GRG's Miscellany

Success!  I have completed step 1 of my robotic world domination plan! I now have a laptop with Eclipse and leJOS installed, which can control my newly-flashed Lego Mindstorms NXT brick! The tutorial is actually really easy to follow.  I used Linux, which required me to manually set the control brick into 'firmware updating mode', but that was a piece of cake. Setting up Eclipse was also fairly straightforward, following the instructions here . The only gotchas I encountered were: - Setting up udev rules to allow me to access the control brick via USB.  Solution: After creating the rules file, remember to add yourself to the 'lego' group and restart the PC! - Connection to control brick kept failing in 'PC' mode.  I could upload a program and run it from a 'leJOS NXT project', but not have the PC run an application that remote controls the brick.  Solution: Needed to install it onto a 32bit OS (thankfully I had a laptop which fit the bill...

Batman: Arkham Asylum is a great game.  It has made me feel like a brutal martial arts expert, a stealth-killer, an elite techno-hacker - all the things that Batman is.  To my mind, that's what a game is for: it makes you feel like you're another person, in another universe so you can experience their story. However, the game has reached a shelf-point for me.  I hate rage-quitting, but that's what it made me do.  I'm not sure if I'll go back to complete it.  I'll explain why. Two types of battle which work really well: Firstly, fighting off a mob of henchmen, with the combo and counter moves.  It makes me feel like Batman: I feel anxious to avoid being hit, I weigh up the individual opponents and choose which to take out first, I spread my attacks between multiple opponents and choose a variety of special moves to help.  I also like that it slows down time a bit when you need to counter, so you have time to realise it and press the appropriate b...

Seriously annoying exception in WinDeviceDriver constructor because of 'transparent' code accessing 'security critical...' yada yada yada.  Turns out .Net 4.0 has some trumped up security code so Microsoft can break everything. Anyway, the workaround is this: In the AssemblyInfo.cs file of the assembly containing the offending class (OpenTK in this case), add: [ assembly: SecurityRules ( SecurityRuleSet. Level1 ) ] et voila!

Solved an odd problem today. Problem 1: File locking My samba share directory on my ubuntu box has an nfs mounted directory within it. When copying files into it from Linux, everything was fine. However, Windows complained of error number 0x80070021 (something about another process locking a portion of the file).  It turns out Samba was trying to lock the file again once nfs had got its hands on it. Solution: in smb.conf, under [global], add 'strict locking = no' and the problem disappears! Problem 2: File permissions Linux coped perfectly fine already, possibly because of the file_mode=0777 and dir_mode=0777 that I'd added to fstab.  However, Windows failed to create the files with the correct permissions. Solution: under [mediashare], add 'create mask = 0775' and the permissions are right under Windows too!

It all works fine until you try to run it. :( It complains that it can't load the LWJGLException class (even though lwjgl.jar is clearly in the classpath). But it turns out, the problem was that java couldn't find the native libraries. Here are the command lines to build: javac "%f" -cp '.:/usr/lib/jvm/jdk1.7.0_04/lib/*' and to run: java -cp '.:/usr/lib/jvm/jdk1.7.0_04/lib/*' -Djava.library.path=../natives "%e"

I've been concerned for a while that my cardboard case doesn't properly support the weight of my graphics cards. I've experienced persistent freezes and spontaneous resets under Ubuntu, and thought it was a driver issue. This morning, I had crashes in Ubuntu 10.04LTS, 11.10 AND Windows 7.  When I nudged one of the graphics cards up and rebooted, Windows 7 was fine. I have now added more support for the graphics cards.  11.10 still freezes.  So far 10.04LTS still going strong.  Haven't tested Win7 yet.

Fix here: http://ubuntuforums.org/showthread.php?t=1861865