

Controling power outlets via Bluetooth - aeolus42
http://www.kickstarter.com/projects/zuli/zuli-smartplugs

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dangrossman
I don't quite see why they want to make this.

Remote controllable power outlets have existed for a very long time. At this
point, you have dozens of options, and several home automation industry
standards that allow all these options to interconnect with each other. You
can combine plugs, light switches, motion sensors, keypads, door openers,
thermostats and virtually everything else in your house with any brand's
Zigbee or Z-wave hub, or directly from a PC/app over wifi.

Z-wave/Zigbee are already low-power mesh networks. I don't think there's any
advantage to re-implementing that over Bluetooth with a different protocol,
while the disadvantages if you ever want to do more cool home automation stuff
than just power plugs are many.

If for some reason this all sounds scary and you'd prefer just plugging
something into the wall and using an app, that's been on the market for years
too. The easiest way to get started is to walk into your nearest Best Buy or
Home Depot and pick up a Belkin Wemo switch. It plugs into any outlet just
like this Kickstarter but connects to your wifi network instead of BT. There's
an Android app to control the plugs (from inside the house or over the
internet), but they also speak UPnP so are easy to integrate into your own
software.

~~~
matthewbadeau
I believe they went with bluetooth because all smartphones have it, it doesn't
require a special base station and can send simple serial commands fairly
easily from an iOS app.

Honestly though, I prefer wi-fi over bluetooth because I can connect to an
entire network of smart devices. Bluetooth would limit me to one device at a
time.

~~~
Someone
This claims to create a mesh network. If that's done well, you should be able
to talk to all devices at once, even outside of regular Bluetooth range.

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lhl
There's another pretty similar Kickstarter project going on right now. It's
wifi (802.11n) vs BLE - looks pretty sharp. It lacks beaconing but has a
similar open API and also looks pretty well designed:
[http://www.kickstarter.com/projects/plugaway/plugaway-
your-s...](http://www.kickstarter.com/projects/plugaway/plugaway-your-smart-
home-on-your-smart-phone)

Both have online load/consumption monitoring (I wonder how exactly the Zuli
stores/handles that when there's no app around?), which are probably the
biggest thing separating them from existing remote power outlet products.

(For logging power, the only relatively cheap options I've found is hacking a
Kill-A-Watt sensor chip (see: [http://www.mikesmicromania.com/2013/04/moteino-
kill-watt-har...](http://www.mikesmicromania.com/2013/04/moteino-kill-watt-
hardware.html) ) or buying a Watts up? PRO - both are more much more
expensive/involved solutions than either of these two new devices.)

~~~
johladam
I believe that one way to measure the current for relatively cheap would be to
break the neutral line and throw a current-sensing resistor in it. It would
create a small voltage drop across the resistor. If you know the voltage drop
and the resistor value, it should be pretty trivial to determine the current
through the neutral line. Equation to do that would be:

lineCurrent = (Voltage of the current-sense resistor) / (resistance of the
current-sense resistor)

Considering a current sense resistor is fairly cheap
([http://octopart.com/13fr200e-ohmite-988758](http://octopart.com/13fr200e-ohmite-988758))
it shouldn't be terribly expensive to do. You should be able to throw that
between a Vin- and Vin+ on a linear optoisolator and send the values back to a
microcontroller to be reported.

I'm not an EE though, so grain of salt.

~~~
lhl
Yeah, in theory you could build your own but having something UL rated is an
advantage. AC is a lot more dangerous than DC, so you should really know what
you're doing before mucking around.

There are a few more components for building a basic board:
[https://instruct1.cit.cornell.edu/courses/ee476/FinalProject...](https://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2008/cj72_xg37/cj72_xg37/index.html)
[http://enerjar.net/Hardware.html](http://enerjar.net/Hardware.html)

Building a more accurate power meter is pretty involved:
[http://coolarduino.wordpress.com/2013/02/08/power-
meter/](http://coolarduino.wordpress.com/2013/02/08/power-meter/)
[http://coolarduino.wordpress.com/2013/02/27/power-energy-
met...](http://coolarduino.wordpress.com/2013/02/27/power-energy-meter-phase-
power-and-energy/)

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wch
Is it possible to use more than one device to control an outlet? As far as I
know, Bluetooth devices can only be paired to one other device at a time. If
that's the case here, then the outlet is tied to (for example) one phone --
but I might have a couple phones, tablets, and computers from which I'd want
to control the outlet.

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ars
Bluetooth doesn't seem right for this - the range is just too short to really
be useful.

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colinbartlett
It's interesting to me to see all these new fangled home automation devices
come to market, especially when really inexpensive technology has been around
for decades: [http://www.x10.com](http://www.x10.com)

~~~
jbuzbee
I've used x10 on and off since the early 80's. And... it sucks. When it works,
it's cool, fun and cheap. But reliable it's not. For starts, all the
inexpensive units I've used only support one-way commanding and the commands
are susceptible to collision. Send a command to turn a light off and just hope
that it goes off. Want to dim a light? All the commands are incremental so
you'll have to do stuff like send 8 dim commands to get to a known minimum
state then send 4 brighten commands to brighten to the desired level. And
since it's one-way with no acknowledgments, you just hope that your commands
were received and that the light was on to start with. Fun to play with, but
I'd never trust it for anything but toy usage.

~~~
frob
I've been using Insteon for a few years now (insteon.com). It's like x10 done
right. There are acknowledgments, grouping, security, 256 brightness levels,
extended commands, wifi+power-line communications, and a 6-byte namespace (for
no collisions).

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andrewtbham
The title should probably read "Control power outlets via Bluetooth Low
Energy"

[http://en.wikipedia.org/wiki/Bluetooth_low_energy](http://en.wikipedia.org/wiki/Bluetooth_low_energy)

It's BlueTooth Low energy, a fairly recent standard, the technology used in
iBeacons. It's range is about perfect for a room. Several of the comments seem
to be considering the older bluetooth standards.

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moocowduckquack
Why is there _nothing_ about security mentioned there?

~~~
catch23
Probably because it leverages the security built into bluetooth.

~~~
moocowduckquack
That does not reassure me.

 _" We discuss our tools and techniques to monitor and inject packets in
Bluetooth Low Energy. Also known as BTLE or Bluetooth Smart, it is found in
recent high-end smartphones, sports devices, sensors, and will soon appear in
many medical devices. We show that we can effectively render useless the
encryption of any Bluetooth Low Energy link."_

[https://www.usenix.org/conference/woot13/workshop-
program/pr...](https://www.usenix.org/conference/woot13/workshop-
program/presentation/Ryan)

------
aeolus42
zuli.io

