Thursday, December 18, 2008

The solar works

In the loft
The solar panels are connected to an inverter (right - click photos to enlarge) , which converts the DC generated current into AC, using the "only clever bit" of the entire installation, according to the installer. This is mounted just inside the entrance to the loft. The interesting thing about the blue box is the "knock interface"... to switch on the unit and light up the screen you have to knock on the grey area. The screen tells you how many watts the panels are generating, and how much have been produced during the day, and how much in total.

In the kitchen
Downstairs, next to the consumer unit is a fantastic red knob, which isolates the panels. Above it is a meter which also shows how much electricity has been generated by the panels in total. During the first day of operation, the unit generated a total of 700W - disappointing considering it was bright sunshine outside all day, and the unit is spec'd at 1000W per hour. The installation engineer reassured me that as the sun got higher during the summer months the unit would generate much more - we shall see! During the second day of operation, when it was cloudy, the unit generated a total of just 200W during the day. Not good.

The electricity meter has been switched to an import / export meter. The meter gives the amount exported to the National Grid (ie total produced by the solar panel minus total consumed at the time in the house), and also the amount imported from the Grid. You can see the current cost clamp in the picture. This is interesting, because the current cost meter measures the flow of electricity regardless of which way it flows... so it reads 100W when the house consumes 100W, and it reads 100W when the house exports 100W. It was highly confusing turning on a light to see the amount on the meter decrease! So one of my Christmas projects is to connect another meter to the solar panel cable, and add the two readings together in order to get a sensible output... more on that later.

Tuesday, December 16, 2008

Solar Panel installation

Here's a photo of the solar panels which were fitted to our roof today by Rayotec. They should provide us with 1kW electricity per hour in peak sunshine, but just around 100W per hour in horrible foggy weather like today. Tomorrow morning they will be grid connected, so any extra electricity we don't use will go back into the grid. With Southern Electricity giving us slightly more per unit than we pay for our electricity, there's still an incentive to use as little as we can. We expect the unit to just about cover our usage, over a yearly period. It cost around the same as having all our doors and windows replaced a few years ago and we're promised a similar length of service. So, we're just looking forward to the grand switching-on ceremony tomorrow morning!

Monday, November 24, 2008

Mind reading headsets

So far, the mind reading headset market aimed at the regular consumer is quite small... I've come across the well advertised Emotiv headset, to be released early next year, and OCZ's "Neural Impulse Activator", shown right.

Unlike the Emotiv headset, with 16 different sensors placed on different parts of the head, this unit only has 3, all placed across the forehead, inevitably giving slightly less function.

In the first several hours of playing with the device, I managed to work out what successful calibration "looked like": - when the muscle signal graph didn't vary away from the "desired baseline". Sometimes this was very easy to achieve, and other times, just didn't happen. I discovered it worked better on one side of the lounge at home, than on the other. I also concluded that wetting the 3 sensors with water helped to a degree. Unfortunately the device needs to be calibrated every time it is used, which makes demonstrations rather hit-and-miss.

My first successful experience came shortly after calibrating the device. I was able to play the game of pong, using my eyebrows. By wiggling them fractionally upwards, the bat went up, and wiggling them downwards, the bat went down. And whilst I didn't ever manage to win a whole game, I did hit the ball enough times to win a few points, so it was not all chance.

My other successful experience was linking the muscle movements to keypresses, so I could use my eyebrows to navigate around Google maps. An eyebrow up-wiggle mapped to Page Up, and sent the map flying in one direction, a down-wiggle mapped to Page Down, and sent it flying in the other. Unfortunately zooming in and out was a bit beyond me, as the '+' key was unmappable.

So how is this mind-reading? Well, unfortunately it isn't yet. Unlike the Emotiv device, it seems impossible to "train" the device to recognise when you are thinking of stroking a cat for example. As found in this review, it should be able to detect general mood - OCZ's VP Dr. Schuette, says he can think of an expletive to make his Alpha 2 increase enough to trigger a "jump" action in his computer game. However I suspect this takes many hours of practice!

