Enabling the Development of Wireless Applications for ZigBee Novices
Manufacture seeks to provide ‘total solution’ of hardware, firmware, and support to decode ZigBee for relative novices of RF and software
As a wide range of private companies and other standards-promulgating bodies compete to establish their respective wireless protocols as ‘the default’ for a given niche (e.g. ANT vs. Bluetooth® vs. Nike+ in the WPAN space, EnOcean vs. Philips in the Energy Harvesting space, and so on) -- there is little question that the ZigBee® Standard has successfully moved beyond its origins of promoting its protocol for adoption by power utilities in Automated Meter Reading Applications to emerge as a heavyweight in any number of Internet of Things (IOT) segments where a low-power, multi-node, self-healing mesh network on an IEEE-supported backbone is suitable.
Figure 1: AIR Solution for ZigBee circle
Indeed, the official ZigBee Alliance website (www.zigbee.org) documents the organization’s own dominance in this regard with a number of not unpersuasive third party citations. Among these, Allen Nogee, Research Director for In-Stat, is quoted as saying “ZigBee has been considered the front-running short range connectivity option for smart grid since its inception, and has maintained its position so far. While the number of ZigBee clients in homes to date is relatively small, In-Stat believes that ZigBee will maintain its dominance.” ABI Research states “ZigBee comprised roughly 40% of the 2010 IEEE 802.15.4 chipset shipments and will grow to comprise nearly 55% of 2016 IEEE 802.15.4 chipset shipments.” And IMS Research goes on record with the prediction that “Over 1.1 billion IEEE 802.15.4 ICs are forecast to be shipped in the period 2009-2015. Of these, over 85% will use ZigBee or ZigBee-RF4CE certified software stacks.”
While there is little doubt, then, as to the attractiveness of the ZigBee Standard – as evidenced by its speedy adoption by OEMs seeking to supply any number of ZigBee compliant wireless devices, appliances, and equipment types for the smart grid, smart home, and smart building markets – it must be admitted that developing ZigBee-oriented applications can be appear quite daunting for design engineers not particularly well versed in RF communication or the intricacies and peculiarities of software/code development.
To its credit, the ZigBee Alliance has worked tirelessly to bridge the knowledge gap for its more uninitiated customers, with the introduction of easy-to-deploy ZigBee “Profiles” specifically designed to provide an easier market entry for high-interest, time-to-market sensitive segments like audio/visual remote controls, 3D active glasses, lighting control systems, among others.
Parallel to such initiatives by the ZigBee Alliance as a whole, however, one of the Alliance’s member companies – Anaren, Inc. (Syracuse, NY) -- has been taking its own steps to ease and even accelerate the wireless-for-ZigBee development process. With the introduction of what it refers to as a “total solution” centered on its family of Anaren Integrated Radio (AIR) modules for ZigBee Standard applications [see figure 1], the approach bundles the company’s AIR module, with a unique firmware package, development kits, and intangibles like no-cost applications support and end-products for the OEM that are free of licensing and recurring engineering costs.
Taking some of the ‘hard’ out of hardware for the ZigBee Standard
Figure 2: CC2530-based AIR modules (embedded antenna & connectorized in one image)
In addition to the myriad choices an OEM must make when ‘going wireless’ – chief among them being the selection of the protocol that strikes the best balance between often divergent goals, such as maximizing range, saving power, or ensuring signal robustness – every manufacturer must also determine if it is advisable to develop its own radio by sourcing and coordinating discrete components or to opt for one of several pre-packaged radio modules on the market.
If ZigBee proves to be the protocol of choice – and if the OEM in question lacks super-high sales volumes or in-house RF expertise that would otherwise suggest the discreet radio route – Anaren’s A2530xR24xxx AIR module can eliminate some of the guesswork and hard work for mid- to small OEMs. First, the module is based on Texas Instruments’ well-vetted CC2530 SOC, which in turn runs TI’s software stack for ZigBee contexts, called Z-Stack. [See figure 2.] With Z-Stack in place and representing what are often referred to as the Physical/MAC layers (based on the IEEE 802.15.4 standard) and the basic Network communication layers atop them -- the OEM is a good way along the path toward an end-product that is suitable for communication within a ZigBee-based network. (We will address the application-specific aspect of the firmware, in the next section.)
