Why now is the perfect time to put a single-board computer at the heart of your IoT designs

Mark Patrick, Mouser Electronics

The opportunities presented by the Internet of Things (IoT) are immense, and are already transforming the way we live, work and play. One of the biggest transformations currently underway is in industry, where initiatives such as the German government’s Industry 4.0 are pushing manufacturing and other industrial operations down a road of smart automation. This is fundamentally changing the way products are made and services delivered.

With such a momentous shift taking place – some argue it’s as significant as the invention of the production line itself – it’s not surprising it’s getting so much attention. What isn’t getting quite the same attention is how this is all being made possible. And if you dig a little deeper and look at the way the sensors, gateways and controllers that make up the industrial IoT are being designed and manufactured, you’ll find there’s an equally significant change underway.

The traditional complexity of IoT design

These IoT nodes would traditionally have been designed and built from scratch, with engineers selecting a microprocessor or microcontroller, memory, connectivity and other components, then combining them on a circuit board. While this approach provides enormous flexibility to create exactly the product you want, it also brings complexity.

Unexpected RF interference, for example, is a common issue. So is the risk that one of your suppliers changes or discontinues their component, leaving you with the headache of finding, integrating and testing a replacement – followed potentially by having to re-certify. And if something in your design doesn’t work the way you expected, the bespoke nature of your creation means you may struggle to find anyone who can help.

All of this pushes up the cost, risk and testing time of bespoke designs. Consequently, your end product will take longer to get to market, and won’t necessarily be as competitively priced as you’d like.

These issues help explain the shift we’re seeing, with new and experienced designers alike increasingly choosing to build products around off-the-shelf single-board computers (SBCs).

The rise of the single-board computer

SBCs have been around since the 1970s, but have risen to prominence in recent years thanks to the success of Arduino, BeagleBoard and, perhaps most famously, Raspberry Pi.

So what’s driving their increased popularity, particularly when it comes to equipment destined for the IoT?

Wide range of products

Firstly, there’s plenty of choice. Take processing power, for example. You can now get affordable SBCs with meaty processors and even some with GPUs or FPGAs. This enables remote nodes to carry out complex calculations in situ, without the cost or latency of sending data to an external processor or the cloud. Equally, if power budgets are limited, as they often are in remote nodes, there are plenty of SBCs with highly energy-efficient processors.

Designers have plenty of choice when selecting an appropriate off-the-shelf board for their needs.

Reduced complexity

SBCs also remove a large portion of the design and testing complexity we touched on above, because you’re not completely reinventing the wheel. Instead, you’ve got a proven product that will have been rigorously tested, probably to a much greater extent than would be feasible for a bespoke design delivered under time pressure.

Let’s look briefly at what this reduced complexity means in practice.

Firstly, single-board computers cut the number of connectors in your design. This enables you to deliver a smaller and more robust product than you’d be able to achieve using discrete components.

Second, using an integrated SBC will result in a quicker design cycle. Testing will also be faster and any required certification, such as required for wireless compliance, potentially less challenging.

As a result, SBCs directly drive down cost and time-to-market of your product and, by extension, your customers’ products, without compromising on quality.

The other big benefit of SBCs is that many use open source software and have big support communities. This means that you as a designer – whether you’re an electronics enthusiast or a professional IoT engineer – have easy access to everything from reference designs to forums where you can discuss ideas and challenges with others.

A selection of single-board computers

Given these advantages, it’s little surprise that SBCs are becoming an ever-more popular choice, particularly as demand for low-cost connected industrial devices grows.

As we touched on earlier, you’ve got plenty of choice when it comes to selecting a SBC for your product. Let’s look at some options.

Raspberry Pi 3 Model B

A popular choice is the Raspberry Pi 3 Model B, which doubles the amount of RAM found in its Pi 2 predecessor and comes with an ARMv8 processor running at up to 1.2 GHz. It also has 40-pin GPIO header, audio and video outputs and, importantly for IIoT use, incorporates Wi-Fi and Bluetooth Low Energy (BLE) alongside 10/100 Ethernet. This gives you a fully connected solution, without needing external kit.

Figure 1: Raspberry Pi 3

BeagleBone Black

TheBeagleBone Black is another option, with its ARM Cortex-A8-based processor running at 1 GHz and 512 MB RAM. It includes 4 GB of on-board storage, a NEON floating-point accelerator and two programmable real-time unit (PRU) 32-bit microcontrollers. It also has a pair of 46-pin GPIO headers. The BeagleBone Black comes in two variants: one with a 10/100 Ethernet connector, the other with Wi-Fi and Bluetooth 4.1 (including BLE).

PocketBeagle

If you need something altogether more compact, BeagleBoard makes the 55 x 35 x 5 mm PocketBeagle. This SBC is also low-priced (around $30), and packs in a 1 GHz ARM Cortex-A8, 512 MB of RAM, an energy-efficient ARM Cortex-M3 and a pair of 200 MHz PRUs. The SBC also has 72 expansion pin headers with battery and power I/Os, USB, eight analogue inputs and 44 digital I/Os.

Figure 2: PocketBeagle

SparkFun Onion Omega2+ IoT Computer

Designed specifically for the IoT, the Onion Omega2+ costs just $9, yet packs in everything an IoT designer needs to create connected equipment. Its 580 MHz MIPS processor is supported by 128 MB RAM and 32 MB flash storage. There’s also onboard Wi-Fi, pins for USB and Ethernet, plus 12 GPIOs that support the SPI, UART and I2C protocols.

Its makers liken to Omega2+ to a Raspberry Pi, but note a couple of key design choices they made with the IoT in mind. Firstly, in the interests of energy-efficiency, the processor in the Omega2+ is less powerful than what you’ll find in most Raspberry Pi models. Equally, while it can drive small displays, the Omega2+ can’t be hooked up to a computer screen or television. It also won’t run a graphical Linux desktop operating system. That said, it comes with on-board storage and the operating system pre-installed, while Onion claims its SBC uses less power than a Raspberry PI.

Figure 3: Onion Omega2+

Arduino Industrial 101

Lastly, the Arduino Industrial 101 evaluation board is another designed for the IoT. With a 400 MHz MIPS processor and a 16 MHz ATmega32u4 microcontroller, this board also has Wi-Fi, 64 MB RAM and 16 MB flash storage.

Time to try a single-board computer

With a compelling list of benefits and plenty of choice for IoT product designers, now is the ideal time to switch from creating bespoke equipment, to using one of the many off-the-shelf single-board computers available today. Whatever the use case for your product, an SBC will nearly always help you get your kit in the hands of customers more quickly and at lower cost.

www.mouser.co.uk

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