fixing firefox’s fugly fonts on Ubuntu

Switching back to Linux from Mac is still a process of ironing out minor wrinkles. Take, for example, this abomination (enlarged to show texture):—

Screenshot from 2013-05-19 11:42:18

… No, I’m not talking about Mr Paul’s antics (or the typo in the TP post, either), but the horrid non-matching ligatures (‘attack’, ‘flubbed’, ‘targeting’) in a sea of blocky text. Almost every programme I was running had this problem. Mouse over the image to see how it could look if you apply this easy fix.

Create (or edit) ~/.fonts.conf, and add the following lines:

<match target="font" >
  <edit name="embeddedbitmap" mode="assign">
    <bool>false</bool>
  </edit>
</match>

Log out, log back in again, and text is properly pretty. Yay!

clean up your GnuPG keyring

For reasons too annoying to explain, my GnuPG keyring was huge. It was taking a long time to find keys, and most of them weren’t ones I’d use. So I wrote this little script that strips out all of the keys that aren’t

  1. yours, or
  2. signatories to your key.

The script doesn’t actually delete any keys. It produces shell-compatible output that you can pipe or copy to a shell. Now my keyring file is less than 4% the size (or more precisely, 37‰) of the size it was before.

#!/bin/bash
# clean_keyring.sh - clean up all the excess keys

# my key should probably be the first secret key listed
mykey=$(gpg --list-secret-keys | grep '^sec' | cut -c 13-20 | head -1)
if
    [ -z $mykey ]
then
    # exit if no key string
    echo "Can't get user's key ID"
    exit 1
fi

# all of the people who have signed my key
mysigners=$(gpg --list-sigs $mykey | grep '^sig' | cut -c 14-21 | sort -u) 

# keep all of the signers, plus my key (if I haven't self-signed)
keepers=$(echo $mykey $mysigners | tr ' ' '\012' | sort -u)

# the keepers list in egrep syntax: ^(key|key|…)
keepers_egrep=$(echo $keepers | sed 's/^/^(/; s/$/)/; s/ /|/g;')

# show all the keepers as a comment so this script's output is shell-able
echo '# Keepers: ' $keepers

# everyone who isn't on the keepers list is deleted
deleters=$(gpg --list-keys | grep '^pub'|  cut -c 13-20 | egrep -v ${keepers_egrep})

# echo the command if there are any to delete
# command is interactive
if
    [ -z $deleters ]
then
    echo "# Nothing to delete!"
else
    echo 'gpg --delete-keys' $deleters
fi

Files:

Compose yourself, Raspberry Pi!

Years ago, I worked in multilingual dictionary publishing. I was on the computing team, so we had to support the entry and storage of text in many different languages. Computers could display accented and special characters, but we were stuck with 8-bit character sets. This meant that we could only have a little over 200 distinct characters display in the same font at the same time. We’d be pretty much okay doing French & English together, but French & Norwegian started to get a little trying, and Italian & Greek couldn’t really be together at all.

We were very fortunate to be using Sun workstations in the editorial office. These were quite powerful Unix machines, which means that they were a fraction of the speed and capabilities of a Raspberry Pi. Suns had one particularly neat feature:

Compose_key_on_Sun_Type_5c_keyboard(source: Compose key, Wikipedia.)

That little key marked “Compose”  (to the right of the space bar) acted as a semi-smart typewriter backspace key: if you hit Compose, then the right key combination, an accented character or symbol would appear. Some of the straightforward compose key sequences are:

  Compose +    
Accent First key Second key Result Example
Acute e é café
Grave ` a à déjà
Cedilla , c ç soupçon
Circumflex ^ o ô hôtel
Umlaut u ü küche
Ring o a å Håkon
Slash / L Ł Łukasiewicz
Tilde ~ n ñ mañana

Like every (non-embedded) Linux system I’ve used, the Raspberry Pi running Raspbian can use the compose key method for entering extra characters. I’m annoyed, though, that almost every setup tutorial either says to disable it, or doesn’t explain what it’s for. Let me fix that for you …

Setup

Run raspi-config

sudo raspi-config

and go to the configure_keyboard section. Your keyboard’s probably mostly set up the way you want it, so hit the Tab key and select <Ok> until you get to the Compose key section:

raspi-config: Compose key selectionChoose whatever is convenient. The combined keyboard and trackpad I use (a SolidTek KB-3910) with my Raspberry Pi has a couple of “Windows® Logo” keys, and the one on the right works for me. Keep the rest of the keyboard options the same, and exit raspi-config. After the message

Reloading keymap. This may take a short while
[ ok ] Setting preliminary keymap...done.

appears, you now have a working Compose key.

