I am trying to become familiar with and understand sending and receiving UDP data over Ethernet and have installed the UIPEthernet library.
I have the UdpClient running on a Nano and the UdpServer on a Mega (with ENC28J60) using the Examples and communicating over a private network. (All I have changed is to assign addresses within my network address range).
The communications seems to be working EXCEPT that the "remote port number" reported by the server increases by 1 with each data group received. That doesn't seem right!
Client:
/*
* UIPEthernet UdpClient example.
*
* UIPEthernet is a TCP/IP stack that can be used with a enc28j60 based
* Ethernet-shield.
*
* UIPEthernet uses the fine uIP stack by Adam Dunkels <adam@sics.se>
*
* -----------------
*
* This UdpClient example tries to send a packet via udp to 192.168.0.1
* on port 5000 every 5 seconds. After successfully sending the packet it
* waits for up to 5 seconds for a response on the local port that has been
* implicitly opened when sending the packet.
*
* Copyright (C) 2013 by Norbert Truchsess (norbert.truchsess@t-online.de)
*/
#include <UIPEthernet.h>
EthernetUDP udp;
unsigned long next;
void setup() {
Serial.begin(9600);
uint8_t mac[6] = {0x00,0x06,0x02,0x03,0x04,0x05};
Ethernet.begin(mac,IPAddress(10,0,199,5));
next = millis()+5000;
}
void loop() {
int success;
int len = 0;
if (((signed long)(millis()-next))>0)
{
do
{
success = udp.beginPacket(IPAddress(10,0,199,6),5000);
Serial.print("beginPacket: ");
Serial.println(success ? "success" : "failed");
//beginPacket fails if remote ethaddr is unknown. In this case an
//arp-request is send out first and beginPacket succeeds as soon
//the arp-response is received.
}
while (!success && ((signed long)(millis()-next))<0);
if (!success )
goto stop;
success = udp.write("hello from Client");
Serial.print("bytes written: ");
Serial.println(success);
success = udp.endPacket();
Serial.print("endPacket: ");
Serial.println(success ? "success" : "failed");
do
{
//check for new udp-packet:
success = udp.parsePacket();
}
while (!success && ((signed long)(millis()-next))<0);
if (!success )
goto stop;
Serial.print("received: '");
do
{
int c = udp.read();
Serial.write(c);
len++;
}
while ((success = udp.available())>0);
Serial.print("', ");
Serial.print(len);
Serial.println(" bytes");
//finish reading this packet:
udp.flush();
stop:
udp.stop();
next = millis()+5000;
}
}
Server:
/*
* UIPEthernet UdpServer example.
*
* UIPEthernet is a TCP/IP stack that can be used with a enc28j60 based
* Ethernet-shield.
*
* UIPEthernet uses the fine uIP stack by Adam Dunkels <adam@sics.se>
*
* -----------------
*
* This UdpServer example sets up a udp-server at 192.168.0.6 on port 5000.
* send packet via upd to test
*
* Copyright (C) 2013 by Norbert Truchsess (norbert.truchsess@t-online.de)
*/
#include <UIPEthernet.h>
EthernetUDP udp;
void setup() {
Serial.begin(9600);
uint8_t mac[6] = {0x00,0x01,0x02,0x03,0x04,0x05};
Ethernet.begin(mac,IPAddress(10,0,199,6));
int success = udp.begin(5000);
Serial.print("initialize: ");
Serial.println(success ? "success" : "failed");
}
void loop() {
//check for new udp-packet:
int size = udp.parsePacket();
if (size > 0) {
do
{
char* msg = (char*)malloc(size+1);
int len = udp.read(msg,size+1);
msg[len]=0;
Serial.print("received: '");
Serial.print(msg);
free(msg);
}
while ((size = udp.available())>0);
//finish reading this packet:
udp.flush();
Serial.println("'");
int success;
do
{
Serial.print("remote ip: ");
Serial.println(udp.remoteIP());
Serial.print("remote port: ");
Serial.println(udp.remotePort());
//send new packet back to ip/port of client. This also
//configures the current connection to ignore packets from
//other clients!
success = udp.beginPacket(udp.remoteIP(),udp.remotePort());
Serial.print("beginPacket: ");
Serial.println(success ? "success" : "failed");
//beginPacket fails if remote ethaddr is unknown. In this case an
//arp-request is send out first and beginPacket succeeds as soon
//the arp-response is received.
}
while (!success);
success = udp.println("hello world from arduino");
Serial.print("bytes written: ");
Serial.println(success);
success = udp.endPacket();
Serial.print("endPacket: ");
Serial.println(success ? "success" : "failed");
udp.stop();
//restart with new connection to receive packets from other clients
Serial.print("restart connection: ");
Serial.println (udp.begin(5000) ? "success" : "failed");
}
}
Can anyone explain to me what is happening????