System on modules vs. hacker boards

Electronic Specifier spoke with Ohad Yaniv, CEO of Variscite to understand the advantages of using a system on module (SoM) over a hacker board and what the difference is between the two.

Hacker boards are not new, they have always been available on the market – commonly used examples include Beaglebone, Udoo, Arduino and the Raspberry Pi. They are a great means for students to access the embedded market and an easy way for them to prototype their devices. More importantly, they are accessible.

Hacker boards are increasingly serving as the foundation of technology projects found in IoT, wearables, robotics, and portable devices.

Starting as low as $15, these boards are part of a new manufacturing trend supported by a community of hobbyists and DIY developers that use low-cost hardware components and open-source software to create mini-computer platforms.

Hacker board or SoM?

As highlighted, hacker boards have their advantages but, on the flip side, there are also some disadvantages. Yaniv explores some here:

1. Lifecycle

“If you look at our typical Variscite customer that goes into production for five to 10 years, some of them are certifying their products as medical devices or for industrial applications and therefore going through a lot of investment to ramp up their production and certifying the end products for use in different states.

“First of all, they need to be able to ensure a long lifecycle for the product. They need to know that the components within the product maintain stability during the lifecycle and don’t change.”

If anything changes, designers need to be able to receive notifications in advance, allowing them to recertify the products in time to meet regulatory requirements. This is where hacker boards are at a bit of a disadvantage, says Yaniv.

“Hacker boards are constantly being updated. As far as the manufacturer is concerned, this is for positive reasons – upgrading the processors, updating features, and adding more interfaces etc. But for the embedded designer, this is actually a disadvantage because they can’t upgrade their product during its lifecycle without redesigning it and the hacker board with the specific configuration that they use will soon not be available.”

This is one of the reasons why more designers are moving toward a SoM-based design. Even though hacker boards offer a lower cost alternative, a SoM-based design can give designers more control over the product.

2. Customisation

Another important factor to consider is that adjustments and customer customisations are not really possible when using a hacker board. “Hacker boards are basically a single board computer with connectors, a certain dimension, and a certain type of connectivity. [Designers] can only wire up some of the board’s connectors, close it in a generic box and use it as is.

“Most designers need more than that, they need to have everything certified, tested, mechanically designed to sustain thermal management, and fit the hardware to their specific size and shape requirements. You can’t do that with an off-the-shelf single board computer.”

With a SoM option, designers can take the off-the-shelf element (which is the system on module) and tailor a carrier board to meet the thermal, mechanical, and functional requirements and add a specific IP to the electronic board, while still maintaining the advantages of an off-the-shelf solution.

3. Technical support

Another disadvantage of a hacker board would be the technical support. There is, of course, a very active community for hacker boards but if you compare that with what a SoM provider can offer, there is a notable difference.

Yaniv says: “If you look at what Variscite is doing for its customer: in addition to the vast online documentation, customers get direct access to the technical team that develops the products. The team is located worldwide so the engineers can answer questions relating to hardware and software integration in their time zone. We even take the time to review product design schematics which is done for free. By that we can make sure that the integration of the SoM to their product was done properly, saving them time and resources which is obviously very critical. No community member will do this for you.”

4. Availability

During the last year or so, Variscite has seen a lot of hacker board customers approaching them looking to redesign their product using a SoM.

“This is happening because of the low availability in the components market. When you enter the Raspberry Pi website for example and place an order, there is about a 52-week lead time,” Yaniv notes.

Variscite’s lead times are significantly more attractive because, at the start of the crisis, the company was well-positioned with stock for many components. “Once we got the sense that things were going to get worse before they got better, we further increased our stock levels. This allows us, even today, to sustain a lead time that is quite short.”

5. Temperature

Some applications require support for industrial temperature grades at -40 to 85°C. All of Variscite’s system on modules are available in these temperature grades. Most hacker boards do not because they’re not designed to support industrial purposes.

“Variscite is making sure that all the components are certified for industrial temperature grade on its industrial certified modules. This is not something that many hacker boards can state.”

How easy is it to migrate from a hacker board to a SoM?

“It's actually not that complicated but, in any case, that is where good technical support is very helpful. We review all the interfaces, the SoM with their device, the schematics and then also their layout design and make sure they didn't make any mistakes.

“We are seeing customers that were able to do the switch within a couple of months and get their product out within three months from the design start. And this is close to a miracle considering the situation in the market today,” Yaniv concludes.

If pricing is your sole determinate for value, hacker boards may seem like the way to go. But for those looking to build embedded industrial products with the best combination of reliability, performance and price, choosing a high-quality SoM instead of a hacker board ultimately offers the best overall value to customers.