Unable to initialize com.mathworks.mwswing.MJStartupFatal Error on startup: Failure loading desktop class

or

… Java is not currently available

Here is the way I resolved the issue on my Debian Lenny :

I installed the JDK from the Oracle’s download page (following the instructions). I chose the directory  /usr/lib/jvm/ for the installation.

Then I created a symbolic link for Motif (as root) :

ln -s /usr/lib/jvm/jdk1.6.0_24/jre/lib/i386/motif21/ /usr/lib/jvm/jdk1.6.0_2/jre/lib/i386/motif12

And finally I set the environment variables :

export MATLAB_JAVA=/usr/lib/jvm/jdk1.6.0_24/jre/

export AWT_TOOLKIT=MToolkit

That’s all. Now I am able to launch Matlab :

<matlab_directory>/bin/matlab

Almost the same functionality but a little refactorized and bug-fixed.

Any feedback will be wellcomed.

I recommend nibble’s fork of dmenu that fixes a problem showing big selections:
$ hg clone http://nibble.develsec.org/hg/dmenu_nibble/

You can easily adapt dclip to your system by creating keybinds to its ‘copy’ and ‘paste’ commands.

For example in dwm, in order to copy with M+C+c and paste with M+C+v  you can add the following in your config.h:

/* commands */
static const char *dclipcmd[] = { "dclip", "paste", "-fn", font, "-nb", normbgcolor, "-nf", normfgcolor, "-s    b", selbgcolor , "-sf", selfgcolor, NULL };

and in the keys[] section:

{ MODKEY|ControlMask,       XK_c,           spawn,          SHCMD("exec dclip copy") },
{ MODKEY|ControlMask,       XK_v,           spawn,          {.v = dclipcmd } },

Hope you will enjoy it.

Run the script while playing your media. Few seconds after each fully-loaded song/video you will listen a beep indicating that the file has been saved, in that moment you can “jump” to next media.

As an example, for a YouTube playlist called “funny” you can run the script like:

$ tmpmedia_rec.sh funny flv

and the files will be saved in the destination directory as: funny_<number>.flv

You can configure the script parameters at first lines of it.

The best points of this programs in my opinion are:

1. Speed adding new disks (just a tree command and a gzip compression)

2. Size of the catalog file: For example, a catalog with 6 dvd’s stored containing 22500 files distributed in 2608 directories has a size of 290K

3. Portability of the generated catalogs. Independence of them from the cataloguer (plain text file browseable with any text editor)

And, of course, that it’s free software.

The options of this cataloguer are the following:

tecnoprawn@blog:~$ cataloguer
Usage: cataloguer </path/to/catalog.gz> <option> [parametes_of_the_option]
OPTIONS
Disk:
    -a <path/to/disk> <disk_name>       Adds a new disk to the catalog
    -d <disk_name>                      Deletes a disk
    -i <disk_name>                      Shows disk information (number of files and
                                        directories, size)
    -c <disk_name>                      Lists the content of the disk
    -r <old_name> <new_name>            Renames the disk
Catalog:
    -L                                  Lists all disks in the catalog
Search:
    -f <name>                           Find files and directories
    -F <name>                           Find only directories
cataloguer -?                           Prints this help

Any comment, patch or bug report will be apreciated.

Contents:

    0. Kernel
       0.1. Needed Kernel Modules
       0.2. Configuration
    1. CPU Frequency Scaling
    2. Suspend to RAM
    3. Suspend to Disk
    4. Acpi Events: Power & Sleep buttons
    5. Multimedia Keys
    6. Xorg.conf
       6.1. Synaptics Touchpad
       6.2. 1280x800 Resolution
       6.3. DRI (Direct Rendering Interface)
    7. Wireless Card (ipw2200)
    8. Saving Power/Battery
    9. External VGA
   10. Other Issues (PCMCIA, Wired LAN Card, Modem, Card Reader)
   11. Known Problems
      11.1. Fan
      11.2. Fn-keys Pictograms 
      11.3. Button Lid
   12. lspci -vvnn

