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The Internet of Computers

COLIN MCCRACKEN

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What do the following things have in common: self-driving car technology, video streaming of World Cup soccer/football, global warming sensor measurements, UAV photo capturing and remote household appliance control? Hint—it’s not a government surveillance program involving metadata collection. Okay, at least that’s not the answer we were looking for.

The Internet of Things (IoT) has given renewed enthusiasm to developers and lucrative valuations to Wall Street, as well as a fresh facelift to aging computer board alliance programs. Although vast database-driven Web pages are full of new and near-EOL boards alike, the latest certification programs create real value to OEMs by bringing together fully tested hardware and software.

It’s not a new idea for every device and gadget under the sun to have its own unique address. It has taken ten, even twenty years for early concepts to finally take hold on the massive scale that is now underway. Previous obstacles like size and power reduction are being overcome at an unprecedented pace.

Where does desktop PC technology fit into the IoT realm? Small form factor (SFF) computer boards are already widely used in mobile and line powered embedded systems. Yes, “embedded.” The term has not actually reached obsolescence in this IoT era. The “15 billion embedded devices by 2020” target has been simply re-labeled as “30 billion devices on the IoT by 2020.” Or perhaps re-focused. After all, these are not all French-style smart cards and cell phones. There are quite a large number of tiny systems with unique requirements that cannot be met with a one-CPU-fits-all approach. Nor a single Internet gateway. Nor a single wireless (radio) interface.

When all you have is a hammer, everything looks like a nail. SFF x86 board and chip vendors apply 64-bit multicore processors with huge caches and fast interfaces like PCI Express, SATA, USB and Wi-Fi to the myriad of tiny micro-power sensors and mesh networks. Even if each processor core only draws 2 watts when lightly loaded, the I/O and memory interfaces burn much more power than necessary to accomplish edge tasks. Wi-Fi is not the best fit for a large number of endpoints that hardly need to update more than a few times a second, if even that.

Working backward from the endpoint perspective, one can calculate the bandwidth each device needs in both directions. Often in the broader IoT picture, sensors sip from a faucet. By comparison, edge routers and access points drink from a fat pipe while core routers and Big Data servers and Cloud storage devices gulp from a fire hose. Serial ports, SPI bus and I2C are examples of interfaces that not only match the data rates, but are also easy to attach to using a CPLD or small FPGA, or even bit-banging with GPIOs that microcontrollers have. In many cases, microcontrollers and 32-bit ARM SoCs have built-in UARTs, USARTs and SPI ports that run faster, with FIFOs that don’t tie up the micro. Some low-cost, low-power A-to-D chips have direct SPI interfaces, obviating the need for an FPGA at all. Similarly, an onboard SSD chip or flash in the microcontroller itself is more optimized than mSATA, M.2 or m-anything else.

The x86 processor community killed off serial ports when USB took over desktop peripherals. Fortunately, the embedded market does have influence at the lowest end of modern x86 SoCs, where serial ports have re-emerged. It’s usually applications like car computers that have the unit volumes to buy influence. Don’t get your hopes up too much when you see the SPI port on the datasheet or pinout, because that is usually reserved for firmware.

So the IoT isn’t going to become the IoC (Computers) any time soon, despite all best efforts. You have to Sprechen Sie I/O first. Then a well-tested small Linux or RTOS, or no OS is important to the dialog.

There’s no getting around it, though. PC technology has become quite embedded into the everyday life of the developer community. Even though they are comparatively large, bulky and costly, such off-the-shelf building blocks are convenient in a world where time-to-market translates into market share. Even if not cost-optimized, x86 systems will ride the wave rather than miss the boat, clear out to the access points and even in some edge systems where data crunching is more efficient to do there. Where there’s an I/O bridge and accompanying device driver, there’s a way. But the lowest power edge devices with IP interfaces will be captured by ARM’s iron hand.