[CM-474] Notify user if thing id is wrong / thing does not exist

[aentinger]

Device will stay in mode IOT_STATUS_CLOUD_CONNECTING and display an error message for the user to inform him about the probable cause of the error.

[ 1742 ] ***** Arduino IoT Cloud - configuration info *****
[ 1742 ] Device ID: * 
[ 1743 ] Thing ID: *
[ 1743 ] MQTT Broker: mqtts-sa.iot.arduino.cc:8883
[ 2287 ] WiFi.status(): 0
[ 2288 ] Current WiFi Firmware: 19.5.4
[ 2288 ] Connecting to "my-wifi"
[ 26835 ] Connected to "my-wifi"
[ 27505 ] Connecting to Arduino IoT Cloud...
ERROR - Please verify your THING ID

[ubidefeo]

can we use the same format for Serial output?
please replace Serial.println(...) with debugMessage("ERROR - Please verify your THING ID", 0).
this will also help in setting a custom Serial port (or Stream) to output messages to :)

[aentinger]

We can of course do this - one thing though: I image the debug messages to be removed from the code at some point in time - this message should always be displayed. What's your thoughts on this?

[ubidefeo]

We have other messages which are as important, such as the ones related to network hardware or loss of connection.
If the user has to rely on Serial to obtain this message I think that doing it via the current logging method will allow us to later implement better filters and not having to go look for this single occurrence of Serial.println(...).
As usual I'm open to better alternatives, Alex ;)

[aentinger]

Honestly I've got no better idea at this point. I'd feel better though if we coud assign constants to the numerical values used for signifying the debug message level so its better understandable what is important and what is not, e.g. 0 => LOG_ERROR, 1 = LOG_WARNING, 2 = LOG_INFO, 3 = LOG_DEBUG, 4 = LOG_BLABBERMOUTH and then call debugMessage accordingly:

sprintf(msgBuffer, "ERROR - Please verify your THING ID");
debugMessage(msgBuffer, LOG_ERROR);

[aentinger]

I've rebased the branch on top of the current master and am therefore ready to merge 😉

[ubidefeo]

Well done, @lxrobotics
you can merge when you want