Here's a quick intro to what I'm hacking on at university. This is a new omnidirectional robot platform we got in the lab. It's controlled via CanOpen-over-EtherCAT (which is a realtime Ethernet protocol "extension", more or less). As we don't want to deal with any of the Windows software that's usually used for such stuff, we're employing the IGH EtherCAT Master (r1549) implementation (GPL/LGPL) on Linux and it works quite nicely.
I hacked together a few shell scripts that invoke the ethercat command line tool with certain parameters to control the motor velocities "by hand", which then soon turned into a "dancing" demo of the robot ;-)
See http://www.youtube.com/watch?v=n_vF4NK26fM for the YouTube video of the dancing bot. It's just a quick (hardcoded) hack for now, there's lots of room for improvements, of course (e.g. detect baselines of random music you throw at it). The demo in the background is the fantastic Masagin by Farbrausch.
I've also hacked up a small Python script to control the robot with a Wiimote (using cwiid on Linux), which also works quite nicely. I further plan to make a small program for controlling it via a 3D mouse or the like in the future...
The longer-term plan for the robot platform is that it'll get a "backbone" and two very nice robot arms for grabbing stuff etc.
This weekend I had the pleasure of visiting my friend Kike in Iru a, a
city I really like but had not been able to visit in five years. I
spent three days with him, after a really awful Bilman trip during
Friday night.
The first thing that happened on Friday morning was quite unexpected. I
went out, crossed a pair of streets to get to Carlos III, and going past
the corner I found myself surrounded by all kinds of policemen: red, blue,
green and yellow. There were press reporters all over the place, with TV
and photo cameras ready to record something big. What the hell? I looked
around, and there it was: a huge blue sign read Populares de Navarra,
and Mariano Rajoy was seconds away from getting out of the new PP headquarters
in Nafarroa. With a few dozen policemen looking at me in suspicion, and
realising my current hair dress wasn't the most appropriate for that scenario,
I decided to disappear as quickly as possible.
Populares aside, the weekend was really productive. I had a great
time trying to find the places I visited 9 and 5 years ago. It was sad to see
the fantastic Iru ako Gaztetxea turned into an iron building
surrounded by old, traditional houses in the centre of the city. With Kike,
I had enough time to learn more about the origins of Iru a and the three
cities from which it originated, and visit the Ciudadela.
On Saturday, Kike, Ana and I went to have some fun on a snowy day around
Orreaga and had dinner in a small town around the area, maybe Lintzoain? I'm
afraid I forgot due to the mix of basque names in my head. We had dinner
in lo viejo, where I spotted a poster of
Solidari@s con Itoiz for the Itoitz
hustu arte campaign, a copy of which I unsuccessfully tried to get in several
places in the city.
On Sunday, Kike and I took a bus to Donosti, and I travelled across the
most beautiful highway I've seen. But of course, that was from my
perspective seated in a bus. I can imagine the Leitzaran highway project must
have been greatly contested by the people of the tiny towns nearby. The spoiled
valleys and views must have been really impressive in the past and seem now
irreversibly ruined by a scar and holes through the mountains.
This was my first visit to Donosti, which held its annual Marathon, and
were lucky to meet our friend Rub n when he was around kilometre 25 of his
race. He managed to finish under 2:50, which was a bit better than what he
aimed for in his first Marathon. Well done! The weather was horrible, and our
visit to La Concha, the old harbour and the Casco Viejo was
short, we were freezing and getting our feet wet.
While I visited Donosti for the first time, Mikel Laboa, one of the most
respected singers in the basque culture, was ebbing away. Laboa's songs always
give me goosebumps, even if I need to read a translation for the basque lyrics.
Many will remember his music from Julio Medem's documentary,
La pelota vasca, featuring
Txoria txori, which has become a symbol of basque culture over the years.
Youtube has quite a few videos, and I'd recommend watching
Txoria txori,
Gure bazterrak,
Lili bat or
Baga biga higa
performed by the Orfe n Donostiarra to name a few.