Using the Compose key

raspi-config hints (‘On the text console the Compose key does not work in Unicode mode …’) that Compose might not work everywhere with every piece of software. I’ve tested it across quite a few pieces of software — both on the text console and under LXDE — and support seems to be almost universal. The only differences I can find are:

  • Text Console — (a. k. a. the texty bit you see after booting) Despite raspi-config’s warning, accented alphabetical characters do seem to work (é è ñ ö ø å, etc). Most symbols, however, don’t (like ± × ÷ …). The currency symbol for your country is a special case. In Canada, I need to use Compose for and £, but you’ve probably got a key for that.
  • LXDE — (a. k. a. the mousey bit you see after typing ‘startx’) All characters and symbols I’ve tried work everywhere, in LXTerminal, Leafpad, Midori, Dillo (browser), IDLE, and FocusWriter (a very minimal word processor).
Special characters in Python's IDLE

Special characters in Python’s IDLE

Some Compose key sequences — Leafpad

Some Compose key sequences — Leafpad

To find out which key sequences do what, the Compose key – Wikipedia page is a decent start. I prefer the slightly friendlier Ubuntu references GtkComposeTable and Compose Key, or the almost unreadable but frighteningly comprehensive UTF-8 (Unicode) compose sequence reference. Now go forth and work that Compose key like a boß.

(If you’re on a Mac and feeling a bit left out, you can do something similar with the Option key. Here’s how: Extended Keyboard Accent Codes for the Macintosh. On Windows®? Out of luck, I’m afraid.)

Hint: I don’t do this for the money …

I don’t know why getting an e-mail like this one would disturb me so much:

Hi Stewart,

Just a quick reminder message – I’m currently working with [REDACTED], a top electronics and engineering tech company, and we’re still interested in collaborating with you!

We can provide bespoke content by [REDACTED]‘s own tech copywriters to give you something relevant for your readers, based on a topic that you’d like us to write about. We can also offer a $25 voucher to purchase any product of that value or less from the [REDACTED] website (http://www.[REDACTED].com/) which you could then use and review.

If you’re interested, I can send over some rough content ideas for you to have a look at, and you can let us know what grabs you.

Look forward to hearing from you!

Best,
[REDACTED]

It’s not spam; I’ve had this offer before via another channel. I can’t see why anyone would want someone else’s text under their own byline. Running this blog costs me a trivial amount of money, but I’m okay with that. Monetizing, SEO, sticky eyeballs (I’m showing my age …): feh. All I ever wanted to do with this blog is write my own drivel without someone else’s noise polluting the page.

Mac to Linux: 1Password to KeePassX

I have too many passwords to remember, so I’ve been using a password manager for years. First there was Keyring for Palm OS, then 1Password on the Mac. 1Password’s a very polished commercial program, but it only has Mac and Windows desktop clients. Sadly, it had to go.

Finding a replacement was tough. It needed to be free, and yet cross-platform. It needed to work on iOS and Android. It also needed to integrate with a cloud service like Dropbox so I could keep my passwords in sync. The only program that met all of these requirements was KeePassX. I’ve stuck with the stable (v 0.4.3) branch rather than the flashy 2.0 version, as the older database format does all I need and is fully portable. MiniKeePass on iOS and KeePassDroid on Android look after my mobile needs. But first, I needed to get my password data out of 1Password.

1Password offers two export formats: a delimited text format (which seemed to drop some of the more obscure fields), and the 1Password Interchange Format (1PIF). The latter is a JSONish format (ಠ_ಠ) containing a dump of all of the internal data structures. There is, of course, no documentation for this file format, because no-one would ever move away from this lovely commercial software, no …

So armed with my favourite swiss army chainsaw, I set about picking the file apart. JSON::XS and Data::Dumper::Simple were invaluable for this process, and pretty soon I had all the fields picked apart that I cared about. I decided to write a converter that wrote KeePassX 1.x XML, since it was readily imported into KeePassX, would could then write a database readable by all of the KeePass variants.