0.1) NEEDED KERNEL MODULES

Module                  Location                                Symbol
------                  --------                                ------
intel-agp               drivers/char/agp/intel-agp.ko           AGP_INTEL
intelfb                 drivers/video/intelfb/intelfb.ko        FB_INTEL
shpchp                  drivers/pci/hotplug/shpchp.ko           HOTPLUG_PCI_SHPC
uhci-hcd                drivers/usb/host/uhci-hcd.ko            USB_UHCI_HCD
ehci-hcd                drivers/usb/host/ehci-hcd.ko            USB_EHCI_HCD
snd-intel8x0            sound/pci/snd-intel8x0.ko               SND_INTEL8X0
snd-intel8x0m                                                   SND_INTEL8X0M
iTCO_wdt                drivers/watchdog/iTCO_wdt.ko            ITCO_WDT
intel-rng               ?? (INTEL RANDOM NUMBER GENERATOR)      ??
piix                    drivers/ide/pci/piix.ko                 BLK_DEV_PIIX
i2c-i801                drivers/i2c/busses/i2c-i801.ko          I2C_I801
b44                     drivers/net/b44.ko                      B44
ipw2200                 drivers/net/wireless/ipw2200.ko         IPW2200
yenta_socket            drivers/pcmcia/yenta_socket.ko          YENTA
firewire-ohci           drivers/firewire/firewire-ohci.ko       FIREWIRE_OHCI
sdhci                   drivers/mmc/host/sdhci.ko               MMC_SDHCI

0.2) CONFIGURATION

Here it’s my .config file for the Linux kernel version 2.6.25.9 that I use on this laptop. You can use it as a starting point adding/removing features.

You must have SpeedStep activated on BIOS.
In the kernel you must select acpi-cpufreq (X86_APCI_CPUFREQ) as well as the governors you want to use (conservative, ondemand, performance, etc.)

Precompiled kernel Debian packages have this features working good.

The cpufrequtils package makes easier inspecting and setting the CPU frequency (otherwise you can manage it from sysfs or procfs).
Tip: When running high CPU usage processes, if you aren’t in a rush and you prefer wating more than heating too much your processor you can do something like this:

cpufreq-set -u 1.07G

Works out of the box with 2.6.25.9 kernel although there are problems to wake up using previous kernel versions.

I made an alias to enter into suspension mode:

delta@sr50:~$ cat /root/.bash_alias|grep s2ram
alias s2ram='echo -n mem > /sys/power/state'

3.) SUSPEND TO DISK

delta@sr50:~$ cat /boot/grub/menu.lst |grep vmlinuz-2.6.25.9
kernel          /boot/vmlinuz-2.6.25.9 root=/dev/hda2 resume=/dev/hda4 vga=791 ro
kernel          /boot/vmlinuz-2.6.25.9 root=/dev/hda2 resume=/dev/hda4 vga=791 ro single

To enter in suspend-to-disk (hibernation) mode:

delta@sr50:~$ cat /root/.bash_alias|grep s2disk
alias s2disk='echo platform > /sys/power/disk; echo disk > /sys/power/state'

POWERBTN

delta@sr50:~$ cat /etc/acpi/events/powerbtn
# /etc/acpi/events/powerbtn
# This is called when the user presses the power button and calls
# /etc/acpi/powerbtn.sh for further processing.
event=button/power
action=/etc/acpi/actions/powerbtn.sh

delta@sr50:~$ cat /etc/acpi/actions/powerbtn.sh
#!/bin/sh
echo platform > /sys/power/disk; echo disk > /sys/power/state

SLEEPBTN

delta@sr50:~$ cat /etc/acpi/events/sleepbtn
event=button/sleep
action=/etc/acpi/actions/sleepbtn.sh

delta@sr50:~$ cat /etc/acpi/actions/sleepbtn.sh
#!/bin/sh
echo -n mem > /sys/power/state

NOTE: I don’t link s2ram to acpi/button/lid because this “button” doesn’t work properly, see “Known Problems” section.

In the configuration file ~/.Xmodmap you can assign functionalities to the own keyboard keycodes. By example, the keycodes of Mute, Lower_Volume and Raise_Volume buttons are 160, 174 and 176 respectively.

delta@sr50:~$ cat .Xmodmap
keycode 160 = XF86AudioMute
keycode 174 = XF86AudioLowerVolume
keycode 176 = XF86AudioRaiseVolume

Possible functionalities are listed on /usr/include/X11/XF86keysym.h

delta@sr50:~$ cat /usr/include/X11/XF86keysym.h |grep "Volume\|Mute"
#define XF86XK_AudioLowerVolume 0x1008FF11   /* Volume control down        */
#define XF86XK_AudioMute        0x1008FF12   /* Mute sound from the system */
#define XF86XK_AudioRaiseVolume 0x1008FF13   /* Volume control up          */

We should load the configuration on boot load. We could do this, by example, adding a line to the rc.local file, this way:

delta@sr50:~$ cat /etc/rc.local |grep xmodmap
/usr/bin/xmodmap /home/delta/.Xmodmap

Here it’s my complete xorg.conf
I strongly recommend you to make a backup of your working xorg.conf before changing it.
To apply any changes you must restart the x-server (by pressing ctrl+alt+backspace).