Mikel Laboa, goian bego.
I knew for a long time that rails is somewhat fun to work with. The
first time I read something about it, I went to check it out, and kindof
liked the idea. Web development really isn't my cup of tea, so I didn't
do anything with rails; but really, the idea made somewhat sense to
me.
It's unfortunate that the implementation is such a piece of
crap. Luckily I don't have to deal with it firsthand, but the stories I
hear and read everywhere speak for themselves. I won't enumerate them
all; but in case you're not familiar with them, the Debian Ruby team has
a pretty clear explanation
on their website. In addition to complaints by packagers, I also hear
that many ruby developers recommend that you install gems inside the
project you're running (or that you ship your software in such a way
that it includes those libraries as part of your source). Oh, the
horror.
Now, however, they've really topped it. Via Koen's
blog, I found some
other page that contains this:
Now, in theory, to update to the latest version of RubyGems, you just need to runSeriously. This is why we have distributions, packagers, and, really, people spending a whole shitload of time making sure everything works together nicely. This is why there is Debian, RedHat, CentOS, Mandrake, SuSE, and whatever. Me touching rails? Not with a 10-foot pole. Not if you pay me a million, in any currency. Stay away from my system!
sudo gem update --system
But - depending on what version of RubyGems you have installed, running that command may lie and tell you that you have nothing to update. If you re currently on RubyGems 1.1 or 1.2, you need to run a different set of commands to update RubyGems:
sudo gem install rubygems-update
sudo update_rubygems
I only start believing I'm visiting some new place when I've finally spent
way too many hours looking at flight websites in an attempt to find a flight
that is slightly cheaper than the only option everyone else is offering you,
and after a few days prices have gone up enough so you give up and end up
buying.
And, two weeks ago, I finally did. Barcelona-Istanbul means
the third chapter of the unplanned saga Chistmas in Islam . Two years ago
I started 2007 visiting
Tunisia,
and last year we enjoyed a 10 day trip around the South of
Morocco,
which was absolutely fantastic (and I've still haven't blogged about).
This year I'll be discovering Istanbul, Cappadocia and other parts of
Turkey with Maria. The idea is to try to avoid visiting too many places
in a rush, and follow the good advice of our Moroccan friends, La prisa
mata, amigo . We have plenty of days to explore Turkey's secrets, but
I want to be able to enjoy them, and avoid being in a constant hurry.
As always, I'll be glad to get suggestions on must not miss places or
things, and advice on how to move around, where to stay, what to do or what
not to do is extremely welcome. I'm totally looking forward to this,
after I missed this years's GUADEC!
Way back in mid-late May, I switched keyboard layouts from standard US QWERTY to Colemak. I’d played around with the layout a bit before that and thought it seemed pretty solid, but it hadn’t been a good time to switch then. (I did, however, snag the idea of remapping Caps Lock to Backspace from that early trial though, and to this day that’s probably the most annoying thing about typing on QWERTY, because I associate Caps Lock with Backspace on both layouts now. Anyway.) This time, however, I strategically timed it to coincide with the end of classes, so I had no assignments due and could make a fool out of myself during the first few days of my summer job. Smashing success.
It only took a couple days to get past the point of extremely frustrating slowness. Two weeks in I was up to 40wpm, which was about the point where I stopped noticing that I’d taken a backwards step in typing speed, as it didn’t really hinder anything I did on a regular basis. By the end of the summer I was back up to the same speed as I’d been prior to switching (around 75wpm). I didn’t really do any typing lessons after the first few days, as I found just doing whatever I would normally do on a computer much more interesting.
The biggest hurdle after the initial adaptation of actually being able to type on the layout was, for a command-line lover like myself, dealing with “hjkl” not being a convenient way of navigating around in console apps like mutt, vim, aptitude, and less. After a bit of experimentation, I stole an idea from this page and started adapting my dotfiles to make these programs use ne for jk and st for hl, and that seems to be working out well. The worst key that this clobbers in general is n, but it’s pretty easy to remap that to QWERTY’s n, which is easy to remember and is the hardly-used k on the Colemak layout.