To run this converter you’ll need Perl, the JSON::XS and Data::Dumper::Simple modules, and if your Perl is older than about 5.12, the Time::Piece module (it’s a core module for newer Perls, so you don’t have to install it). Here’s the code:

#!/usr/bin/perl -w
# 1pw2kpxxml.pl - convert 1Password Exchange file to KeePassX XML
# created by scruss on 02013/04/21

use strict;
use JSON::XS;
use HTML::Entities;
use Time::Piece;

# print xml header
print <<HEADER;
<!DOCTYPE KEEPASSX_DATABASE>
<database>
 <group>
  <title>General</title>
  <icon>2</icon>
HEADER

##############################################################
# Field Map
#
# 1Password			KeePassX
# ============================  ==============================
# title        			title
# username			username
# password			password
# location			url
# notesPlain			comment
#    -				icon
# createdAt			creation
#    -				lastaccess	(use updatedAt)
# updatedAt			lastmod
#    -				expire		('Never')

# 1PW exchange files are made of single lines of JSON (O_o)
# interleaved with separators that start '**'
while (<>) {
    next if (/^\*\*/);    # skip separator
    my $rec = decode_json($_);

    # throw out records we don't want:
    #  - 'trashed' entries
    #  -  system.sync.Point entries
    next if ( exists( $rec->{'trashed'} ) );
    next if ( $rec->{'typeName'} eq 'system.sync.Point' );

    print '  <entry>', "\n";    # begin entry

    ################
    # title field
    print '   <title>', xq( $rec->{'title'} ), '</title>', "\n";

    ################
    # username field - can be in one of two places
    my $username = '';

    # 1. check secureContents as array
    foreach ( @{ $rec->{'secureContents'}->{'fields'} } ) {
        if (
            (
                exists( $_->{'designation'} )
                && ( $_->{'designation'} eq 'username' )
            )
          )
        {
            $username = $_->{'value'};
        }
    }

    # 2.  check secureContents as scalar
    if ( $username eq '' ) {
        $username = $rec->{'secureContents'}->{'username'}
          if ( exists( $rec->{'secureContents'}->{'username'} ) );
    }

    print '   <username>', xq($username), '</username>', "\n";

    ################
    # password field - as username
    my $password = '';

    # 1. check secureContents as array
    foreach ( @{ $rec->{'secureContents'}->{'fields'} } ) {
        if (
            (
                exists( $_->{'designation'} )
                && ( $_->{'designation'} eq 'password' )
            )
          )
        {
            $password = $_->{'value'};
        }
    }

    # 2.  check secureContents as scalar
    if ( $password eq '' ) {
        $password = $rec->{'secureContents'}->{'password'}
          if ( exists( $rec->{'secureContents'}->{'password'} ) );
    }

    print '   <password>', xq($password), '</password>', "\n";

    ################
    # url field
    print '   <url>', xq( $rec->{'location'} ), '</url>', "\n";

    ################
    # comment field
    my $comment = '';
    $comment = $rec->{'secureContents'}->{'notesPlain'}
      if ( exists( $rec->{'secureContents'}->{'notesPlain'} ) );
    $comment = xq($comment);    # pre-quote
    $comment =~ s,\\n,<br/>,g;  # replace escaped NL with HTML
    $comment =~ s,\n,<br/>,mg;  # replace NL with HTML
    print '   <comment>', $comment, '</comment>', "\n";

    ################
    # icon field (placeholder)
    print '   <icon>2</icon>', "\n";

    ################
    # creation field
    my $creation = localtime( $rec->{'createdAt'} );
    print '   <creation>', $creation->datetime, '</creation>', "\n";

    ################
    # lastaccess field
    my $lastaccess = localtime( $rec->{'updatedAt'} );
    print '   <lastaccess>', $lastaccess->datetime, '</lastaccess>', "\n";

    ################
    # lastmod field (= lastaccess)
    print '   <lastmod>', $lastaccess->datetime, '</lastmod>', "\n";

    ################
    # expire field (placeholder)
    print '   <expire>Never</expire>', "\n";

    print '  </entry>', "\n";    # end entry
}

# print xml footer
print <<FOOTER;
 </group>
</database>
FOOTER

exit;

sub xq {                         # encode string for XML
    $_ = shift;
    return encode_entities( $_, q/<>&"'/ );
}

To run it,

./1pw2kpxxml.pl data.1pif > data.xml

You can then import data.xml into KeePassX.

Please be careful to delete the 1PIF file and the data.xml once you’ve finished the export/import. These files contain all of your passwords in plain text; if they fell into the wrong hands, it would be a disaster for your online identity. Be careful that none of these files accidentally slip onto backups, too. Also note that, while I think I’m quite a trustworthy bloke, to you, I’m Some Random Guy On The Internet. Check this code accordingly; I don’t warrant it for anything save for looking like line noise.

