Friday, August 4, 2017
VISUALIZING REAL-TIME SENSOR DATA WITH AZURE WEB APPS
- Layout for this exercise:
* This exercise is based in the previous one
1 - Creating the Web App
- The goal of this exercise is to visualize real-time sensor data received by an IoT hub by running a web application that is hosted on a Web App.
- Starting from the Azure portal, clicking New -> Web + Mobile -> Web App:
- Filling the required data, like App name, Resource Group, etc .. and pinning to the Dashboard:
- The Web App starts the deployment process:
- An URL is generated that later will be used to visualize real-time sensor data:
2 - Adding a consumer group to the IoT hub
- Consumer groups are used by applications to pull data from an Azure IoT Hub.
- Going back to the Azure portal and opening the IoT Hub:
- Clicking Endpoints -> Events:
- Entering a Consumer group name and saving:
3 - Configuring the Web App to read data from an IoT hub
- Opening the Web App:
- Clicking Settings -> Application settings:
- Entering two key/value pairs. The first one corresponds to the Connection String obtained in previous exercises, the second one refers to the Consumer group name:
- Enabling Web sockets:
- Going to Deployment option -> Choose Source -> Local Git Repository:
- Setting up authentication with username + password:
- The Web App is eventually successfully deployed:
- From Overview, let's copy the Git clone URL that will be used later:
4 - Uploading a web application to be hosted by the Web App
- Now, let's go to the Raspberry Pi device and open a terminal window.
- Entering these commands using:
a) Git clone URL from the previous point
b) appropriate authentication credentials (username + passwords) from the previous point
- Running the simulated Temperature/Humidity sensor device:
- Browsing the URL generated before:
- Finally, the Temperature/Humidity real-time data generated by the simulated device is visualized:
Thursday, August 3, 2017
MICROSOFT AZURE (2): CONNECTING A SIMULATED DEVICE TO AN IoT HUB USING NODE.JS
* This exercise is based on the previous one
1 - Creating a device identity
- CreateDeviceIdentity.js creates a device identity and associated security key to connect a simulated device app.
- Running this console app generates a unique device ID and key that the device can use to identify itself when it sends device-to-cloud messages to IoT Hub.
- New folder:
- Checking that node and npm are correctly installed:
- npm creates a json package, just accepting the default options:
- Installing the azure-iothub service SDK package:
- Writing the CreateDeviceIdentity.js file:
- It is important to notice that the variable connection string holds the "connection string - primary key" obtained in the previous exercise:
- Also, the deviceID must be entered:
- Running the program, a new Device key is generated:
- The Device key is written down or copied and added to the document with all the parameters and keys:
2 - Receive device to cloud messages
- ReadDeviceToCloudMessages.js displays the telemetry sent by the simulated device app, reading device-to-cloud messages from IoT Hub using the AMQP protocol.
- New folder:
- Creating a new json package file and accepting all the default options:
- Installing azure-event-hubs package and saving it:
- Writing the program ReadDeviceToCloudMessages.js:
- As before, it is important to notice that the connection string key must be introduced in the variable connectionString.
3 - Simulated Device
- SimulatedDevice.js connects the IoT hub with the device identity created earlier, and sends a telemetry message every second using the MQTT protocol.
- New folder:
- json package:
- Installing azure-iot-device and azure-iot-device-mqtt:
- Writing the program, and using the connectionString variable with the Device key value originated at the section Create a device identity (point 1 of this exercise):
- All of these parameters must be carefully entered:
4 - Running the application
- To run the two applications a separate console must be used, so that the communication between the simulated device and the IoT hub can be displayed.
- Running SimulatedDevice.js to send telemetry data to the IoT hub:
- Running ReadDeviceToCloudMessages.js to monitor the IoT hub: