Re: Open Source

[Karl Denninger <karl@xxxxxxxxxxxxx>]

GRHSTechnologies@xxxxxxxxx wrote:
> On Feb 13, 10:17 am, Karl Denninger <k...@xxxxxxxxxxxxx> wrote:
>> BATTERY operated devices eh?
>>
>> Ok, point taken.  How about all the LINE POWERED devices?  You know,
>> like wall switches and outlets?
>
> You do not understand - every Z-Wave node is a repeater for the
> network, so the act of simply placing a Z-Wave node/device in the
> path, you have thus extended the network range.  So if your dock was
> over 100' away, you could place any Z-Wave device 60-70' away from the
> house toward the dock, and now the devices (line powered switches and
> outlets) in the dock area would be controllable.

That is not true.

Battery operated devices that are sleeping do not operate as repeaters.
  Specifically, PIRs do not.

Line-powered devices do, but line powered devices don't need to be
power-limited to 30'.

The point here is that 30' is woefully inadequate and also somewhat
optimistic in many circumstances (especially if the switch is inside and
the next "node" is beyond a brick or other exterior facing, with several
worse than brick (e.g. aluminum siding is a quite-effective shield at
900Mhz!)

>> They certainly don't need to be restricted to THIRTY FEET of range in a typical home, right?
>
> Right - the nominal range is 100', and your mileage will vary based
> upon metal obstructions in the walls, etc.  In most homes, there are
> zero or just a few nodes that cannot communicate directly with every
> other node and must route through another one.  However, without
> routing the round trip time is around 80ms compared to X-10's 666ms
> for one way, so even if it routes and takes a little longer, it is
> still by far better than most if not all powerline technologies.

Correct; Zwave inside the house works fine.  The problems arise when you
want to do something like have a sensor in the garage (without a node in
the middle) - that one is easily solved, but the dock or Gazebo is
another matter.


>> A Wifi Repeater at the dock for the explicit purpose of repeating ZWave?
>> That's called a HACK.
>
> Not if it is for an Ethernet Z-Wave interface.  If you wanted to use a
> laptop computer with a WiFi adapter at the end of your dock, you might
> have to install a WiFi repeater, and so this is no different.  In the
> case of WiFi, you can often remove the external antenna from your
> router or access point and replace it with a long-range one to get the
> WiFi to reach the dock without a repeater.  Because Z-Wave devices are
> switches, motion detectors, etc. and do not have external antennas,
> you cannot do this.  So, if you have a wireless technology that can
> reach the dock with a long range/high gain antenna, why not use it to
> extend your control network that far?  Ethernet Z-Wave interfaces are
> how you can control the Z-Wave devices in your vacation home on the
> other side of the country using your remote controls and home
> automation software back in your regular home.  Definitely not a hack
> - it's called technology!

I'm well aware of the options; I am saying that this is a particularly
stupid workaround to need when most homes will have a plethora of
line-powered ZWave devices (e.g. wall switches and wall controllers),
all of which have access to 120V and have no reason to be running a
power level that limits range to 30'.

--
Karl Denninger (karl@xxxxxxxxxxxxx)
http://www.denninger.net