Download: 1pw2kpxxml.zip (gpg signature: 1pw2kpxxml.zip.sig)

SHA1 Checksums:

  • 3c25eb72b2cfe3034ebc2d251869d5333db74592 — 1pw2kpxxml.pl
  • 99b7705ff30a2b157be3cfd29bb1d4f137920c25 — readme.txt
  • de4a51fbe0dd6371b8d68674f71311a67da76812 — 1pw2kpxxml.zip
  • f6bd12e33b927bff6999e9e80506aef53e6a08fa — 1pw2kpxxml.zip.sig.txt

The converter has some limitations:

  • All attached files in the database are lost.
  • All entries are stored under the same folder, with the same icon.
  • It has not been widely tested, and as I’m satisfied with its conversion, it will not be developed further.

Ubuntu on the Samsung Series 7

My Late 2008 MacBook was getting a little slow, so I went laptop shopping. I ended up with the Samsung Chronos 7 (NP700Z5CH). Under my budget, but met my spec in every way.

Installing Ubuntu was a minor trial, but it works, and has preserved the Win 8 (blecch!) dual-boot. If it helps anyone, the procedure I followed was:

  • Updated the BIOS, made a recovery DVD and shrank the Windows partition using the DISKPART app (which reminds me so much of the old VMS admin tools).
  • Broadly following the UEFI instructions, I got the 64-bit Linux-Secure-Remix ISO and wrote it to a USB stick with UNetbootin.
  • In the BIOS (F2 when the Samsung logo shows), I disabled Secure Boot and Fast Boot, but kept EFI on, as Win8 won’t work without it. I also disabled (temporarily, with Shift+1) the HD and Windows Boot Manager from the boot sequence, moving USB boot up to first place.
  • After trying Ubuntu from the LiveUSB, I installed it. Once it had finished and rebooted, I re-enabled HD and Windows Boot Manager in the BIOS.
  • Ubuntu would work fine from here, but to restore Win8 to a usable (?) state, I had to reboot with the LiveUSB image and run Boot-Repair as suggested in the UEFI documentation.

The fan maybe runs a little more than it should, but everything I’ve tried works. There’s clearly been a lot of work done on Samsung/UEFI support recently, as any of the web tutorials I found from even 8 months ago recommended really arcane stuff I didn’t actually need.

(abstracted from my Reddit query: Linux-friendly future-proof MacBook replacement [13-15", CA, $1600] : SuggestALaptop)

A better image rollover with Ultimate TinyMCE

iheartslothsProbably best to retire my ad hoc image rollover in wordpress, as Ultimate TinyMCE has it covered. Sure, it’s a plugin, but it makes it so much easier. After uploading your two images, select an image and put the two URLs into the Mouse Over/Out fields:

Ultimate TinyMCE image rollover

Easy! And no digging into the page source, either.

Wind Power, 1940s style

smith putnam wind turbineThis is how wind turbines were supposed to look, at least in the 1940s. It’s the experimental Smith-Putnam 1.25 MW unit than ran for a short while on a hill near Rutland, VT. The picture’s from a rather falling-apart copy of Large Horizontal-axis Wind Turbines (Thresher, R. W., & Solar Energy Research Institute. (1982). Large horizontal-axis wind turbines: Proceedings of a workshop held in Cleveland, Ohio, July 28-30, 1981. Golden, Colo: Solar Energy Research Institute) that I rescued from Jim‘s recycling years ago.

The first part of these proceedings has a historical review of the Smith-Putnam turbine, including an excerpt from the S. Morgan Smith Company’s house organ on the project. As the rest of the book is pretty much all about the MOD series of turbines, it’s of less interest. I’ve scanned the bits about the Smith-Putnam turbine, and put them here: NASA_DOE-1981-large_horizontal_axis_wind_turbines-excerpt. If anyone wants the book, let me know. It’s very ratty, but readable.

I’ve written about this turbine before, but in relation to a packet of crayons. More awesome turbine pictures from Paul Gipe: Smith-Putnam Industrial Photos.

Forward to Libraries: Toronto Public Library added

If you’re starting your research on Wikipedia, you’ll need to see what books are available on a subject for further study. Previously, you’d need to trawl the references manually, but John Mark Ockerbloom‘s Forward To Libraries (FTL) service makes that a whole lot easier. What FTL does is allow you to reach into nearly any library’s catalogue search from a subject link on Wikipedia.

