Power, SSL and nanoblogging

As some of you may know, we have a CurrentCost meter in our house.  And we both have iPhones.  So it seemed obvious to provide a method to display the power usage of our house in an iPhone-compatible way so that we can check up on things while we’re out.

To that end, I created h.nomzit.com, which is a view into the power-consumption of our house.  On an iPhone it looks something like this:

h.nomzit.com as seen on iPhone

Obviously you can tell when we’re on holiday from our power consumption, and it’s a bad idea therefore to broadcast that to all-and-sundry. Which is why you’ll notice that the data on that page is delayed by 14 days.

However, 14-days out-of-date data is not very useful to the inhabitants of the house, whereas live data is. To get around this I have an SSL-enabled version of h.nomzit.com which uses client certificates to verify that it’s Cerys or I who’s asking for data before giving out the current information. I chose to use client certificates from cacert.org rather than username/password exchange because it saves the hassle of entering a username/password pair on a phone. HTTPS is slow enough over 1 bar of 2G without introducing a human interaction into the picture.

Having gone to the trouble of configuring SSL and installing client certificates on our iPhones, it is easy to add more identity-based services.  So we now have our own food- and drink-oriented nanoblogging service on p.nomzit.com, which allows us to record what we eat/drink, when, and what we thought of it. Food is red, drinks are blue, the coloured blobs are green, blue, or red according to whether the food/drink was good, ok, or bad.  The time is set by the server as it receives the information from us

Looks something like this:


What’s next?  Don’t know yet – but there are 24 more letters to choose from.

2 Responses to “Power, SSL and nanoblogging”

  1. Richard

    Hi Phil,

    What a great idea – nice article, too. I’m about to have a go at creating my own set of applications to interface with CurrentCost, should be fun :)



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