Weird output from serial port

[Ivan Popov]

Hello,

In short, my use case is that I'm trying to onboard a Thingy:91 to AWS IoT Core through the available code sample following this tutorial (and the related library description linked in it).

What I did successfully was: 

1. I managed to provision the certificates to the device (I can see them listed along with the default ones with the AT%CMNG=1 command).
2. I created a project from the sample (aws_iot), edited the required properties (AWS MQTT endpoint, device_id, topics, ...) and managed to build it in VSCode for the thingy91_nrf9160_ns target.
3. I flashed the resulting app_signed.hex file on the device with the Programmer application (it took ~50 seconds).

However, on rebooting the device in regular mode I get nothing in AWS IoT Core - nothing in the topics, nothing for the shadow.

I tried to get some clues from the serial terminal but all I get is a blank, black terminal. (Interestingly executing commands in the LTE Link Monitor is successful ...)

I tried to play a bit with the ports and their options but the only visible result was on the second (not the default for any of the previously (successfully) executed operations) port and it looked like the wrong Baud Rats was given:

Any ideas on how to proceed and how to determine what might be wrong? I've followed the tutorials as closely as possible, yet we're here.

Best regards,

Ivan Popov

[Ivan Popov]

Hi,

No need to apologise - you just got assigned to the ticket.

On your first question: at first I tried with the Blinky example as shown in this video. I honestly don't remember if I ever needed to watch the output in a console, since the case is too simple and the Thingy blinked without any issues. I might try a hello_world style example or something involving console output specifically but due to my schedule I can try it tomorrow, earliest.

Here is the whole dmesg output after I connect the Thingy to the computer:

And here is output in the Serial Terminal (from the file) (the aws_iot sample is flashed on the device):

As for the brltty problem - I've had it before with another device (as you can see from my answer here), and I've removed it some time ago.

---

Now since my situation changed:

• device is visible in AWS, so I assume the sample works and the communication can be maintained through MQTT;
• from that perspective what I really need is the Asset Tracker v2 sample modified according my case;
• the build for the sample fails with the only change to it being the addition of the AWS properties in the respective overlay file (overlay-aws.conf) and the error is addressed in this ticket too:

... and since the problem is already different from the one in the title of the ticket, I'm not very sure if I have to close this and open another one, or we just can finish this here?

Best regards,

Ivan Popov