John’s been getting some great press on this service, so I asked him to add Toronto Public Library to FTL. Here’s how it works:

Pretty neat, huh? Try other articles, like Pierre Trudeau, Arduino or the Canadian Shield.

It’s not actually that hard to add Library resources boxes to Wikipedia articles. There’s a tutorial in the Template:Library resources box page that shows you how. Researching the locator is the most difficult part, and that gets a lot easier the more you add.

X11-Basic: Compiler Insanity!

Screen Shot 2013-03-11 at 22.13.31Markus Hoffmann has been very helpful with getting X11-Basic running on the Raspberry Pi. Remember how I said that the simple Mandelbrot Set test took nearly 1¼ hours to run using the interpreter? How about 2′ 6″ when compiled? That’s a speedup of 35 times! What you need to do is:

xbc -virtualm -o mandel-simple mandel-simple.bas

The “-virtualm” bit is the secret key to speed. Without it, the compiled code is a bit faster than interpreted.

If you’re running from the source code posted to SourceForge yesterday, you might want to replace xb2csol.h with this new xb2csol.h. It’s supposed to help with the compiled code. Just make clean; make; sudo make install to replace the code.

Running X11-Basic (almost perfectly) on Raspberry Pi

Update: Markus Hoffmann uploaded a new version of X11Basic-1.20.tar.gz to SourceForge that addresses most of these problems. I’ve edited the article to remove the obsolete bits.


More than 20 years ago, I really liked GFA-Basic. It ran blindingly fast on the Atari ST, and when it didn’t crash on the Amiga, it ran blindingly fast there too. I even wrote a review of it for comp.sys.amiga.programmer, which you can read to this day in all its textual glory. One of the e-mail addresses in that article still works, too.

I still sometimes think in BASIC, and there is much wringing of hands (not by me, really) that there isn’t a good interpreter for Raspbian on the Raspberry Pi. So when I found X11-Basic — a cross-platform GFA-Basic-like system — I had to take a look.

While I have managed to get X11-Basic demos to run, I have to say it’s not running super well. I’ll show you how to install X11-Basic 1.20 and get it (mostly) running, but it’s a bit rough on the ARM. Incidentally, these instructions also work on Ubuntu 12.mumble LTS on x86.

First, you need to install some (okay, a lot of) packages:

sudo apt-get install libreadline-dev tcsh libncurses5-dev xutils-dev libc6-dev libsdl1.2-dev libtool

Now download and extract the package:

tar xvzf X11Basic-1.20.tar.gz
cd X11Basic-1.20

For X11Basic-1.20, you have to issue an extra command before the standard ‘./configure ; make ; make install‘ sequence:

sudo mkdir -p /usr/local/share/man/man1
./configure
make
sudo make install

This is enough to make a working xbasic interpreter. I made some screenshots of some of the graphics demos —

Screen Shot 2013-03-08 at 16.34.51 Screen Shot 2013-03-08 at 14.59.37 Screen Shot 2013-03-08 at 14.57.21 Screen Shot 2013-03-08 at 14.54.08 Screen Shot 2013-03-08 at 14.49.48As you can see, there’s some screen corruption, but most demos just worked. Incidentally, the Mandelbrot one took almost 1¼ hours to run. Took me right back, that did (or it would have, if I hadn’t been outside bombing about in the slush on my bicycle while it churned away).

In order to see just how fast the interpreter is, I ran the formerly fearsome Personal Computer World Benchmark #8 under X11-Basic. PCW#8 used to bring 8-bit home computers to their knees, typically taking more than a minute to run. Here’s the code, indented a bit and with a timing wrapper added:

	LET start=TIMER
	LET K=0
L30:
	LET K=K+1
	LET A=K^2
	LET B=LN(K)
	LET C=SIN(K)
	IF K<1000
		GOTO L30
	ENDIF
	PRINT TIMER-start
	QUIT

(yeah, GFA-style BASIC isn’t too pretty …)

It takes about ¼s to run. The old BBC B was supposed to take about 50s. By comparison, X11-Basic on a manky old dual-core Atom took 0.04s.

The native compiler xbc seems to work. To make a standalone binary of the above code, you do:

xbc -o PCWBenchmark PCWBenchmark.xbas

The compiled binary runs roughly twice as fast as the interpreted code. Not blazing fast, but a useful increase.

Unfortunately, the bytecode compiler xbbc doesn’t actually do anything on the Raspberry Pi yet. So here I leave it up to you to play with X11-Basic, and see what it can and can’t do.

Too much packaging, Newark

Newark really need to get a handle on their packaging.