For any interested others, I’ve thrown the relevant dotfile snippets up here. I’d been putting off blogging this because I wanted to finish setting up dotfiles/homedirs-in-git la Joey Hess beforehand, but I figure I’ll never actually get it done if I keep using that excuse. For mutt, the given snippet goes in your .muttrc (or whatever you source keybindings into your muttrc from). The same goes for vim. Aptitude keybindings go in .aptitude/config. For less, it’s a little more arcane: first you stick your keybindings in .lesskey, and then you run the command lesskey. I also remapped screen’s escape key to ctrl-t.
Why not Dvorak?
Dvorak seems to be the most well-known QWERTY alternative around, so why didn’t I switch to that if I wanted something better? I did try Dvorak first, but the incredibly uncomfortable combination of ls on the right pinky was a complete deal-breaker. I also found it very slow-going to try to adapt to Dvorak after typing on QWERTY for years. The Colemak FAQ has some more notes on Dvorak deficiencies that it addresses.
Overall, I’ve found typing on Colemak to be remarkably lacking in anything that particularly bothers me. I still type on QWERTY a little, but mostly just for login prompts on Athena workstations and the desktop machine in my room which my roommate sometimes uses. I have to glance down at the keyboard when typing on QWERTY to get it back in my head, but generally I only need it for a few minutes anyway and it’s no big deal. As long as I glance down occasionally I can still maintain a speed level well above that of frustration. On the plus side, this means that if I look at the keyboard when typing normally in Colemak, I get screwed up because I start thinking in QWERTY. So it’s good touch-typing reinforcement in general.
mplayer -vo null -ao pcm:fast input_video_file
sox audiodump.wav --rate 32000 -1 --channels 1 audiodump_small.wav vol 0.9 ditherspeexenc --denoise --vbr --dtx audiodump_small.wav output.spx
oggenc --downmix --output=output.ogg audiodump.wavlame -mm audiodump.wav output.mp3
One of the things I wished for last month was a decent cooperative pay-as-you-go mobile phone service. About the same time, Ofcom started a social web consultation about mobile phone services. Now there’s an excellent presentation by Vivian Woodall, Chief Executive of The Phone Co-op that was given to FCS’ Comms Provider 08 event.
Ofcom’s Mobile citizens, mobile consumers: the importance of mobile suggests the idea of re-regulating is “controversial”. I’ve left a comment there that asks why. It seems obvious to me that UK mobile phone service is currently a market for lemons - useful independent measurements are few and far between, there are no trial periods and it’s often expensive to change provider. Maybe it’s different in the big cities.
Meanwhile, real complaints like An Orange-coloured hell, T-Mobile is the new Orange.. and Cancelling a Three mobile contract FAIL keep appearing with depressing frequency.
Just how big does the FAIL need to be before Ofcom actually intervene?
One of the things I wished for last month was a decent cooperative pay-as-you-go mobile phone service. About the same time, Ofcom started a social web consultation about mobile phone services. Now there’s an excellent presentation by Vivian Woodall, Chief Executive of The Phone Co-op that was given to FCS’ Comms Provider 08 event.
Ofcom’s Mobile citizens, mobile consumers: the importance of mobile suggests the idea of re-regulating is “controversial”. I’ve left a comment there that asks why. It seems obvious to me that UK mobile phone service is currently a market for lemons - useful independent measurements are few and far between, there are no trial periods and it’s often expensive to change provider. Maybe it’s different in the big cities.
Meanwhile, real complaints like An Orange-coloured hell, T-Mobile is the new Orange.. and Cancelling a Three mobile contract FAIL keep appearing with depressing frequency.
Just how big does the FAIL need to be before Ofcom actually intervene?
