The Internet Of Things

The momentum building behind the Internet of Things – an overview

Suddenly the world is becoming connected. Trillions of sensors are starting to be connected to billions of controllers and millions of gateways, all pumping data around the globe via the Internet.

This Internet of Things (IoT) is enabled by a set of capabilities, from low power wireless protocols to high performance, low power microcontrollers. But there are many layers to the implementation of the networks, from the sensor nodes up to the gateways and then to the data servers that can handle all this ‘big data’, and all kept secure. All this is looking to link up devices and lighting in homes, the grids for power and water, cars and transportation to provide a more intelligent, responsive, controllable world.

At the heart of these developments are low power wireless links and microcontrollers. The latest Gecko microcontrollers from Silicon Labs for example are using specially developed low power modes so that the controllers can just wait for a signal from the sensors before starting up, sending the data and shutting down again. These are being optimised for smart grid power applications with batteries that run from 3.6V and run for ten to 20 years, as well as for sensor networks. These are taking the power consumption so low that they can now be powered from solar cells and even from the RF or thermal energy in the surrounding environment so that batteries or a power lead are no longer necessary.

But these need low power links as well, and various protocols are being used for IoT. The 2.4GHz ZigBee mesh network has been widely adopted in machine-to-machine (M2M) applications and allows nodes to be easily added to the network, linking to a gateway device for low data rate (250Kbit/s) links from suppliers such as Atmel and Texas Instruments.

The latest version, ZigBee IP, moves to the IPv6 standard and allows the sensor nodes to be accessed directly from the Internet, allowing many more devices to be controlled. The Green Power version of ZigBee allows devices to be easily powered by energy harvesting.

But there is competition on several fronts. Low power versions of WiFi are using lower data rates and quick bursts of data to provide dramatically longer battery life with the low cost that comes from high volume shipments. Similarly the Bluetooth Low Energy (LE) in the latest Bluetooth 4.0 version of the standard allows very low power for connections. While this has initially seen traction in consumer devices driving up volume and driving down cost, there is increasing interest for IoT applications.

All this interest has also led to new technologies such as the Weightless protocol that has been developed specifically for these IoT applications.

The Special Interest group behind Weightless is seeing the first silicon devices taping out at the moment with volume silicon in Q2 2014 from founding company Neul. The first modules measure 35mm x 45mm and will cost around $12 at the start, falling to $7 in 2015 and 24mm x 20mm modules costing $4 or less in 2016.Weightless development kits are scheduled for launch to early access customers in Q2 2014.

The base station, NeulNET 2510 will sample in the first quarter of 2014 with pre-commercial availability in Q2 2014 and cost "tens of dollars" per month to lease for networks in the UK and the US, according to Professor William Webb, CEO of Weightless SIG.

Figure 1: The Weightless protocol has been developed specifically for the Internet of Things

As Weightless demonstrates, these sensors and controllers need to connect up to a gateway, and the big chip companies are all positioning themselves for this market. With gateways in mind, Texas Instruments has integrated both the MAC and physical interfaces for Ethernet onto an ARM-based microcontroller to simplify the design.

The latest devices are the first ARM Cortex-M4-based controllers with Ethernet MAC+PHY as well as on-chip data protection and LCD controller to save significant board space and enable connected applications such as home/building automation gateways, connected human-machine interface (HMI), networked sensor gateways, security access systems and programmable logic controllers. Integrated CAN and USB provide high-speed connectivity, allowing the creation of seamless gateway solutions while lighting, sensing, motion, display and switching use sensor aggregation through 10 I2C ports, two fast, accurate 12-bit analogue-to-digital converters (ADCs), two quadrature encoder inputs, three on-chip comparators, external peripheral interface, as well as advanced pulse-width modulation (PWM) outputs.

Software is a key element for IoT, and Wind River has developed a complete software development environment based on Intel architecture processors. The platform, due to be available early in 2014, will provide ready-to-use components to secure, manage, and connect IoT gateways.

The software adds gateway security as well as Lua, Java, and OSGi application environments to enable portable, scalable, and reusable application development on both resource-constrained and full-featured devices as well as native support for WiFi, Bluetooth, ZigBee and other short-range wireless protocols.

In the meantime other semiconductor vendors are teaming up with software suppliers to provide complete solutions across the IoT.

Working with ARM and Oracle, Freescale Semiconductor has developed a secure, ‘one box’ platform that combines end-to-end software with converged hierarchical smart gateways to establish a common, open framework for secured IoT service delivery and management.

Based on Freescale’s Kinetis microcontrollers, i.MX applications processors or QorIQ communications processors, the platform runs Oracle’s Java software and incorporates ARM’s Sensinode software, which securely connects large numbers of low-power edge node devices using other wireless protocols such as 6LoWPAN, CoAP and OMA Lightweight M2M protocols.

Freescale, ARM and Oracle are also working to streamline the development of nodes under the ARM mbed project. This would allow the native hardware abstraction layer (HAL) at ARM mbed to run Oracle Java ME Embedded software on ARM-based Freescale Kinetis microcontrollers.

The cloud can also be used to support all these sensor nodes. Xively, a subsidiary of remote access software company LogMeIn, developed the first public cloud platform for the commercial Internet of Things (IoT), and is now working with Linear Technology to accelerate the availability of ultra-low power cloud-connected products. By integrating Linear’s Dust Networks wireless sensors with Xively’s Cloud Services, the companies can give developers and OEMs a highly cost-effective, end-to-end IoT solution that works from initial prototyping and validation through wide-scale commercial deployment and management.

The ARM Cortex-M3-based wireless sensors are built for IP compatibility and use the 6LoWPAN and 802.15.4e standards to provide >99.999% data reliability and >10 year battery life, making it practical to deploy wireless sensor networks in the most challenging environments. A starter kit includes sample application code that allows a registered Xively user to simply connect the DC9000 kit to a web-connected computer, enabling the IP sensor network to automatically be registered as a Xively “product,” and the nodes and sensors to securely send data to the user’s Xively cloud as “devices.”

All of this highlights the momentum building behind the Internet of Things. Not only are there sensors and devices available, but also the software environments, end-to-end implementations and application development are now starting to emerge. This will stimulate more development and more volume roll-outs, driving down the cost. Most of the devices out in the market are increasingly integrated and run multiple protocols, giving the system designer more flexibility in choosing the right solution at the right cost points.