I’d ordered a bluetooth adapter for my multimeter. It needs a little doohickey to attach to my meter, which Newark sent out by separate cover. This is how it turned up:

newark boxesSee the little orange thing on top? That’s the part. It’s 70×40×15 mm, and made in Malaysia. It was packed bubble wrap in a sturdy little cardboard box (163×73×43 mm, or 12× the volume of the part). That box was then packed in a very solid box (originally shipped from Penang to Gaffney, SC) measuring  200×200×170 mm; that’s 162x the part’s volume. Finally, that box was inside a third box of 330×245×220 mm, or 424× little doohickeys.

Thing is, the little doohickey is a tough injection moulded polymer part. It could probably be dropped in a padded envelope and survive any mail journey.

We’re going to die out for sure.

New, tall wind turbines are super-awesome, according to REF

If I said that computers got slower with age, you’d look at me as if I were deranged. But REF say effectively that about wind turbines.

My former (nutso) argument goes like this: your 30 year old Commodore 64 is so much slower than the multi-core beastie you’re reading this post on, so computers get slower as they age, amirite …? I can’t actually keep this nonsense up much longer (computers have always been as fast as the market and technology could support), but the Renewable Energy Foundation manage for about 50 pages of statistical gorp in their paper, “Analysis of Wind Farm Performance in UK and Denmark“. And oh boy does the dittosphere like to report on it, like here, here, here, here, and here.

In short, the key graph in the report is this:

ref_graphIf you believe it, it shows a steady decline in wind farm output with age. But thankfully, the good chaps at REF supply all of their data (and also have a bunch of other wind farm stats lying around in easily scrapeable formats; cheers, m’dears!), so I could take a look at their claims. So I made a subset: uk_annual_ncf [ODF], which has:

  1. all the monthly stats collapsed into annual Net Capacity Factors (NCF) for 2003–2011
  2. only the sites that have full details of wind turbine model, rating, installation date, height and diameter
  3. none of the sites that have been obviously repowered, with giant NCF jumps being a giveaway
  4. minor edits to turbines specs on sites I know and likely worked on at some point.

First off, and most blatantly, there’s no correction for annual wind patterns in the REF report. Blustery Januaries are merrily correlated against balmy Augusts, so there’s a lot of noise in the data. Using only annual data for those sites with 9 full years of data aligned everything quite nicely:

NCF by YearNo real trends evident there, except that the wind appeared to have sucked mightily in 2010. So how about if I graph the same data, but plot it by project age at mid-year:

NCF by AgeAnd there it is: a trend pulled from where there was none. It’s not very well correlated, but you could say that it shows a decline in NCF of about 0.6% per year. I wonder where it came from?

There’s one site that gives REF’s game away: Blood Hill, in Norfolk. It’s had 10× 225 kW Vestas V27s on 30m towers running since 1992, but it’s also got a single megawatt-class Enercon turbine on a 65 m tower which was installed in 2000. Here’s how the annual capacity factor looks for both sites:

blood hill yearly dataApart from a slight maintenance wibble in 2007-2008 on the older turbines, the capacity factors track each other quite well. Remember, these turbines are nearly 20 years old at the end of the graph; according to REF, they’d be bumping along at about a third of their original capacity. So let’s graph them by age:

Blood Hill NCF by AgeAha! Here is the secret key (as a certain spider might say). If you compare new, tall turbines against old, small ones you get this false correlation. To show you how much wind turbines have grown, here are the average sizes for each installation year in the data set:

Year Avg Height
/ m
Avg Diameter
/ m
Avg Power
/ kW
Installed Capacity in year
/ MW
1991 32.0 34.0 400.0 4.0
1992 30.3 31.7 343.2 25.1
1993 31.8 35.2 428.0 35.1
1994 31.7 37.0 466.7 15.4
1995 35.0 44.0 600.0 15.6
1996 31.8 40.7 573.6 60.8
1997 32.3 41.3 527.7 34.3
1998 33.2 33.3 363.2 6.9
1999 40.6 45.5 647.1 18.1
2000 39.7 45.5 672.4 49.8
2001 40.9 51.6 963.9 31.8
2002 43.4 55.6 1023.1 26.6
2003 58.3 58.0 1166.7 3.5
2004 51.4 64.9 1593.5 146.6
2005 54.4 64.9 1525.7 346.3
2006 60.9 74.2 1919.5 418.5
2007 63.5 68.8 1753.4 206.9
2008 66.7 78.0 2104.4 662.9
2009 60.6 71.0 1804.4 268.9
2010 69.6 79.4 1987.8 163.0

It’s clear from the table that the height, diameter, and rated power of the turbines installed in the UK have all gone up. Turbines really have got bigger over the years; just look at this old promo slide from Vestas:

vestas-turbine_sizeWind turbines grew immensely; maybe not quite by Moore’s Law, but exceedingly fast for mechanical machinery. So to even compare old turbines to new is exactly like comparing your old Commodore 64 to a current computer: that’s to say, not even wrong.

