How to check if UIPClient got disconnected? about arduino_uip HOT 4 CLOSED

That is happening by design of tcp. A connection is being seen as 'established' until it's terminated
(http://en.wikipedia.org/wiki/Transmission_Control_Protocol#Connection_termination). Unplugging a network-cable does not terminate an established connection by itself. Of course, without physical connectivity packets will not arrive at their destination and thus will not be acknowledged which eventually results in a timeout (resulting in a connection being terminated by each side independently). After that has happened client.connected() will return false. You have to activly send data for this to happen, just calling 'client.connected()' in a loop will never(!) time-out as there ain't no outstanding ACK-packages.

You might want to checkout https://github.com/firmata/arduino/blob/configurable/utility/EthernetClientStream.cpp which is an implementation of a 'persistent' Stream that reconnects automatically.

from arduino_uip.

Hello Norbert,
Thank you very much for your reply.

I'm pretty much of a newbie in Arduino and I don't know how to implement that EthernetClientStream into my source.

Would you be so kind to provde me a simple sample how to use EthernetClientStream together with UIPEthernet library?

This is a snippet of my currently used source:

#include <UIPEthernet.h>

EthernetClient client;

void setup() {

// Initialize all the network stuff, IP, mac, dhcp, ...

}

void loop() {

if (client.connect(IPAddress(192,168,171,1),1012))
    {
        Serial.println(F("Connected successfully"));

        while(client.connected())
        {
            // Receive data from telnet server...
            // Even if I unplug the network cable client.connected() is still true/1 .....
        }

        Serial.println(F("Got disconnected. Reconnecting..."));
                client.stop();
    }
else
    {
      Serial.println(F("Connection failed, retrying..."));
    }

Thank you very much!

from arduino_uip.

have a look at https://github.com/firmata/arduino/blob/configurable/examples/ConfigurableFirmata/ConfigurableFirmata.ino#L129
After having created an instance of EthernetClientStream (as in ConfigurableFirmata.ino) you can begin using all methods of Stream-class (http://arduino.cc/en/Reference/Stream).

How to detect whether the stream is actually connected? Whenever the stream is disconnected the methods read() and peek() would return -1, while write() returns 0 in this case.

from arduino_uip.

closing as there's no further feedback

from arduino_uip.