IoT first Wifi connection failed

[tidjidi]

Hi team,
I made some Arduino cloud experiences, and discovered that systematically, the first Wifi connection trial failed, while the second is always fine. Very odd!
Thanks to DBG_VERBOSE mode, I noticed that Wifi Ids (SSID, PASS) are not loaded the first time...

So, digging a little bit in the libraries (ArduinoIoTCloud and Arduino_ConnectionHandler) to find my way, I created a patch to avoid this situation (maybe it's not the optimal solution, but for me it does the job! And that's fine).

Within the file WiFiConnectionHandler.cpp, in the method WiFiConnectionHandler::update_handleInit(), I added this short test (line 95 in release1.2.0 - within the test if (WiFi.status() != WL_CONNECTED)):

  if (WiFi.status() != WL_CONNECTED)
  {
     if (strlen(_settings.wifi.ssid) == 0) {
      DEBUG_ERROR("Network settings absent");
      return NetworkConnectionState::INIT;
     }
...

And as it worked with that patch, I didn't look further to find a reason why Wifi Ids are not received at that stage!

Thanks for all.
Thierry

[andreagilardoni]

Hi @tidjidi!
Thanks for your report! Can you please provide more details? Which board are you using?

[tidjidi]

Hello @andreagilardoni
My trials were done with an Arduino UNO R4 Wifi. (examples from the Plug and Make kit)
I first performed the sketches on the Arduino cloud, uploaded through serial communication to my local UNOR4. Then I noticed that strange behaviour while connecting. Consequently, I kept back my sketches on my computer for local compilation with local Arduino environment.
Of course, with first local compilation, I got the same behaviour for WiFi connection, and I decided to go deeply in Arduino's libraries (ArduinoIoTCloud, Arduino_ConnectionHandler,...) with little retro-engineering... and setting "MessageLevel" (Arduino_CloudConnectionFeedback) to DBG_VERBOSE, I noted that when the trial connection failed, the SSID was not known yet (while when the SSID is set, the connection is immediate!).
I did not analyse why the SSID is not transmitted yet for the first connection trial... but I found a location within the code of WiFiConnectionHandler.cpp (Arduino_ConnectionHandler library) where I set up the little piece of code I gave you above:
when the test on the wifi connection is not WL_CONNECTED. I just avoid the fail return, with the consequence of the sad emoji display on the LED Matrix.
Hence, I did not solve the trouble; reason of my message for you to analyse why the connection tried to connect while it has not received the SSID/PASS data...

Hope this helps!