Secure Edge Retrofit based on Certified Azure Sphere SoC module

A use-case with secure monitoring and remote control of equipment in franchised stores has recently been implemented using Guardian 100 (based on globally certified dual-band Wi-Fi Azure Sphere SoC module from Avnet)

Aspects addressed in this Azure Sphere Guardian-connected application, include remote management, output control and predictive maintenance, where legacy non internet-connected kitchen equipment gets securely interfaced via Guardian to the cloud (IoTConnect, powered by Microsoft Azure)



The power drawn by each blender appliance is measured using a multi-channel commercial power monitor and reported via Ethernet to Guardian.

Program logic in Guardian's Azure Sphere application matches current-draw profiles to which blender buttons have been pressed (ie. which smoothie flavors produced).


Dual-band Wi-Fi

Guardian securely sends via Wi-Fi this telemetry data to Azure-based IoTConnect, which charts current and other reported parameters over time within it's comprehensive device monitoring and management interface
A PowerBI based business dashboard is also provided, that provides insights and identifies trends from the captured database of Smoothie drink production data

Different output options can also be controlled remotely by franchise management, by making changes to the Azure Device Digital Twin that models the physical outputs of each connected-blender installation.



Guardian also communicates locally via USB with additional off the shelf hardware (Raspberry Pi fitted with Relay HAT and RGB LED array) to implement various outputs.
This enables (seasonal- or special event-) control of RGB lighting LEDs at each installation, as well as the ability to remotely disconnect blender appliances, in the event of unpaid franchise fees or a need for technical maintenance


System Block Diagram

The diagram below provides system-level detail of the hardware involved (for simplicity a single blender installation is shown)


Application Implementation

Summarized below are some key aspects of the implementation

  • A commercial power monitor reports via Ethernet to Guardian, the measured operating current and voltage of the blender appliance(s)
  • Guardian's Azure Sphere application logic matches the current profile with blender button pressed (ie. smoothie flavor produced)
  • Telemetry is securely sent via Wi-Fi from Guardian to the Cloud
  • IoTConnect cloud-based application charts current over time and identifies smoothie quantities and flavors produced.
    It also hosts a PowerBI business dashboard with analytics to extract visualizations that highlight trends and additional insights of customer purchased smoothie products over date and time.
  • Control of local outputs is implemented via Guardian’s USB interface to a slave SBC board’s relays and LED peripherals
  • Remote management via internet browser of the cloud-hosted Azure Device Digital Twin, to control local outputs:
    - RGB LED lighting array (for seasonal or mood effects)
    - Power-disconnect relay (for remote disable of the blender)


IoT in Action Demo

This use case will be demonstrated at upcoming trade show events. If you are in the New York area, consider registering for free attendance of the Microsoft IoT in Action live event in Manhattan (on Monday 1/13)
There you will have easy access to view this and other IoT enablement at the Avnet booth.

Registration is at:


IoTConnect - the "Easy-button" for Cloud-Connected Systems

Full-featured PaaS (Platform as a Service) solutions provided by IoTConnect, help connect devices quickly, generate new insights and enhance decision-making capabilities.

Included are device communication and management, data storage, app creation and enablement, robust security protocols and implementation of data science methodologies

A feature-rich toolkit enables developers to build and deploy connected IoT solutions, accelerating the product development process while reducing associated risks and costs

SaaS (Software as a Service) solutions based on IoTConnect (eg. Smart Asset Monitoring, Smart Healthcare, etc) cater for the needs of a variety of popular use cases


For more Information

For a quick overview of the Guardian 100 Azure Sphere IoT security solution, visit the following pages on the element14 community website:

Azure Sphere Guardian-100 product page

Azure Sphere Guardian-100 Hardware User Guide

Azure Sphere Retrofit to Existing Equipment

Azure Sphere guardian module simplifies and secures brownfield IoT (Microsoft blog 12/2019)


Based on the same certified Azure Sphere MT3620 module, dozens of use cases and detailed designs are viewable online for the versatile Avnet Azure Sphere Starter Kit, which facilitates easy prototyping and rapid way to get up to speed with this technology

Azure Sphere MT3620 Starter Kit product page

Azure Sphere MT3620 Module product page

Sensing the World - Winning Designs

Secure Everything - Winning Designs



Brian Willess of Avnet's Azure Sphere focused engineering team, should be acknowledged in this context for:

  • Defining and implementing multiple versions of Azure Sphere based power-monitoring solutions, and
  • Highlighting how Guardian 100 plus IoTConnect provide attractive options for secure, rapidly deployed IoT solutions