)
I wish everyone a happy Diwali and nothing but good fortune and prosperity in the new Gujarati year called Sharvari (V.S. 2065)
This year the local mandirs got wise and lobbied the city for permission to hold a firework display however we had horrible weather today so we didn't go. I had already prepared my own stash of fireworks anyway so we enjoyed them at home.
On the presents front, I got a much needed woollen hat, another tulasi plant (lets see how long before I kill this one.) and a gift certificate for audiobooks which I used to get "Slaughterhouse 5" by Kurt Vonnegut, "Naked Lunch" by William S. Burroughs, and "A Clockwork Orange' by Anthony Burgess. And of course all the sweets I could eat.
Once again I crushed all beneath my booted toe at Hungry Hungry Hippos.
Until Eric S. Raymond turns up in 1990 with this: CRACKER (krak r) n. One who breaks security on a system. Coined c. 1985 by hackers in defense against journalistic misuse of HACKER,Does anyone know the answer? Have any thoughts? I penned a few comments below as well but won’t repeat them here. His comment as well as Nona’s reminded me of this brilliant shirt crafted by Mathew Garret.
see definition #6. And I ve never heard before of this; so I presume ESR himself decided that people who break into systems are now called by a name which some other group had already applied to themselves. I anyone has some documents referring to this kind of crackers from before 1990 and not from ESR, I d be happy to hear of. And I ve got plenty of documentation on the other crackers , those who crack copyprotection, from 1980 onwards
I decided to get an electic bike when my car died. Couldn't
quite stomach buying a new gasoline vehicle at this point in time, didn't
really feel like another used car, and the available electic cars are still
too new/expensive/hard to find. While there are some neat NEVs that are not
too expensive, they're too limited to be worth my money, and electic bikes
fit into the same general niche. (So do electic scooters, but I didn't want
to spend that much money on an experiment..)
My first try was a disaster. I was thinking that a large cargo capacity
would be a good thing, so I gravitated toward trikes. However, the one I
tried turned out to be a lemon in several ways, and suffered a catastropic
and dangerous controller burnout. So I learned that this electic bike
industry is pretty rough and ready with a lot of junk to avoid. I also
learned that I don't enjoy riding trikes.
The second try was a R Martin LX1, which my dad
had researched. I got it yesterday, and have ridden it some now, and I
agree that it's a good one.
As a bike, it's well built, has a good back disc brake and decent front
brake (will be better once I bring it to a bike shop to adjust it better),
has a good derailer, and rides well. I'm no expert but it seems about as
good as the bike I used to commute with, though the frame is a bit heavier.
(IIRC, it was also at least $200 cheaper than that bike!)
On the electic side, it has a relatively small and light lithium ion
battery; the motor is mounted in the hub. It's strong enough to go up hills
on its own if you really want it to, but you will end up pedaling to
assist, which is good.
I'm undecided whether the six gears are enough ... Seems like I might want a
faster gear, to be able to assist the motor more at high speed. I haven't
wanted a lower gear yet, but I've not tried to do any hills without the
motor's help.
The electic controls are ok, but not perfect. I worry about accidentially
twisting the throttle, although it has to be turned quite far to engage the
motor.
Ideally, the pedal assist would turn the motor on exactly when you pedal,
and porportionally to how hard. Instead, there'a a lag, and doesn't care
how hard you pedal. This can present problems coming up to an intersection
or other hazard, where pedal assist kicking in can unexpectedly be more
speed than is needed. Seems a waste to have to brake to cut the assist off.
The motor is audible when accellerating, and especially complains when
trying to get me up a hill on its own. At speed, or if given a human power
assist, it's quieter than the chain, if not silent.
So there's room for improvement (and this would be a fun thing to do some
hacking on to improve its response), but it's still a lot of fun. I'd
forgotten how much I enjoy riding a bike and getting a nice workout. And
it's especially nice to go up a hill pedaling only as hard as you like, to
be able to accellerate quickly without standing on the pedals, and to be
able to "coast" a long, long, way.