So for now, I shall continue playing pong with my keyboard, and wait for a few weeks when I hope to be able to get my hands on the Emotiv headset.

Friday, October 24, 2008

I recently bought a viglen MPC, and installed Xubuntu it using some very good instructions from Andy SC. I added a USB dongle for wireless, and another one for bluetooth (for later experiments). I then linked my current cost meter to it, to try out some code from Dale Lane's blog. I first needed to install a number of pre-reqs, so I thought I would document them here.

First, I expanded the into a directory, and ran the code:
sudo python currentcost.pyc

This gave an ImportError for module wx. Although I tried installing easy_install, this did not install anything successfully for me, so I followed these instructions to install the wxpython modules. Next, the following commands allowed the other pre-reqs to be installed:
sudo apt-get install python-numpy
sudo apt-get install python-matplotlib
sudo apt-get install python-serial
sudo apt-get install python-simplejson
sudo apt-get install python-pysqlite2

The application then worked! To determine which port to use, I typed:
dmesg | grep tty

The third line of the output said "converter now attached to ttyUSB0"
When you connect, the port should therefore be: /dev/ttyUSB0

Tuesday, October 14, 2008

How to communicate if you can barely move

My wife works with people who have had head injuries or strokes, who cannot move from the neck down and sometimes cannot talk; some are mentally active, which must be even more frustrating. Even in this day of great technology, letters are drawn on paper, and letter by letter the person moves their head from one side to the other side to indicate if this is the next letter in the sentence. As you can imagine, this takes a very long time, and it cannot be used to initiate a conversation.

Recently, I've been playing with a very good piece of software aimed at eye tracking called Dasher. This allows letters, which move in from the right of the screen, to be selected one by one by moving the mouse up and down and gradually forming a sentance. It is also predictive, so if for example you have selected H and then e, llo would be close together. It runs on multiple operating systems.

Secondly, my colleage Dave CJ has created a fantastic python script to control the mouse pointer on a Ubuntu PC using the accelerometer on the Nokia N95 via bluetooth.

So... by combining the two, I can tilt the N95 from side to side, to move the mouse on the PC and select letters in a sentence. OK, so balancing a phone on your head looks slightly stupid, but if it helps open up a means of communication without any specialist equipment, or the help of someone else, it surely must be a good thing.

Monday, September 15, 2008

I've changed my name, thanks to Google

Having a common name like Kevin Brown is a bit of a problem when it comes to getting a consistent, unique id on the various different web sites like blogger, twitter and the like. I have experimented with a range of ids... but over this weekend I decided I'd go for a more radical option - to change my name.

I had a search on Google and discovered that kevinxbrown, kevinybrown and kevinzbrown all returned no search results - which surprised me a lot! Have no other Kevin Brown's in the world got a middle name starting with these letters? So I've now adopted the middle name Xavier (well, what other names start with X?) Sorry to my twitter community who I totally confused over the weekend with my little identity crisis - ignore my invitations - I think I'm back in one piece as kevinxbrown.

Yours forever (or until the next name change), Kevin Xavier Brown.

Wednesday, September 3, 2008

Emerging HCI technologies

I find it very old fashioned and frustrating to sit down in the office every day and look into a box, whilst pressing my fingers rapidly on little pieces of plastic representing letters, and moving a small plastic box from side to side. It's not natural and can't be that healthy - ignoring the mandatory pizzas and Hobnobs consumed whilst doing so. The QWERTY keyboard was patented in 1878, and the mouse is 40 years old - so given the advancement everywhere else in technology, it's about time we got something else that beats it.

The good news is there are many exciting technologies which are either newly with us, just around the corner or have been reduced to a price which is accessible for the average user. I've been following some of them, such as embedded ViaVoice for talking to machines in a natural way, "mind reading" headsets such as the one from Emotiv aimed at gamers and due for release in December, wearable displays which allow you to augment reality with your own data - and mobile phone projectors all to be released in the next few months - as well as haptic user interfaces like this ultrasound device written about on the BBC today. I think the next few months and years will be very exciting! Just been playing with an OCZ NIA but that's a post all of it's own....