Connect ESP32 to EventGrid over MQTT with Nanoframework

Although I mainly work with Azure IoT Edge solutions, once in a while I program for constrained devices.

These devices are not extending the cloud but devices like the ESP32, are quite powerful in their own way and support wireless communication too.

This makes them perfect for IoT client solutions.

From all client programming platforms, I love to program using the Nanoframework platform the most.

It makes it easy to write C# code for embedded systems so even with limited embedded devices knowledge, developers are successful in building embedded systems.

Last year, I wrote an article about my Azure cloud-connected coffeemaker (a tribute). It was completely written in C#, complete with Azure IoT Hub integration, GPIO, and sound generated by an MP3 player.

For this blog post, I checked out how the Nanoframework can connect to the new MQTT support for the Azure EventGrid namespace:

Let’s see how we securely connect an ESP32 and have it communicate over plain MQTT.

Fun with NanoFramework, running .Net C# on ESP32

During the latest Flight into Azure IoT, the long haul event, a number of devices were connected to Azure IoT.

One of them was an ESP32 running a .Net application written in C#.

Wait!

.Net, known for running applications on Windows and Linux, on PCs, laptops, and in the cloud, Can also run on a five-dollar MCU?

Well, yes 🙂

Using the .Net NanoFramework it is made easy to write C# code for embedded systems:

Our mantra is about making it easy to write C# code for embedded systems! And all what we’re doing here is about that. This free and Open Source platform that enables the writing of managed code applications for constrained embedded devices.

.Net NanoFramework

During that TechDays UK event, that ESP32 device was connected to Azure, sending simulated telemetry to an IoT Hub (read from files while being controlled using Direct Methods).

In this post, we check out how to get started with the .Net NanoFramework and have some fun with it.