My workmate Pep was kind enough to drive me home back from work today.
Ideally I would have cycled home as always, however today my bike was stolen
again. It's not the
first time or
the second one, not even
the third. My
red Orbea is the fourth bicycle that gets stolen since cycling became
my primary means of transportation more than 10 years ago.
Sadly, in Val ncia, the norm is to get your bicycle stolen every few years,
if you need to leave it unattended during work hours. In this case, its even
worse as the bike stays inside the University
campus all day, supposedly guarded by security personnel, and in a place where
dozens of people tie their bicycles, with constant presence of the people
who work in the CPI complex.
This bicycle was given to me by Cherry when she left Val ncia, just a week
after the previous one had been stolen. She had bought it to cycle around
the Valencian mountains during her 6 month stay in Clara's lab, and was
immensely kind to give it to me when she learned what happened to mine.
I planned using the mountain bike during the long 9 d'octubre
weekend, but I'll have to see if someone can lend one for this year's cycling
trip.
It seems I'll have to resort, again, to my 29 year old Laida to
move around Val ncia, which will need an extensive repair of both wheels and
brakes. Time to visit Benimaclet's bicycle workshop.
Myself and a colleague were both getting Joe-jobbed yesterday. I had an easy time telling Exim to reject mine at SMTP time, but the colleague receives mail on our only Plesk server, so it’s using qmail. I’ve noticed before that qmail admin tools are primitive and incomplete, so I looked for the appropriate rocks to bang together to put this fire out. (I think I just sprained a metaphor.)
My best attempt so far is to edit the user’s .qmail file to start with a pipe to a command that exit 100s if it detects an error for an email which the user obviously didn’t send (wrong email client or whatever). qmail understands code 100 as a hard error, so I think that should generate an SMTP error, but I didn’t figure out from the logs whether it was SMTP-time or later and my testing was inconclusive. I suspect Plesk will remove my pipe when the user next edits their email account, too. How do qmail/Plesk users not drown in spam?
In related news, I’ve started getting “Challenge Response” emails from users of Merak Mail Server Software for emails I never sent. I’m answering the challenges so that challenge-response users get spam if their server spams me. Challenge-response is evil - I don’t want spam from your mailserver just because you accepted spam that said it was from me. If you are using Merak Mail Server Software, change away now!
One of my current anti-spam tactics is to read my email in batches (which Suw suggests is a good idea) and group messages which look “similar”. Very similar messages appear for very few reasons: people resending messages, mailing list threads, stuff from spam-nets and a few others. Apart from spam-nets, most of the others match one of a few keywords. My current method of doing this is part-automatic and part-human. Are there automated anti-spam tools which exploit this local similarity? I think DCC used to include this idea, but then there were software patents and hoo-ha and I stopped paying so much attention.
Finally, a small discussion has broken out in the comments of Is Yahoo Now Even Worse On Spam? about whitelisting and business-critical uses of free webmails.
A common trait of virtually all of the media in Mexico -and, as far as I have been able to see, in Latin America- is the push for society to be afraid. The government and the media (which go hand-in-hand, mainly due to a series of favors owed to each other - currently stemming from the government's illegitimacy and lack of trust from the general population) wants us all to think the country is as violent and as dangerous as it has never been before.
In an hour the online part of this combined embedded+fai meeting in Badajoz in Extremadura, Spain, will sadly be over, but the sadness will hopefully be compensated by good food (yes, the food at the last dinner was great) and more fun! To me it were three intensive days (plus some two half days of intense travelling) which were really productive. This post is a summary of what I did here, to document how useful these meetings are. I'm only one person out of 18, who did some Debian work here, much more stuff was done, most of it I probably didnt even notice, as 14 people where working on embedded stuff, which I mostly ignored... ;-) That said, I think it was still very nice to have this meeting together, a.) because I'm quite interested in embedded stuff and b.) because the embedded crowd is a fun one to hang around with! Next.