WiFi Shield UDP packets not sending

Using Arduino Programming Questions
#1

I am trying to send packets from my Arduino to my desktop. Currently, the Arduino does connect to the network but fails when trying to call endPacket(). Here is the code and log:

/*
  WiFi UDP Send and Receive String

 This sketch wait an UDP packet on localPort using a WiFi shield.
 When a packet is received an Acknowledge packet is sent to the client on port remotePort

 Circuit:
 * WiFi shield attached

 created 30 December 2012
 by dlf (Metodo2 srl)

 */


#include <SPI.h>
#include <WiFi.h>
#include <WiFiUdp.h>

int status = WL_IDLE_STATUS;
char ssid[] = "NETGEAR31"; //  your network SSID (name)
char pass[] = "oddearth926";    // your network password (use for WPA, or use as key for WEP)

char  ReplyBuffer[] = "acknowledged";       // a string to send back

WiFiUDP Udp;

void setup()
{
  //Initialize serial and wait for port to open:
  Serial.begin(9600);

  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) 
  {
    Serial.println("WiFi shield not present");
    // don't continue:
    while (true);
  }
  // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED)
  {
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:
  }
  Serial.println("Connected to wifi");
  printWifiStatus();
  Serial.println("\nStarting connection to server...");
  if(!Udp.begin(8765))
  {
    Serial.println(F("failed"));
  }
  
  // if you get a connection, report back via serial:
}

void loop() 
{
  IPAddress ip(10,0,0,5);
  int port = 8766;
    // send a reply, to the IP address and port that sent us the packet we received
    if(!Udp.beginPacket(ip, port))
    {
      Serial.println(F("Failed beginning packet"));
    }
    Udp.print(ReplyBuffer);
    if(!Udp.endPacket())
    {
      Serial.println(F("Failed ending packet")); 
    }
}


void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your WiFi shield's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm");
}

Attempting to connect to SSID: NETGEAR31
Connected to wifi
SSID: NETGEAR31
IP Address: 10.0.0.34
signal strength (RSSI):-64 dBm

Starting connection to server...
Failed ending packet
Failed ending packet
Failed ending packet
Failed ending packet
Failed ending packet
Failed ending packet

It continues to spam “Failed ending packet” until I terminate it. Any ideas?

EDIT: Updated firmware and it works.

#2

Charsmud:
I am trying to send packets from my Arduino to my desktop. Currently, the Arduino does connect to the network but fails when trying to call endPacket(). Here is the code and log:

::::SNIP:::

It continues to spam "Failed ending packet" until I terminate it. Any ideas?

EDIT: Updated firmware and it works.

Charsmud,
I wondering if you are familiar with UDP. If not, then you should be aware that it is NOT a socket. It is a one (1) packet at a time protocol. That means it sends one (1) packet and NOTHING ELSE. It does not wait for a response, nor it is possible to do anything -- except know it has been sent. And there is no way to know the packet arrived at the destination computer -- unless there is a program on that other computer to tell you it received a UDP packet.

Are you aware of all this?

Jesse

#3

I wondering if you are familiar with UDP. If not, then you should be aware that it is NOT a socket.

UDP uses a socket to send the packet.

And there is no way to know the packet arrived at the destination computer -- unless there is a program on that other computer to tell you it received a UDP packet.

Normally that is true, but if the destination device is on the localnet with the sending device, like this one is, there is a way. UDP.endPacket returns 1 if the next device en route to the destination device accepts the packet. If the destination device is on the same localnet, it is the "next device" en route.

Just so you are aware...

edit: Since this is a WiFi shield, there is no way to determine if the packet was delivered to the destination, even if the destination device is on the same localnet. The WiFi shield cannot establish an ad hoc connection, so the next device en route will always be the access point (router).

#4

I am indeed aware of how UDP protocol works, I have dealt with it in the past. As I stated before, I fixed the problem by updating the firmware on the WiFi shield.

#5