Laboratory Test Results

In a short sentence, USB Insight Hub passed the EMC and RED tests! This is a big milestone for the project and, to be honest, a huge overall relief. When I was researching the design considerations needed to mitigate EM (electromagnetic) emissions, there were too many unfortunate stories of failed tests on various projects, significantly delaying the schedule (and increasing the budget) due to additional modifications to the hardware. The worry was justified, as USB involves high frequency lines (both in USB 2 and USB3) with the subsequent risk of over-the-limit emissions coupled with a Wi-Fi capable module. Many factors played a role to obtain this result: a four-layer board with impedance control, a careful layout design with signal integrity in mind, the usage of the recommended passive filters in the communication lines, the use of ESD protections, and choosing a CE pre-certified ESP32 module.

The RoHS assessment of the electronic BOM, PCB, and solder process is already complete and assessment of the remaining additional mechanical components is underway. Also, we have been able to source a USB cable with the proper CE and RoHS certifications to be included with USB Insight Hub.

Moving to Production

With the confirmation of the positive results for EMC and RED on the first week of March, the payments to purchase the bulk of the BOM and to manufacture the PCB have been arranged. So far it looks like all parts are available in quantities to complete the first production run, and we expect to receive all the components by end of this month so we can start the PCB assembly the first week of April. Besides the assembly itself, there are the steps of programming and testing each of the units. For the latter, a program was developed to automate the tests and, in this way, considerably decrease the time required for this operation, but more importantly, reduce the risk of not detecting faults.

Automated Production Software

The automation of tests is, by itself, a project inside the project, and usually there is a tradeoff to be found between the expected production volume and the effort to automate the process: higher production runs justify more automation, while lower production quantities are usually ok with manual verification. Even though this initial run is low (around 200 units), we decided to automate as much as possible with 55 points of control to ensure that all features operate correctly and provide evidence, backed up by logs, that all units passed the tests.

Of course, this had the drawback of delaying the development of other software components, specifically to fix some bugs and improve certain features in the main UIH version that will be flashed in production. We hope this delay does not propagate to the general schedule, but if this is the case, we’ll keep you informed.

There are other small (but important) components still to be prepared before we have the finished physical product: labels, user guide, and packaging, all of which will be prepared in the following weeks.

A New Feature Addition

One outcome of automatizing the test is the creation of a new feature: the ability to configure USB Insight Hub in three different communication modes: USB 2 and USB 3 (default), USB 2 only, and USB 3 only. This provides an interesting feature that allows testing devices that have both interfaces in different modes.

Photo of the menu with hub options

I’m sorry this report does not have many photos, but once production starts, I will be able to get more visual material to post in the next update. In the meantime, please use our contact form if you have any questions, suggestions or comments.

Cheers,
David