Azure sphere digital twin connection issue for my device

Prathik 6

Hi. I have run simulator app and function app code from this link.
https://learn.microsoft.com/en-us/samples/azure-samples/digital-twins-samples/digital-twins-samples/

I published the function app and ran the simulated device code. It was working. I had created models and twin graphs in digital twin explorer. I could see the telemetry data updated.

But when I use my device it doesn't work. So I ran both my device(C programming) and simulated device(C#) together. I could see the output of both device on command prompt created during running the simulated device code.(which is the output from the functions).

Only difference is that my azure starter kit device telemetry is not updated on digital twin explorer.
I have also noticed that the temperature data is send to hub as "Content-type:Application/json" for simulated device and normal json data in my device. Could this be the reason for the issue.

If "Yes"!!!!, then how can I covert my device data to application/json format.
I used 21.04 version Azure Iot sample code to connect to Hub.
Please let me know if more info is needed. Thank you.

António Sérgio Azevedo 7,666 Reputation points Microsoft Employee

2022-05-30T15:24:20.943+00:00

Hello @Prathik ,

Can you confirm the data flowing from your real device to IoTHub, using a tool like Azure IoT Explorer?

Thanks
Prathik 6 Reputation points

2022-05-31T03:25:21.513+00:00

Yes. The data is flowing.
António Sérgio Azevedo 7,666 Reputation points Microsoft Employee

2022-05-31T10:36:14+00:00

Hello @Prathik ,
Can you check the output of system properties as well (In Azure IoT Explorer select the box "Show system properties"? What is the deviceID in your IoTHub, Output of Azure Function and then, does it matches with the device ID in ADT?

Thanks!
Prathik 6 Reputation points

2022-05-31T12:02:38.21+00:00

Hi @António Sérgio Azevedo . Thank you for your response.
The device device Id in the Hub matches the device Id in the ADT Explorer.

Here in the image the partition 3 data is the output of simulated device and the partition 1 data is the output of my Starter kit device.

In the 2nd image is the output with properties on iot explorer.The red line is my personal device and the yellow line is the simulated device.
António Sérgio Azevedo 7,666 Reputation points Microsoft Employee

2022-05-31T13:06:22.547+00:00

Thanks for your validation @Prathik , it is interesting the json being sent by both is pretty much the same. I do not believe that your issue is related with "Content-type:Application/json" line missing in your C code, as you mentioned. Though I have a slight suspicious that something may be wrong with the "iothub-connection-device-id" being to large for ADT? .

I believe you are using the azure sphere MT3620 and there is no way you can edit the device ID correct? Can you try changing the simulated device ID to the same ID as the one from Azure Sphere and see if it updates?

Thanks!
Prathik 6 Reputation points

2022-05-31T14:09:24.723+00:00

Hi @António Sérgio Azevedo ,

This is the IoT explorer output. 1st red coloured device Id is the Starter kit device and 2nd yellow coloured device Id is the simulated device.

The device Id in Hub matches the device Id in AD twin explorer.

The below image shows the output of Azure Function. The partition 1 data output is of my starter kit device and the partition 3 data output is of my simulated device.
Prathik 6 Reputation points

2022-06-01T16:57:45.37+00:00

Hi @António Sérgio Azevedo .
I deleted my device from hub and added a new device with same Id as name for the simulated device.
I am receiving the data now. I can see the updated data on ADT explorer. Why doesn't it work for my device then? I'm confused.

Thank you.
Prathik 6 Reputation points

2022-06-05T07:57:25.707+00:00

Hi @António Sérgio Azevedo .
I deleted my device from hub and added a new device with same name for the simulated device.
I am receiving the data now. I can see the updated data on ADT explorer. Why doesn't it work for my device then?

Thank you.
António Sérgio Azevedo 7,666 Reputation points Microsoft Employee

2022-06-08T10:27:28.923+00:00

Hello @Prathik ,

What is the c code you are using on your Azure Sphere Device?

Is it the one from here?: https://github.com/Azure/azure-sphere-samples/tree/main/Samples/AzureIoT

Thanks
Prathik 6 Reputation points

2022-06-08T11:08:25.747+00:00

Hello @António Sérgio Azevedo

Yes. I'm using the code from the link that you mentioned. But older version (21.04).
Thank you.
Prathik 6 Reputation points

2022-06-14T11:16:26.007+00:00

Hi @António Sérgio Azevedo .
Any reason on what caused the issue?

Thank you.
95504669 521 Reputation points

2023-03-05T11:27:56.4933333+00:00

Can i get a response for this issue please? It's been 8 months without reply. Thank you.
QuantumCache 20,031 Reputation points

2023-03-05T15:51:32.1966667+00:00

Hello @95504669,

Thanks for reaching out on this question!

We would request you to post a new question on this forum, so that community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.

1 answer

Edward Beistle 0

This question is old, but since there appears to still be interest in a solution, if the issue is indeed the content type, try adding these lines to AzureIoT_SendTelemetry() in azure_iot.c.

    if(IOTHUB_MESSAGE_OK != IoTHubMessage_SetContentTypeSystemProperty(messageHandle, "application/json"))
    {
        Log_Debug("ERROR: unable to set message content type.\n");
    }

    if(IOTHUB_MESSAGE_OK != IoTHubMessage_SetContentEncodingSystemProperty(messageHandle, "utf-8"))
    {
        Log_Debug("ERROR: unable to set message content encoding.\n");
    }