Telemetry data with Raspberry Pi 3, Windows 10 IoT core and Azure IoT Hub

I had a great time getting the Raspberry Pi 3 set up with Windows 10 IoT Core, a BME280 temperature sensor, and sending temperature data to Azure IoT Hub.  This was my first experience with each of these components, so I was learning as I went.  Working in technology, if you’re not used to or not comfortable learning as you go, you might want to take a step back and re-examine why.  Its well known that change is common in this field, and we should embrace the unknown as opportunities to learn and grow, not merely stay in our comfort zones.  Staying in your comfort zone will get you left quickly behind.  I’m reminding myself of this as much as anyone else, but I digress.

First off, Windows 10 IoT Core.  Mind blown.   Extra points for exceeding expectation.  This is a really useful  operating system geared toward IoT devices, including the Raspberry Pi.  I didn’t know what to expect, and was super stoked about how easy it way to set up.  I was expecting to have lots of trial and error, set up time, guessing, incompatibility and a steep learning curve.   But with Windows 10 IoT core, not only flashing my micro-SD to install it, but setting it up and getting it working with my Raspberry Pi was a breeze.   Here’s  a quick step by step to get started.

1. Download and install Windows IoT Core Dashboard
2. Insert your SD card into your computer and navigate to the ‘Setup a New Device’ tab in the dashboard
3. Select the version of IoT Core you want to install, a name for your device, and an administrator password
4. Click ‘download and install’. The image is downloaded from the internets and installed on the card

You’re good to go now.  Slide the SD card into your PI and boot it. The IoT Core Dashboard should recognize your PI on the network, and it will appear on the My Devices tab.   If it does not try reading this.    When you see the device in the IoT Dashboard, right click it to open a browser window, sign in with the admin user name and password you provided, and you will be interacting with the OS through the Device Portal.

Windows 10 IoT Core has some pretty neat tools built in that you can navigate to through the device portal.  You can view installed apps, which apps are running, as well as start and stop apps.   There are even sample apps you can deploy to your device and run.

Windows 10 Iot Core App Samples

View CPU, View memory, I/O and network usage

Viewing Resource Usage in the Windows 10 IoT Core Viewing Available Networks in Windows 10 IoT Core Device Portal

View available networks

Viewing Available Networks in Windows 10 IoT Core Device Portal

For this post, I’m going to demonstrate how I was able to use the BME280 with the Raspberry Pi and Windows 10 IoT Core to send temperature data to Azure IoT Hub.  One of the great things that attracted me to Winows 10 IoT core was the ability to write C# code to access, interact with and control the various components of the Raspberry Pi.  For this example, I was able to use Visual Studio Community Edition, and mix and match some samples I found online either through the sensor vendor or MSDN.

So now to the fun part and back to ‘mind blown’ when I was actually writing C#, not Java, not Python, not Node.js, C# to interact with the Pi, I/O pins and everything.  We’ve all got our favorite languages, C# happens to be mine.  Not only that, but I was able to send messages to the Hub.

The IoT Hub is interesting and revolutionary.  I say revolutionary because I remember not long ago when such concepts were not available and easily accessible to the masses.  There were no (limited) options to send data into a nebulous cloud endpoint, with virtually unlimited scale, and plug in any number of listeners which then can take action via any number of workflows or triggers.  There are solutions I’ve built in the past that could have benefited from using the Hub.  I wish I could go back and retrofit these solutions using the Hub now.   Sending temperature data, or any other data to the IoT hub, and for that matter, the Azure Event Hub kind of implements set and forget in a new way, sort of a send and forget.   Get your data up to the cloud and handle it there.  The Hub acts as an abstraction layer between ingestion and processing.  Moreso, a “component or service that sits between event publishers and event consumers to decouple the production of an event stream from the consumption of those events”  This is easily understated and misunderstood.  Its truly remarkable, and also made easily available at scale with Azure.

Let’s dive into the code.  I’m using an open source library to access the temp readings from the BME280 sensor.  First, I just new up a timer to call the _timer_Tick method when the app starts and the entry point is hit (OnNavigatedTo event of the main page)

Then in the timer tick event, I read the temp from the sensor

Then send it to the hub using the Microsoft Azure Devices Client

Don’t forget to new up your devices client with your hub connection string and device ID, which you get when you set up your hub and register your device.

To deploy this app to your device, right click on the project in Visual Studio, then click properties. On the properties page, select the Debug menu item, then set “Remote Machine” as your target device.  Set the IP address of your remote machine in the Remote Machine setting.  This will deploy the app to the IoT device, and allow you to debug it.

Deploying to Windows 10 IoT Core from Visual Studio

Now let’s see the data in real time as it arrives in the hub. To do this, we’ll download, install and run the Windows Device Explorer.   Enter your hub connection string on the connection string tab.   Your device will appear on the management tab.  Select that device, then click on the data tab and click monitor.  You should see the telemetry messages appear as they are sent to the hub.  Here’s mine:

View device to cloud messages using Device Explorer for IoT Hub

So there you have it. Now imagine scaling this to 1000 devices, then building a reporting and monitoring solution from this. Happy coding!