The Kitchen Node

In the kitchen, we currently have an ageing X10 based system to switch three light circuits. When we moved in, all three lights were on the same circuit, so the kitchen was either dark or blazing. I couldn't reach all the wires to put in a new threeway switch, so I had to fit a remote system. It's not terribly robust, there is a noticeable delay between pressing the button and the light switching, and the switch itself is not very intuitive (I keep pressing the wrong buttons). 

The first task for the new system will therefore be to replace the X10 relays. The controller will be a USB jeenode. After looking at many different arduino based systems, my conclusion is that jeenodes offer the best design for my home system - they are very cheap, have radio built in, convenient connectors, and offer a small form factor.

I initially planned to use two Relay plugs for the three lights, but in the end decided to go for three relay nodes from a different supplier (Ciseco). My budget is very tight, and this option is a bit cheaper - they'll be wired straight to the jeenode's pins (using up two of the four connectors). I've also dropped the jeenode's carrier board and box - I'm sure I can find two plastic boxes, one for the node, and one for the relays to keep the high voltage bits separate.

On one of the remaining connectors, I'll connect a temperature sensor. The room board would be nice, but had to go for now;I can add that later when there's a bit more money.

Home Energy Controller

And this is my big new project: building a system that makes it easy to control and monitor the energy we use at home.

I have a strong interest in environmental conservation, and in energy use. I took part in Nesta/UKERC's Carbon Crucible program, and I had EPSRC funding for a feasibility study in analysis of energy monitoring data. The UK is trailing behind many other EU nations when it comes to real, implemented CO reductions (they just keep announcing things and then not realizing them). Taking action locally seems the only way to achieve at least some level of improvement.

The other reason for this project is that I want to build up some experience in embedded devices, play a bit more with Android, and after a long break get back to tinkering with electronics.

It all started with the Raspberry Pi excitement - $25 for a small but powerful Linux based computer - so many things one can do with it. Initially I was thinking about connecting to the systems in our car (I am currently working with an automotive engineering company),  but then I found the Open Energy Monitor page - offering open hardware and software for home energy monitoring. That seemed a much more useful project - and one where I could justify (to myself and the rest of the family) spending the time and money.

The current plan calls for three nodes: one in the kitchen, providing the user interface and replacing the ageing X10 based light control; one in the laundry controlling and metering the boiler, and one in the lobby metering gas, electricity, and quite a few temperatures indoors and outside. The overall bill of parts should hopefully stay bellow £250.