];

//EthernetUDP instance
EthernetUDP Udp;

//CTD data
int incomingData = 0;


void setup()
{
   //Start Ethernet
  Ethernet.begin(mac, ip);

  //Start UDP
  Udp.begin(localPort);

  //for debug only
  Serial.begin(9600);

  //Serial baud rate for CTD
  Serial1.begin(1200);

  //Version 1.05
Serial.print("Version 1.05");

  //CTD
  pinMode(CTD, INPUT);
}

void loop()
{

//If CTD is sending
if (Serial1.available())
{
  //read incoming data
  incomingData = Serial1.read();

  //for debug only
  Serial.print("Data: ");
  Serial.println(incomingData, BIN);
}

//Send UDP packets
int packetSize = Udp.parsePacket();
  if (packetSize) 
  {

    //Debug only
    Serial.print("Packet");
    // read the packet into packetBufffer
    Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);

    // send to the IP address and port
    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
    Udp.write(incomingData);
    Udp.endPacket();
  }
}

You need some software on the other end to receive the packets — Peter Bruins
I'm using Wireshark to see if there are incoming packets and it doenst report any UDP from the Arduino's IP — TheTris
WireShark does not receive (or send) any date from/to the sender. You need a server script or piece of software that listens on certain port for the UDP packets. Check the UdpNTPClient example under Ethernet example projects in your Arduino IDE. — OpalApps
@OpalApps WireShark doesn't send anything but it most certainly does receive every IP packet that arrives at the host it is running on. That's what it's for. — user207421
@OP This code reads before it sends. Where is it reading from? and is anything being sent to it? — user207421

Xenon Xenon · Accepted Answer · 2020-03-16T23:10:12

Install Netcat. Then use the following syntax on your recipient computer: sudo nc -l 8888 Fire up the arduino, and you should see the output on your shell.

Send UDP from Arduino

1 Answers