Azure Sphere Guardian 100 - Review

Table of contents

RoadTest: Azure Sphere Guardian 100

Author: karlleofrsson

Creation date:

Evaluation Type: Development Boards & Tools

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?:

What were the biggest problems encountered?: It was in fact the wrong tool for the job.

Detailed Review:

First impressions of a company or a product are vitally important, and the first impression of the company is that the sample was dispatched from Chicago, Illinois, United States on 17th January and delivered to me in Tintagel, Cornwall, United Kingdom on 23rd January.  That is four working days, so well done to Newark and to UPS.  The unit arrived in a small but substantial shipping carton, which was scuffed on a corner or two, but otherwise undamaged.

Inside this shipping carton, nestled in a small amount of bubble wrap, was the actual box for the product.  No fancy graphics or distracting pictures.  No silly colours or pointless stuff.  The box was a crisp white, with a neat AVNET logo in the centre, and a couple of compliance notices on the back.  Simple, elegant, professional.  It says this is an AVNET product, S/N *******, and that is all.

On the negative side, because there must be balance in all things, it does not say what the AVNET product is.  It does not say “Azure Sphere Guardian-100”, or any part of that.  This is not an issue if it is only going to be supplied direct, but if it is going to be provided to any retailers, then perhaps some indication as to what is in the box could be considered to be useful.

Opening the box, by lifting a single flap at one end, one is greeted with some paperwork.  By a picture of the device, there is a heading of Azure Sphere Guardian-100, and the next words you see are Thank You for selecting Guardian-100.  Two words, Thank You, so simple, yet so rare nowadays.

The rest of that single sheet of paper, or at least the first side, is a short five step guide to installing both the hardware and the software for the device.  At this stage, looking at the Azure Sphere Guardian-100 itself, I can see that the device will not do the job that was specified on the application to Element-14.  The USB connection on the device is a USB type B, the same as on the equipment that is was going to be tested with, so it cannot be tested with that equipment, and it cannot be used for that job.

The idea was to connect the Azure Sphere Guardian-100 to a wide format printer, that has a USB connection, but has no current network capacity, using this device to provide a network connection, and keeping that part of the network secure.  Clearly, that is not going to work, at least directly, so another way of testing this device will have to be found.

The rest of the packaging, under the paperwork, was a foam block with the device sat neatly it the centre.  Very safe, very secure.  Under this, laid out quite neatly, were an Ethernet cable, a USB cable, two large adhesive pads, and a pair of screws, giving two ways to mount he unit, adhesive cable mounts and cable ties.  Everything to set the device, where you want it, with the cables, and keep it all neat and tidy.  Including cable ties and pads is unusual, but nice to see.

A USB adaptor was obtained, to allow the supplied cable to have a USB-B connector at both ends.  We all know that with seven different connectors now, the Universal Serial Bus is not very Universal, but it never really has been.  It was then time to set up the printer that it was to be tested with.

With everything set up, it was clear to see that the Azure Sphere Guardian-100 was not receiving any power, either from the USB side, or from the RJ45 side.  It doesn’t have an independent power supply, so would be expected to draw power from the USB side, but this is not going to happen.

It is quite clear, that what I wanted this new device for, is not going to work, at all.  The next stage will be to connect it directly to the computer, and see what happens there. Simply connecting the Azure Sphere Guardian-100 device to the computer, allows a connection to the ADSL router, but does not allow a connection to the Internet.  This may be what the device is designed to do, therefore it was disconnected again, to follow the one side of A5 instructions.

I have been using computer hardware for so long, that I have a tendency of taking it out of the box, plugging it in, and getting on with the job at hand.

Instructions have for years started with Do Not Connect This Equipment To The Wrong Supply and Do Use Attempt To Use This Electrical Equipment Under Water.  The Surface Of This Heater May Become Hot In Use is quite common now as well.

As such, I have come to treat instruction with disdain, not undeserved, and I don’t usually bother with them.  However, RTFI !  When all else fails, Read The “Flippin’” Instructions.

In the course of this, there was a lot of talk about different programming languages and examples of code on the various linked web pages, and it became clear that this device was nothing to do with network management, or security.

It was not a connection controller a secure network channel or even a hardware firewall.  It was a programming and application development device.  As such, I have to suggest that the name Azure Sphere Guardian-100 is misleading, as Guardian suggests a firewall of some kind, and AVNET suggests Advanced Networking.

I do not know a damned thing about programming languages, beyond their existence, and being able to perform basic tasks in Windows DOS Command or Ubuntu Terminal.  As such, this device has no use for me, and I have no idea why my application to Element-14 was accepted, as I thought I had made it clear what I was hoping to achieve with this device.

As I am not able to set the Azure Sphere Guardian-100 up complete, or use it as intended, I am unable to comment on the suitability of the device for its intended use, which is a shame, but there it is.

From what I can see, it has a compact and tidy design, and it well present in a secure and complete package.  That said, the name could be considered misleading, and others could make the mistake that I did. I have given a 5/10 rating, as I was pleased with how the device was presented, but I was unable to test it properly.

  • My proposed method of testing and the device it was to be used with was clear in the application.

    I discussed the situation at length with the administrators, including proposing to return the device.
    What I submitted was agreed several days ago.

    Your analogy with the bike and the car is a good one though, I can't argue with that.

  • As a fellow road tester I can empathise with your situation.


    Although your road test came to an abrupt end when you could not readily find a way forward for your intended application, what you rightly and correctly have highlighted, in my opinion, is "user assumption". I can see where you are coming from and sometimes product marketers need to see this too as more often than not they are so caught up in their own way of thinking.


    I agree, the use of USB - B as the only way to power the device is a design fail, in my opinion. A 2-way screw terminal could readily have been provided for power purposes. The use of the USB-B format is also rather outdated, considering we now have USB-C which offers better flexibility on voltage and speed (this is only USB 2.0 as well) etc. This also possibly highlights another flaw on the USB side (I still need to investigate), i.e. this is not USB-OTG either nor does it behave as a USB host.

  • A bit like buying a bike, thinking it is a car then rating it 30/60 because it didn’t meet your expectations and you have to pedal to make it go anywhere.


    Maybe you should return it and let someone else review it?


    Regarding your application, I think your proposal was probably taken at face value, thinking you knew what you were talking about. In fact, that’s one of the questions.