Your Arduino Uno is not in the network

My Blynk sketch using an Ethernet shield works fine except for when I leave it inactive for several hours. When I try to use it after those several hours Blynk will complain that “Your Arduino Uno is not in the network” and will fail to connect. When I bring up the serial console from the Arduino ide it immediately reconnects to the server or if I reset the Arduino it immediately reconnects. I’m running this on my University’s network so that could be part of the problem. I’m considering all options at the moment. Is there a way to test for a connection to the Blynk server? I’m thinking I could reset the Arduino if it fails to connect to the server over a period of time.

Hi, thank you for reporting. What blynk library version do you use?

Currently using the latest release 0.2.4, although I tried this on a mega using 0.2.3 and experienced the same problem.


As an option you could try 0.2.5-beta. It has more variants for manual connection control.

Also here is chance that it could be Blynk lib. bug.
@vshymanskyy please check if it could be an library issue.

I appreciate the quick response, I will give the manual connection a try and see what happens. However I wouldn’t be surprised if the issue is my University’s network.

It could be ethernet shield itself… But with manual connection handling you could for instance once in an hour close and reopen connection manually. It could be a solution for you.

Personally I have an ethernet shield that works for weeks with no problems.

As additional option you could try to enable debug it may give more info about your connection behavior.