Quickie ZigBee Application Kit from Rabbit!

needed skill to

Hardly. Zigbee is one of those license portfolios^H^H^H^H^H^H^Hvaluable technological innovations you approach, see if you can use any parts, then back away again.

I know they posit it as being the best thing since sliced cheese and the technology that will mesh us all, but the cup hasn't reached the lip yet by a long, long way.

The strongest thing you can say with a straight face is that by this time next year, there may be some more brochures listing Zigbee as a bullet point. It will CERTAINLY not be an essential survival skill.

needed skill to

at least it's cheap, anytime you see a product that is bluetooth compatible you know it has a hefty pricetag on it.

Hmm, maybe. Bill's effusive postings gushing over the extreme purchase-worthiness of whatever flavor of the month just annoy me somewhat.

needed skill to

Bingo! The importance of ZigBee is also that it is not only (usually) inexpensive, but most importantly it is very low power. And the adoption rate I'm seeing in the market is tremendous because it is serving an unaddressed market.

In the field of wireless sensors alone, ZigBee is becoming the dominant wireless technologies because with just a small sensor hooked up to a ZigBee node with a common battery, you can have a battery life of over a year.

No, it's not sexy, and it's not high speed, and it's not faster than a speeding bullet. But yeah, it's growing faster than Bluetooth ever did.

Regards,

Bill Giovino Executive Editor

I'm sorry to see you write that. In the future, I will try to be more on-point.

Regards,

Bill Giovino Executive Editor

Hello Bill,

needed

To be honest, I'd have some doubts there just as Lewin does.

inexpensive, but

market is

wireless

a common

My old wireless thermometer has a battery life of over two years and it doesn't use Zigbee ;-)

speeding bullet.

Any hard data to back up that claim? I mean, not prognostic but proven sales numbers?

--
Regards, Joerg

http://www.analogconsultants.com

needed

inexpensive, but

Well, it's only low power when it's in beacon mode, it takes 20-40 mA to transmit/receive, and looking at the datarates it's not any better (mA/datarate) then bluetooth.

Agreed.

*Exactly*. I looked seriously at ZigBee for a few product designs and backed away from it, quickly. For any *sustained* data rates, it holds no advantages over BT (design an intercom system using Zigbee and look at the power consumption :> ). And, it doesn't "play well with others" (zigbee-enabled printer? zigbee-enabled cell phone?? zigbee-enabled keyboard?)

As with everything, "that depends".

Have you analyzed "price per transmitted data bit"? Or, "price per WHr?

"Any time you see a product that is CARBIDE TIPPED you know it has a hefty price tag on it". (and, those products that are NOT "carbide tipped" don't last long cutting through masonry! ;> )

Horses for coarses.

Yeah, and I've never replaced the battery in my wireless garage door opener in the 6 years since the purchase of the garage door... Amazing how devices that don't transmit any data (i.e. *do* any electrical "work") seem to last SO LONG on a single battery! ;-)

Perhaps in terms of *nodes*, but not in terms of "deployments". E.g., you may opt to use zigbee for a security system, intrusion detection, HVAC control, etc. -- in which case, you might easily have 1000 nodes in a single site (e.g., a hotel).

But, the hundreds of *guests* staying in that hotel at any given instant probably ALL own a BT-enabled phone -- or, soon

*will*!

Amusing thought: book a room in said hotel and set up a zigbee master waking up all the nodes within "earshot" every second or so. And chuckle to think of the maintenance staff scratching their heads wondering why all of the zigbee devices in "the east wing" had batteries die twice as fast as those in the other parts of the hotel :>

inexpensive, but

Exactly. Zigbee addresses the very low data rate market. Ideal (?) for something like HvAC control in a large facility. Or, energy management. Where the cost of *wiring* far exceeds the cost of the device (assuming you can't come up with other clever solutions to eliminate that wiring) -- yet the device's communicaions requirements are essentally miniscule..

Hello Don,

Tell me about it. I managed to gum up one of these because the wood I bought wasn't as well dried as advertised. Stood there in a plume of blue smoke and almost cussed. Spent at least 15 minutes to expose the carbide tips again because the blade had cost a bundle.

Au contraire. This thermometer relays a reading every 30 seconds and runs on a couple of AAA alkalines for two years, even when it's 25F. The receiver is constantly polling for outdoor stations. That one also runs on batteries which don't need to be changed over a two year time frame.

Then there is the atomic clock which operated five (!) years on the first set of two AA batteries.

I am afraid there will be an unpleasant awakening when users realize that while the node hopping feature increases network reliablity it might slurp batteries like popcorn.

--
Regards, Joerg

http://www.analogconsultants.com

That is not the design space for ZigBee. It is low data rate, low battery life. It is one, if not two, orders of magnitude lower power usage, with the restriction that it is orders of magnitude lower data rate.

For me, price per trasmitted bit for both the radio and the batteries to drive it are important.

Not that ZigBee is the only thing in this space. ANT is also here, and Nokie just announced a new competitor.

Duh, but ZigBee is designed for usage patterns far higher than a garage door opener.

That said, So far, ZigBee seems to have no legs

I don't see those as good matches, for HVAC, you run wires or pneumatic controls. The ZigBee Allaince folks brag about using ZigBee to replace X10. no legs there either.

