Azure digital twin explorer is not showing telemetry data in twins

Shankar Parab 0

I have connected "Raspberry Pi Azure IoT Online Simulator" to stream data into Azure IoT hub. IoT Hub is sending that data to azure function via EventGrid. I have written python code for Azure function to take data from Event Grid and send it to Azure digital twins. I have added model in Azure digital twin explorer and created new twins with same name as IoT Hub device name. But Azure digital twins is not reflecting the temperature and humidity data.

Shankar Parab 0

Here is my Azure function python code

import logging
import os
import json
import azure.functions as func
from azure.eventgrid import EventGridEvent, EventGridPublisherClient
from azure.digitaltwins.core import DigitalTwinsClient
from azure.identity import DefaultAzureCredential

# Set up logging
logging.basicConfig(level=logging.INFO)
log = logging.getLogger()

# Set the environment variables for Azure Digital Twins
# adt_instance_url = os.environ['ADT_INSTANCE_URL']
adt_instance_url= "https://xxxxx"

# Create the credential object and Digital Twins client
credential = DefaultAzureCredential()
adt_client = DigitalTwinsClient(adt_instance_url, credential)

def validate_event(event: EventGridEvent):
    if event and event.data:
        payload = json.loads(event.data)
        device_id = payload["systemProperties"]["iothub-connection-device-id"]
        humidity = payload["body"].get("humidity")
        if humidity is not None:
            log.info(f"Device:{device_id} Humidity is:{humidity}")

            update_twin_data = [{
                "op": "replace",
                "path": "/humidity",
                "value": humidity
            }]
            adt_client.update_digital_twin(device_id, update_twin_data)

Shankar Parab 0

This is my model

{
  "@id": "dtmi:example:Room;1",
  "@type": "Interface",
  "displayName": "Room",
  "contents": [
    {
      "@type": "Property",
      "name": "humidity",
      "schema": "float"
    }
  ],
  "@context": "dtmi:dtdl:context;2"
}

1 answer

Sander van de Velde 29,196 Reputation points MVP

2023-05-20T20:36:31.6333333+00:00

Hello @Shankar Parab ,

although I am not familiar with the details in Python, your code seems to resemble a lot of the C# examples seen here.

There are two things I can think of right now.

First, be sure your Azure Function has rights/permissions to alter twins in Azure Digital Twins.

Also, you are using 'replace'.

I remember this works well if the twin property has a value already.

Please compare your code with these C# examples. And try out the C# examples next to your Python code.

If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. All community members with similar issues will benefit by doing so. Your contribution is highly appreciated.
Please sign in to rate this answer.
Anh Dinh 40 Reputation points

2023-07-29T08:50:51.36+00:00

Hello, I am doing the same thing as you and also get stuck in the same problem ( Azure Digital Twin not updated). If you already fix the problem or have any useful information, can you share with me?

Sander van de Velde 29,196 Reputation points MVP

2023-07-29T09:06:19.48+00:00

Hello Anh,

I use C#. Here is the full example.

Have you given the Azure function enough rights (ADT owner) to manipulate the twins?

Which error do you get from the Azure Function execution?
Sign in to comment