Introducing the Strato Pi Max

Sfera Labs’ first product was born by accident, certainly not from a carefully conceived business plan. When the second iteration of the Raspberry Pi came out in 2013—the Model B with 512MB of RAM—it was fast enough and had enough memory to run our own Supervisory Control and Data Acquisition (SCADA) platform, which we called HSYCO.

Based on this, we thought it could be a good idea to start selling an entry- level appliance based on our SCADA pre- installed on a Pi B+. But a naked Pi board cannot simply be put to good use in an industrial environment, typically installed in an electrical distribution panel, without something around it. So, we started thinking what would be required to have a proper product for this kind of application environment.

From wish list to product 

The core list of features we needed to add was substantial, but not intractable: (1) a very reliable power supply stage, (2) a hardware watchdog, (3) a real time clock with battery backup, (4) serial ports, (5) a few other things, like an internal buzzer and a secure element chip, and (6) a DIN-rail enclosure and terminal blocks for wiring power and signal lines.

There was nothing similar in the market back then, so we designed the circuit board with all these features and a standard DIN-rail enclosure. We liked it, it served our needs well, and we started thinking that it could be interesting to others. And this is how Sfera Labs and its first product, Strato Pi Base, were born!

Versions proliferation

Since the seed was planted, other needs quickly arose, both from us and from the market. To address these needs, we grew the family with a range of different products, all variants of the original idea, with specific features added, like a version with an integrated uninterruptible power supply (UPS), one with CAN bus, another with integrated digital and analog I/O, and so on.

From Model B to Compute Module

The introduction of the Raspberry Pi Compute Module allowed us to gain much more flexibility in the hardware architecture design, as well as the mechanical form factor, and a whole range of new products based on the Compute Module naturally evolved from the original design.

Growing complexity

Most of Sfera Labs’ customers integrate our products into larger, complex solutions and need very long-term support and availability from us. As a result, while we keep adding new product variants, we never discontinue older versions. This, of course, leads to an exponential growth in the number of products while the features and complexity of each product is also naturally increasing.

Lessons learned

All these products are, in a sense, monolithic, each with a different mix of features. And some of these products are quite complex, with part number counts around 1000 components. One important lesson learned was that complexity quickly gets overwhelming. Another was that complexity also significantly increases risks. A single part not being available from one supplier could grind production to a halt, and a product with a large unique parts count is statistically more at risk.

It became clear to us that if we wanted to keep fulfilling a wider range of needs, then we needed to design a new hardware architecture that was more flexible and more expandable while still incorporating the core features of all our current products.

Getting to Strato Pi Max

All of this brings us to the design of Strato Pi Max, which is an industrial edge server based on the Raspberry Pi Compute Module 4.

The Strato Pi Max incorporates the features of all our other products, largely reusing the same building blocks in many critical areas, and adds up to four internal expansion slots, as well as other features, some made possible specifically by our use of the Compute Module 4.

Compared to our other products, many non-core features have been moved to expansion boards, vastly increasing the options available to customers, and significantly reducing costs when features are not needed.