Danny Tsang » energy@home

Energy@Home 0.7 Released

Danny — Wed, 23 Nov 2011 22:37:01 +0000

This new release with the main focus on multichannel support. There were a lot of paint along the way most noticeable performance issues.

The multichannel support allows for 2 or 3 phase CT clamp compatibility. Channels are different from appliances. One CC128 device can have multiple appliances. Each appliance (according to the XML spec) can have multiple channels. Each channel are captured individually and the channel label is only shown when there are more than one channel captured in the graph legend. This means that IAMs will not show the channel prefix because they can only capture one channel at a time.

The graph will display each channel like separate appliances. The changes made to the database meant the temperature data is also treated as if it was a channel and therefore reduced a lot of code specifically written for temperature data retrieval.

Other interesting changes include data filtering in the datalogger. There are now options to check the data acquired from the CurrentCost device to ensure data integrity such as garbled data or supurious data points. This still can be further improved to filter each channel but at the moment it allows for filtering of maximum appliance ID (default is 9 and is 0 based) to device name checking.

To upgrade from 0.6.5 there are a few database upgrade scripts attached to Issue 24

Download the new version at http://code.google.com/p/energyathome/downloads/list

Energy@Home 0.6.5 Released

Danny — Thu, 06 Oct 2011 21:40:00 +0000

This new release didn’t go as smoothly as planned and I had aimed to get 0.7 out the door but felt this release did not deserve the minor versioning increment so I thought I’d explain in this post.

I had acquired some Individual Appliance Monitors (IAM) which connect to the CurrentCost energy monitor. I had tried to design the software to cater for multiple channels but found that it did not work 100%. With no way of testing this was not a surprise. I had scheduled the 0.7 milestone release all for making Energy@Home work with multiple monitors but time went by so quickly I thought I’d get it to a good working state and release it so that other people can get their IAMs (or other monitors) working.

Whilst conceptually it seemed simple to add multiple monitors the code changes that went into it was fairly large. Most of the work went into the web front end to handle more than 2 data series. The database and data logger components were already geared up to accept the new channels. I guess the web GUI shows some of lack of web design experience.

The overlay function was dropped because of the response times and complexity in refactoring the code to work with and without the current energy data series. Also the data grid stopped showing the energy values but it stilled showed the date and time with the temperature. On raising a new issue in the Google Code issue tracker the page stopped loading which hampered my progress to update the issues.

In light of all the happenings above I decided to release it under 0.6 branch and work out the bugs for 0.7 release.

Web Server Basic Authentication = Weak

Danny — Sun, 15 May 2011 10:40:11 +0000

I’d like to point out that I knew Basic Authentication in web servers were not bullet proof but in fact the total opposite (pointed out in the energy@home documents). This was hammered home when I was inspired to do some optimizations on the energy@home project but I was very interested in the initial load and AJAX requests by the Google I/O 2011: Using GWT and Eclipse to Build Great Mobile Web Apps. During that process I noticed the GET request headers include an “Authorization” field with what looked like a base64 string. Low and behold entering the text into a base64 decoder and out came my username and password.

Whilst I saw this running Firebug on my local machine, it makes it very easy for a man in the middle or a sniffer to capture the packet and easily get the header and therefore decode and see the username and password.

In the mean time I have implemented HTTPS on my own installation but this does not help the majority using the software. This does not solve the problem but it does elevate the security to (try) and hinder the sniffers and firesheep like attacks.

Base 64 Decoder
Firebug FireFox Addon

energy@home 0.5 Released

Danny — Sun, 05 Dec 2010 01:04:19 +0000

I’m excited to say a new release of energy@home have been released!

The new version includes:

Offline data storage – If it was unable to save the data to the database it will save it file and later re-insert the data to be viewed online again.
Removed Twitter support due to change in authentication protocol.
Improved stability.

I’m hoping to bring back Twitter support once oAuth is supported and released in python-twitter but I may have to look for an alternative library if the project takes too long.

Offline storage is good but limited. I plan to enhance this to make it more robust in future releases.

More general tweaks and fixes as I go along.

Grab a copy at http://code.google.com/p/energyathome/

144 Bug

Danny — Sun, 21 Mar 2010 15:25:38 +0000

I have been in contact with Mark on my energy@home project and found Mark’s website which led me to a disappointing discovery – bug in the CurrentCost device.

Whilst it has not affected me yet it is somewhat disconcerning that the bug has existed over 2 generation of a product and still remains unfixed by the manufacturer.

The bug happens when multiple sensors are connected and the watts go over 3kW on either 2nd or 3rd channel. Whilst I am only using one sensor currently I was hoping the IAM sensors due to be released by CurrentCost won’t be affected. The pessimist I am I somehow doubt it if I hooked it up to a 3kW+ appliance e.g kettle.

Fridge/Freezer Anomaly Explained (Probably)

energy@home 0.4

Danny — Thu, 04 Feb 2010 22:15:10 +0000

I have just published version 0.4 of energy@home. It includes Twitter integration and a new graph which shows how much energy was used for each hour of the day.

energy@home project page

energy@home Twitter Integration

Danny — Fri, 08 Jan 2010 00:01:06 +0000

A preview of my part time project energy@home with Twitter integration.

As you can see the value for total energy used is currently way off but it’s a preview of what’s to come.

There are two options: tweet hourly summary and daily summary. These can be turned on and off. I am using python-twitter library which does not use oauth authentication so the client description comes up as API which is not nice.

Energy@Home Released On Google Code

Danny — Tue, 08 Sep 2009 21:40:16 +0000

I have formally uploaded and started using Google Code to host my energy monitor I’m using / developing.

It has been released under the GPL license so feel free to take a look at my messy code and leave some constructive criticism.

http://code.google.com/p/energyathome/