Beyond housing TI’s Z-Stack equipped CC2530 SOC, Anaren’s AIR module offers several other notable advantages, ranging from low power consumption of under 150mA in full output mode (which can be critical in 1000+ node networks where power for each node may not be readily available); a compact, SMT package measuring a mere 11 x 19 x 2.5mm; and both pre-certification to applicable FCC/IC “intentional radiator” standards and compliance with analogous ETSI standards in Europe. It also doesn’t hurt that the price tag per module at distribution can be expected to be under $15, in quantities above 10,000.
Having addressed the hardware issue with its all-in-one AIR module, Anaren next addresses the even more challenging aspect of the ZigBee arena: development and implementation of the firmware’s application layers.
Figure 3: Firmware stack (“layered cake”) illustration showing Z-Stack (including its coverage of ZigBee’s basic layers) and AIR ZNP
With Z-Stack’s foundational Phy, Mac, and Network layers in place, the OEM must next develop and deploy its own application-specific, yet still ZigBee-compliant code. To accomplish this, one must first identify, extract, deploy, and test the right bits of code from the ZigBee library. However, the architecture of ZigBee can take weeks to fully understand, before the process of functional block extraction can take place.
Here again, Anaren can offer some valuable assistance to the ZigBee neophyte, this time in the form of its AIR-ZNP tool, which isolates the Z-Stack from the customer’s application via an external microcontroller/host processer and communicates through a simple interface. Anaren’s AIR-ZNP tool is comprised of an Application Programming Interface (API) that has been specifically designed to ease the job – and 30+ commonly used code examples [see Figure 3] that essentially ‘snap’ together, building-block style, to form an impressive array of applications. The result is a much compressed……fewer days and even weeks from the ZigBee learning and development process.
With both the hardware and firmware portions of the ZigBee equation now having been addressed, Anaren goes a step further – providing a unique development tool that enables the ZigBee novice to establish, and then begin customizing, a simple ZigBee network in just a few minutes.
Enter the BoosterPack development kit
Figure 4: BoosterPack kit
Just as there is a choice of modules on the market to assist in complying with the ZigBee Standard, there are is a range, albeit modest, of development kits to help an OEM bring hardware and software together with the goal of creating a finished, reproducible, and commercially viable end-product. Many of these kits are quite costly (pricing out at upwards of $1,000), however. While more economical entries tend to skimp on flexibility, capability, or taking time to provide much-needed context or an educational, step-by-step approach.
Here again, Anaren saw an opportunity to smooth the road for OEM engineers interested in concurrently testing a ZigBee ready module and developing a software application guaranteed to run on said hardware. Enter the company’s new CC2530 BoosterPack kit.
Snapped onto either Texas Instruments’ MSP430™ or Stellaris® LaunchPads, the three AIR module-equipped BoosterPacks included in the kit enable the user to establish and begin testing a simple ZigBee wireless network in under five minutes. (In most instances, two of the BoosterPacks will be powered by standard USBs, while the third can be mobile or remote, thanks to a battery pack also included in this $99 kit.)
On startup, each of the three BoosterPacks has a pre-assigned, but changeable, role in the network (i.e. Coordinator, Router, and End Point) – and each is pre-flashed to run a basic ZigBee network ‘demo’ included with the kit. With the demo up and running, the user can next customize the demo or build an all-new application using the 30+ code examples provided.
Anyone new to software and RF development can be expected to require robust informational support, and that requirement is only compounded when the equation includes accounting for the relatively complex animal that is ZigBee.
Surrounding its AIR module and AIR-ZNP firmware - and provided via no additional costs (including licensing or consulting agreements) – Anaren’s AIR Support for ZigBee solution [see Figure 4] attempts to provide this backstop of assistance for the uninitiated. The solution begins with an NDA-protected, initial consultation intended to ensure the OEM’s has selected the best protocol given its end-products performance objectives and the company’s longer-term strategic goals. Next comes Development and Applications Stages, which include kits and firmware tools outline earlier. And finally, the company offers Production Stage assistance with working the actually AIR module into the OEM’s production routine – accounting for everything from board layout, to soldering guidance, to packaging.
For the practiced RF and software expert, and depending on the application, the ZigBee Standard is a proven, advantageous, and doable path. For those less versed in the ZigBee discipline, the modularized hardware, intuitive firmware, and inexpensive development kit collectively referred to as Anaren’s AIR Support for ZigBee solution may be worth a closer look.
December 11, 2012