This is how wind turbine hub height grows by installation year for the sites it can be reliably extracted from the REF data:

Hub Heightor if you want to look at it the way REF does, by age:

Height by Age(I fully expect someone to come out with a report that says “Wind Turbines Get Smaller As They Get Older” … oh wait, REF already did.)

To compound this effect, wind speeds increase with height from the ground. So taller, newer turbines are able to harvest much more energy than shorter, older ones. What’s more, the larger a wind turbine’s rotor, the more swept area it has, so it will have even more energy available to supply to the grid. In a later post, I’ll run a simulation where, with no degradation from a wind turbine’s output, you can fake a decline just by building taller turbines every year.

In short, we can take two things from the anti-wind REF’s report:

  1. There is no gross decline in a wind project’s output with age.
  2. New, tall turbines are super-awesome compared to older, shorter ones.

The sad thing is that REF peddle this deliberately misleading crap, and some of the public believes them. The spectacularly sad thing is that I had to waste my time sleuthing my way through it all.

USB Fart Detector (unfortunately)

It is a truth universally acknowledged, that an engineer in possession of a solid-state flammable gas detector, will shortly make a fart detector with it. I’m sorry, but call it childishness, simple-minded curiosity, or the results of a diet high in polysaccharides, but this is something I have to get out of my system. (It’s okay; I’ll waft the door.)

This all started when our carbon monoxide detector decided it was past its best, and started to emit an ear-splitting shriek. Thinking there might be some cool parts inside, I took it apart. Inside, in amongst the other stuff, I found this:

gas sensor boardThankfully, David Cook of Robot Room had once had the same idea as me (well, minus the puerile bits), and he documented the sensor board very well: Explosive Gas Detector Board. Here are the four pins that you really need to get the thing going:

 Pin # (from left)    Function
===================  ==========
       1              Vcc
       2              /Enable
       3              /Gas
       5              Gnd

Pins 2 and 3 are active low signals. To be typographically correct, I’d write them as Enable and Gas, but that’s hard to do in fixed-pitch ASCII. I can understand why the Gas signal should be active low (think about it; if the Figaro TGS 2611 sensor fails or shorts, it will likely fail to an alarm state, so you’ll still be alive to curse the bloody noise that woke you at 03h00), but the Enable being active low? Dunno.

I was hoping to have presented a little sketch for the Digispark that would have typed something unhelpful every time that gas was detected, but it was not to be. It seems that Macs and Digispark keyboard emulation is a thing of great wobbliness, so I had to resort to an Arduino and a serial connection.

Here’s the code:

/*
 gas_detector - uses board scavenged from CO detector
 
 scruss - 2013-02-18 (unfortunately)
 */

int gas     = 2;               // /Gas line on pin 2
int val     = 0;
int lastval = 0;

void setup() {                
  pinMode(gas, INPUT);
  Serial.begin(115200);
}

void loop() {
  val = digitalRead(gas);
  if (val != lastval) {
    if (val == LOW) {          // LOW means gas detected
      Serial.println("gas");
      Serial.println();
      delay(1000);             // wait 1s for air to clear
    }
  }
  lastval = val;
}

Before you ask, I tested the circuit by briefly hitting the button on a gas lighter. Honest.

I’ll keep working on the Digispark; it’s such a nifty little device, and this is such a worthy project …

A Murder of Crows on your Raspberry Pi with Boodler

Boodler is rather fun. It generates ambient music based on user-defined or downloaded ‘soundscapes’. If you’ve got a modern (HTML5/Opus-capable) browser, you can hear a streaming demo here: http://repeater.xiph.org:8000/clock.opus. It’s using the FM3 Buddha Machine samples in this demo, but it can run lots more: a tree full of crows, a thunderstorm, dripping water, …

It’s pretty easy to run on a Raspberry Pi running a recent version of Raspbian. The only technical glitch I had was that there’s something deeply confused about ALSA sound handling on the Raspberry Pi. I’m sure it’ll get fixed soon, but for now, you have to use PulseAudio. (If you want to read about my ALSA woes, go here.)

