Feeds

Tiny tech ZigBee harnesses puny power of the press

Batteries? Where we're going we don't need batteries

Bridging the IT gap between rising business demands and ageing tools

The ZigBee Alliance - which looks after the low-power radio comms standard - has now introduced wireless communications that are powered by the act of pressing a key.

Green Power is an extension to the Zigbee protocol that allows switches and sensors to operate from tiny amounts of power - such as the power generated by the physical act of flicking the switch, or from tiny solar cells out of direct sunshine. It offers the promise of a wireless future which doesn't shudder to a halt when the battery runs out.

Energy Harvesting, as the technique is known, isn't new, but allowing a device powered by the technique to interact with an existing mesh standard is - and this is what Zigbee Green power promises.

The standard uses a reduced-size packet - around 21 bytes compared to the usual 127 bytes allowed by the Zigbee standard. The diminutive packet can be sent several times using the power harvested by a piezoelectric* element behind a light switch, thus allowing a device to interact with the Zigbee mesh network without needing any battery or any other source of power.**

That's just for sending, and only works when the switch and the sink (the thing it controls) are within range of each other. To take advantage of Zigbee's self-forming mesh, and receive data, the Green Power element needs to have a proxy presence within the mesh to which it can connect directly.

Illustration of how the ZigBee Green Power device accesses the sink through proxies - via ZigBee.org

The proxy needs proper power, a battery at least, as Zigbee will consume 20 millijoules an hour. That's just a fraction of that consumed by competing protocols but it's still significant - the Zigbee Alliance has pretty pictures showing Wi-Fi consumption as the Eiffel tower, Zigbee as a small boy standing beside it and Green Power as the balloon he's carrying, showing how consumption compares.

Zigbee's ability to automatically mesh is marvellous, and should be a killer feature though the technology has been slow to spread thanks to interoperability hiccups and competition from the only marginally more proprietary Z-Wave standard, which can also mesh itself to extend coverage.

Devices using Energy Harvesting techniques have hitherto been limited to proprietary technologies such as those sold by EnOcean (embodied into ISO/IEC 14543-3-10), which remain incompatible with Zigbee's Green Power standard but provide another alternative for those who really hate batteries. ®

* Generating energy from pressure

** Existing radio switches use tiny batteries, like the 23A, which last a few years in daily use (in the experience of your correspondent) but can be irritating when they run out and are clearly unsuitable for mission-critical applications.

The Essential Guide to IT Transformation

More from The Register

next story
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
Bring back error correction, say Danish 'net boffins
We don't need no steenkin' TCP/IP retransmission and the congestion it causes
NBN Co adds apartments to FTTP rollout
Commercial trial locations to go live in September
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
Samsung Z Tizen OS mobe is post-phoned – this time for good?
Russian launch for Sammy's non-droid knocked back
Telstra to KILL 2G network by end of 2016
GSM now stands for Grave-Seeking-Mobile network
Seeking LTE expert to insert small cells into BT customers' places
Is this the first step to a FON-a-like 4G network?
What FTC lawsuit? T-Mobile US touts 10GB, $100 family-of-4 plan
Folks 'could use that money for more important things' says CEO Legere
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.