BT works for phones, people are used to recharging them. Today's bluetooth is far too power hungry for sensor networks, altho people are trying.

A future Bluetooth could work, but that is futures.

That should not be a problem with a properly specified network. But software has been known to have bugs.

--
Pat

Don wrote: at least it's cheap, anytime you see a product that is bluetooth

But I don't want and don't need a carbide tipped cutting tool, that was my point, Zigbee is cheap, small (4x4mm), and some come integrated with a 8051 processor, at continuous modes it has a decent rates of 250 Kbps

Z-Wave seems to be a better solution, though most of the big boys are jumping on the Zigbee bandwagon.

That was my point -- "faulting" BT because it is "power hungry" is equivalent to faulting Zigbee for being *slow*, etc.

As they are with me. But, I have *lots* of bits to transmit and Zigbee falls off the curve quickly.

Sure. The example illustrates that battery life is related to "work done" (data transmitted)

For *new* HVAC installations, yes. But, the cost of REwiring a school, hotel, hospital, residential care facility, etc. pays for a wireless solution by a couple of orders of magnitude. In many of these environments, self-contained heating/cooling units are sprinkled liberally around the facility -- needing only *power* (i.e. often the thermostat is part of the unit itself -- to eliminate control wiring).

Adding controls to allow effective load management, energy control, etc. for the price of a wireless node w/ microcontroller is a *huge* win over asking a licensed electrician to string wires (to where??).

I suppose it's only a matter of time before some of these sites are "hacked"

Hence the "horses for coarses" comment. Zigbee (BT, etc.) is not a panacea. It fits *a* market niche. In *my* case, BT fits my niche while Zigbee couldn't approach it on power, data rate, etc.

"Horses for coarses"

Ideal for a tiny, "simple" sensor or actuator. Where the "brains" of the application can reside elsewhere. (assuming that sensor or actuator does not need any clever recovery algorithms to handle loss of communication, etc. -- a problem not unique to zigbee but, rather, inherent in wireless designs and often not well handled)

Actually, this is precisely where you WON'T use ZigBee. The profits in wireless security are in the sensors. There is a strong disincentive for security system vendors to commoditize those sensors, and the most they would do with zigbee is pick and choose some particular design aspects, then add a lot of product differentiation and proprietary stuff. Anyway, wireless security and fire safety have a lot of special regulatory requirements and specific customer expectations, and ZigBee doesn't meet these elegantly.

Zigbee's "rational" target market is home automation. Look at the staggering penetration of technologies like X10 (yes I'm being very sarcastic) and you can see just what untold wealth is waiting there.

I repeat my retort to Bill that saying "next year you'll need it on your resume" is mere breathless marketing puffery. Next week/month/whatever he'll have a new group of advertisers pimping something else and ZigBee will be a distant memory.

Hello Lewin,

IMHO X10 failed to penetrate because it is not reliable. We have X10 and I would never use it for anything critical. Insteon is too young to say much about it. Whether Zigbee lives up to the task remains to be seen. The issues I see coming are battery life and lacking RF range in some situations. Just trying to get any decent signal into our garage or the room next to it can be (and has been) frustrating. Even the cell phone often hangs up and we can literally see the tower.

--
Regards, Joerg

http://www.analogconsultants.com

More than that: the functionality it provides simply not useful to most people. The demand for remote-controlled power outlets is simply not enormous. People do not need to have remote-controlled drapes and light dimmers. Many (majority?) of houses do not even have any dimmable lights.

X10 is a [poorly-worded] answer looking for a question.

ZigBee is a more elegantly crafted answer, also looking for a question.

Hello Lewin,

Have to disagree here. To us as a rather typical household it has proven to be very useful. A few examples:

Alarm clock goes off, with us wanting to snatch just five more minutes of shut-eye. But, coffee needs to be ready by then or we won't have time. Press the magic button, a relay clicks in the kitchen, sleep those five mins more and the coffee will be ready anyway.

Working in the yard, got late and dark but wife still wants to play a game of table tennis (I don't because I always lose but I have to). Push another magic button and, voila, it's not dark anymore where the table is.

Forgot to turn on or off the driveway lights? Can't happen, X10 has already done that. From downstairs this would otherwise be a long trek towards the other end of the house. Plus when neighbors want to come by unexpected they don't have to stumble up a dark driveway.

What's that light that's still on? Who forgot to turn it off? No need to hop out of bed and go into the cold basement in the pajamas. Press a button, done.

And so on. Anyways, nearly every time visitors see this stuff they ask me whether I can install it in their homes. Which I politely decline because X10 is not reliable enough for my taste and you almost have to be an engineer to diagnose problems.

IMHO X10 did not make it for two reasons. One is technical issues. Two is lack of advertising. The latter is, in part, caused by a lack of interest by electricians because they fear too many after-sale issues.

Elegant, yes. But will it work in a house? Did the standards guys think about the fact that some of the insulating wool in walls and ceilings is aluminum backed?

For home automation in retrofit (and it's nearly always going to be a retrofit situation) I believe comms need to run two-pronged. Powerline plus RF. Not either-or. The only other scheme I see doing that is Insteon. A bit on the pricey side but who knows, maybe they make it into the big stores. IMHO a strong presence in the big box HW stores is the only way to make a market in home improvement.

--
Regards, Joerg

http://www.analogconsultants.com