The installation prerequisites are simple:

sudo apt-get install pulseaudio pulseaudio-utils libpulse-dev python-dev

Now download and configure Boodler:

wget http://boodler.org/dl/Boodler-2.0.4.tar.gz
tar xvzf Boodler-2.0.4.tar.gz
cd Boodler-2.0.4
python setup.py build

It takes a while to do this, but make sure it does something useful when it’s building the various sound drivers. You don’t want it to say:

skipping 'boodle.cboodle_pulse' extension

If it says that, you haven’t installed Pulseaudio. Go back and check your apt-get line.

Once it’s built, now install it:

sudo python setup.py install

Now test it:

boodler --hardware --output pulse --testsound

Not merely should you get some pleasant tones from your Raspberry Pi’s audio, but you sound get some informative and non-threatening terminal output. Mine looks like:

Boodler: PulseAudio sound driver.
 PulseAudio library: 2.0.0.
 Sample rate is 44100 fps.
 Samples are 16-bit little-endian.
 Buffer size is 32768.
 21:37:46 (root) Running "Boodler test sound"

If that works, let’s get those crows a-cawin’. Download the soundscapes you need:

boodle-mgr install http://boodler.org/lib/org.boodler.old.crow.1.0.boop
boodle-mgr install http://boodler.org/lib/com.eblong.zarf.crows.1.0.boop

and run it:

boodler --output pulse com.eblong.zarf.crows/ParliamentOfCrows

Crows everywhere!

I really like the Buddha Machine samples. It’s quite big (> 80 MB), so this next set will take a while to download:

boodle-mgr install  http://boodler.org/lib/com.azulebanana.buddhamachine.1.5.1.boop
boodle-mgr install http://boodler.org/lib/com.azulebanana.buddhaagent.1.5.1.boop

It’s worth the wait:

boodler --output pulse com.azulebanana.buddhaagent/ChangingLoops

Boodler has tons of options, prebuilt packages, and instructions to build your own: Boodler Documentation.

One thing I’ve tried to get working, but failed, is streaming from Boodler via icecast. Sure, I can install and run it, it’s just that the results are, um, undesirable. If you want to have a play, here’s how to install icecast:

sudo apt-get install icecast2 ices2 libshout3-dev

Icecast will configure itself, and ask for a couple of passwords. You’ll have to rebuild and reinstall Boodler for it to catch the new configuration. You can then try streaming:

boodler --output shout --define shout-password=mypassword --define shout-mount='/boodler-buddha.ogg' com.azulebanana.buddhaagent/ChangingLoops

If you open a web browser at this address http://raspberrypi:8000/ you should see a config page listing your boodler-buddha.ogg stream. Click on the M3U link next to it, and your streaming music player should start making a joyful noise …

… except in my case, something went very wrong, and it started to produce industrial ultra-glitch nightmare noise: boodler-streaming_test-fail. I’m sure it’s fixable with some tweaking, but I’m not there yet.

X10 for Raspberry Pi on the Cheap [North American Edition]

Now I’ve got my X10 system running and know its limitations, I could have saved a wheen of money not buying stuff I don’t need. Our house appears to have been wired by an, um, spirited amateur, so powerline signalling is of limited use. Thankfully, the tiny and cheap X10 FireCracker CM17A (warning: too many flashing GIFs at this link!) can be driven from heyu [previously]. You can score these on eBay for under $10, and all you need is a serial adapter to drive them.

Leviton X10 controller - cheap!The really cheap bit in my system was discovered in Active Surplus. I found a case of Leviton “Plug-in Frequency Transceiver Modules” for $4/each. One was out of its case, and wouldn’t you know it, it’s the same as a RR501 module, which typically retails for about $30. Sure, these are old stock and are a nasty beige colour, but they provide a way of switching a two-pin appliance. They can also relay remote commands from RF to wired controls.

The only X10 controller I can’t get to work with the Raspberry Pi is the CM19a USB PC Transceiver. I suspect it draws a bit too much power to run from a Raspberry Pi, as it makes the machine unresponsive if it’s plugged it. Running from my bench setup it works fine with the mochad driver, but no dice with the other machine. The CM19a reads wireless RF X10 commands, and it would be useful if I’d added a motion sensor. As is, I’ll stick to the lights going on and off.

(Incidentally, this is the “North American Edition” because X10 RF controls are completely different in Europe, and none of the above is useful to you. Yeah, I know this article is the equivalent of PC Load Letter to you; sorry.)