Monthly Archives: March 2013

JMyron – unsatisfied link is now satisfied

I was putting JMyron on a new machine, to use in Processing on Windows 8, and kept getting this:

Exception in thread "Animation Thread" java.lang.UnsatisfiedLinkError: C:\Program Files\processing-1.0.4\libraries\JMyron\library\JMyron.dll: Can't find dependent libraries
     at java.lang.ClassLoader$NativeLibrary.load(Native Method)

Well, I used Process Monitor to see what was going on, and spotted a load of failed attempts to open MSVCP71.dll during sketch startup.  I tracked down a copy of that C library (msvcp71.dll and msvcr.dll), dropped them into my system32 dir and hay bingo, works.  Process monitor is ace.

I had already installed the C++ 2010 redist.  I guess JMyron needs some extra sugar.

 

Installing OS over PXE on machine without USB/optical drive

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I got a little second-hand Dell D430 laptop to use for my upcoming polargraph show. I’m actually really impressed, it’s a dinky little thing.  No optical drive however, and installing an OS from a USB memory stick didn’t seem to work.  So I’ve done it over the network, and it even seems to work.

PXE (Pre execution environment) is the method, and this is a way of booting over LAN.  Hit F12 on the POST screen and then boot from NIC.  There needs to be a server on the network with TFTP running on it, to dish up the necessary files.  This is hard, but there is a nice little app called SERVA that handles the TFTP/DHCP stuff, because I don’t know how to.  Anyway, I followed the instructions on this site and windows 8 is winging it’s way onto my new old machine.

Issues:

I initially tried putting the windows 8 disk in and symlinking to it instead of copying the files into the TFTP source folder.  That worked up to a point, but the installation failed.  I think it is because SERVA needs to add some files to the windows installation to customise it for this method, and obviously that can’t work if it’s read-only (on a CD).   So actually copy them over, or at least make sure they are somewhere that is writable.

CV on Raspberry Pi

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OpenCV is a pain.  I guess I’m just being a dolt, but I can’t get it working.

I want to run a piece of software on my pi that will run my slow photo booth at the upcoming Edinburgh mini maker faire.

SimpleCV – http://www.raspberrypi.org/phpBB3/viewtopic.php?t=36348&p=305689

Issue with getting lots of VIDIOC_QUERYMENU: Invalid argument and then a bunch of “Select Timeout” messages:

from http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=11745:

You can not edit the binary uvcvideo.ko file directly. I advise not trying to compile it yourself. It’s not worth the struggle. You can try various options temporarily on the fly. Attach your webcam, the driver module should be loaded and shown by

CODE: SELECT ALL
lsmod

. Then you unload the module using

CODE: SELECT ALL
rmmod uvcvideo

. Afterwards you can reload the module with something like

CODE: SELECT ALL
modprobe uvcvideo nodrop=1 timeout=5000

. Fiddle around with the settings.
You can make a set of parameters permanent by editing the file /etc/modprobe.d/modprobe.conf . For the above settings, simply add a line saying

CODE: SELECT ALL
[code]uvcvideo nodrop=1 timeout=5000[/code]

.