Tag Archives: home automation

Lightweight Messaging and Linux #lca2011

I’ve just delivered my talk at LinuxConf Australia 2011Lightweight Messaging for a Connected Planet. Unlike any of the other “spins” of the MQTT overview talk I’ve delivered before, this one really talks in more detail about the coding side, with shout outs to many of the members of the MQTT community and their projects. Special mentions here to Roger Light and the mosquitto project, and Nick O’Leary and the Arduino client. There has been a huge amount of discussion of Arduino and home automation (and sending Tux to the edge of space with an Arduino on a balloon… unrelated to MQTT but awesome) at LCA 2011 so these aspects turned out to fit really well.

Do let me know if you start to play around with MQTT as I believe there are some really funky things happening (some of which are highlighted in the slides). I’ve had some particularly great conversations with Andy Gelme who helped to run the Arduino Miniconf at LCA2011 and I hope to see things moving forward on his open hardware router project, too.

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The inaugural HomeCamp

As I previously mentioned, on Saturday I went along to HomeCamp 08 in London, organised by Chris Dalby and Dale Lane, and sponsored by Current Cost and Redmonk.

Low power gadgets

I was pretty actively commenting from the event and taking part in the live uStream channel… others have written up some of their experiences and thoughts, so I don’t propose to say much here. My main contribution was to make a (shaky!) video of Andy Stanford-Clark’s talk towards the start of the morning – a half hour overview of his home automation projects. I’ve posted it on Viddler, and if you are interested you are very welcome to comment on it, embed it in your own sites, or add annotations on the video timeline.

The nice part about Viddler over, say, YouTube is that it let me post the whole thing as a single video rather than having to chop it up into 10 minute chunks. I’ll try to post some notes on how I went about producing the video at some stage soon.

Some very general comments on the day:

  • Well-organised, well-run, great venue, nice to have wireless access – thanks to everyone involved in the logistics!
  • A brilliant, exciting array of skills, talents and interests. It was kind of funny to realise just how many of the folks I knew of as we were doing introductions at the start, and great to find that it wasn’t only a bunch of IBM hackers – this movement is really building momentum.
  • A lot of fun… I only wish my hacking skills were greater – but I’m looking forward to contributing and generating ideas in this community.

That’s it from me. Really looking forward to HomeCamp 09!

Current Cost

Current Cost meterThe buzz
There’s a bit of a buzz going on at work at the moment – a bunch of us from “the Hursley crowd” have started playing with Current Cost meters. These devices are intended to enable consumers to see exactly what their energy usage is and, hopefully, modify behaviour to save electricity accordingly. The idea, simply, is that it provides real-time information about energy consumption.

Rich, James, Nick and Ian have all written about their Current Cost meters already, amid much twittering and the support of @andysc.

The product
The device itself comes in two parts. The unit that goes inside the house is a wireless LCD display which shows the current usage in watts, the current estimated cost per day assuming that usage is maintained, a bar chart with yesterday’s usage, overall KWH in the past day and month, and the time and temperature.Current Cost meter The other half of the device is a somewhat larger and heavier transmitter (shown at the top of the picture, the top of the two black boxes inside our cupboard) which sits next to the electricity meter, with a clip that gently attaches around the cable (you can see that hanging off the cable at the bottom of the picture). The product is completely non-invasive and it’s incredibly easy for anyone to install: there’s no rewiring, just a clip. I was extremely impressed. It “just worked”.

Update: I should point out, given some comments, that we’re using an early batch of the meters and I’m not certain when they will be generally available.

Update: Roo points out that Eco Gadget Shop have them for sale to consumers, minus data cable.

The impact

One of the other features of the device is that it can be plugged in to a computer, and the data can then be captured and analysed over time. We are using some homebrew software to do this, pulling the data from the serial port (most of the meters use 9600 baud, it turns out that mine is set to 2400 for some reason).

Current Cost graph

It’s kind of scary to see some of the spikes in the graph, and just watching this has certainly made me adjust my behaviour in terms of switching things off and unplugging chargers and so on when they are not in use. We’ve all got our meters hooked up via a Microbroker, and this has been my first opportunity to really play around with MQTT technology… I’ve obviously been aware of it for a very long time, but it’s nice to have something tangible to hack around with. It has also led me into a bunch of interesting discussions about home automation, tweetjects and low-power servers. Fascinating stuff.

The ideas

I have a bunch of thoughts about this. I have it hooked up to an old Linux box, but I’ve also successfully attached it to my Macbook Pro and a Windows Thinkpad. Currently the software is sending the MQTT data to a Microbroker and a Java app is drawing the graph shown above, but it would be fairly straightforward, for example, to squirrel the data locally and do some interesting analytics using Project Zero (aka WebSphere sMash) and some AJAX-y Google Chart goodness. I can also capture ambient temperature over time. It’s all just a matter of finding the hacking opportunity!