6.1) SYNAPTICS TOUCHPAD FULL FUNCTIONALITY

We must add a InputDevice section in /etc/X11/xorg.conf like this:

Section "InputDevice"
    Identifier "Synaptics Touchpad"
    Driver "synaptics"
    Option "SendCoreEvents" "true"
    Option "Device" "/dev/psaux"
    Option "Protocol" "auto-dev"
    Option "HorizScrollDelta" "0"
EndSection

And also, inside “ServerLayout” section add this line:

InputDevice "Synaptics Touchpad"

6.2) 1280×800 RESOLUTION

Add “1280×800″ in the Modes lines on “Screen” Section. Like this:

Section "Screen"
    Identifier "Default Screen"
    Device "Tarjeta de video generica "
    Monitor "Generic Monitor"
    DefaultDepth 16
    SubSection "Display"
    Depth 8
    Modes "1280x800" "1024x768" "800x600" "640x480"
    EndSubSection
    SubSection "Display"
    Depth 16
    Modes "1280x800" "1024x768" "800x600" "640x480"
    EndSubSection
    SubSection "Display"
    Depth 24
    Modes "1280x800" "1024x768" "800x600" "640x480"
    EndSubSection
EndSection

6.3) DRI (Direct Rendering Interface)

At kernel level there must be the DRM_I915 (i915.ko) module

In /etc/X11/xorg.conf:

Section "Module"
    (...)
    Load "dri"
EndSection

Section "DRI"
    Mode  0666  #to allow all users access to DRI
EndSection

There are also necessary the libgl1-mesa-glx libgl1-mesa-dri libglu1-mesa packages.
As well we can install mesa-utils in order to check if DRI is working with glxgears demo, for example.

The module ipw2200 is already included on 2.6.25.9 kernel. (I don’t know for how long, but sure it wasn’t included on 2.6.22) Also is included the patch to get it into monitor mode (creating the rtap virtual device)

In order to load the module with the rtap interface enabled you can create the file /etc/modprobe.d/ipw2200 and write into it:

 options ipw2200 rtap_iface=1

If you want avoid some firmware errors you can try also adding:

 options ipw2200 hwcrypto=0

See also “Power Saving” section.

If you have a previous kernel maybe you must have to compile the module by hand. I explain in this other article (in Spanish, I’m sorry) how to do it with the monitor mode enabled.

To analyze the power consumption we can use the awesome ‘powertop’ Intel tool.
It gives some advices to save battery that we can add to rc.local (to load them on boot):

delta@sr50:~$ cat /etc/rc.local
#!/bin/sh -e
## Temperature polls each 2s
echo 3 > /proc/acpi/thermal_zone/THRM/polling_frequency
## Underclocking
cpufreq-set -u 1.33G
## Enable AC97 powersave mode
echo Y > /sys/module/snd_ac97_codec/parameters/power_save
## Increase the VM dirty writeback from 5s(default) to 15s
#echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
## Saving-power mode of wifi card (can take values form 1 to 5)
iwpriv eth2 set_power 5
## Disable CDROM pollings
hal-disable-polling --device /dev/hdb
exit 0

Note that I have commented the dirty_writeback one, because it could be unsafe when working only with AC adapter without battery, be aware of this.

I also recommend the use of laptop-mode-tools which allows you to configure some different power consumption parameters between AC and Battery modes.

You can manage the VGA, LVDS and TV displays with the X11 RandR extension (libxrandr2 package). See `man xrandr` for information.

You can download this script I’ve made to on/off an external VGA display alternating between three states: (LVDS)->(LVDS+VGA)->(VGA). Something like Windows XP does when you press Fn+F4
It assign the maximun possible resolution on VGA. You can make a keybind to launch it (Win+F4 for example).

PCMCIA – works fine. I have tested it with a SMC wifi-card.
WIRED LAN CARD (Broadcom BCM4401) – works perfect.
MODEM – Not tested yet
CARD READER – Not tested yet

11.1) FAN ALWAYS ON

Main hardware problem in my opinion: The fan is always on. It’s controlled directly by the BIOS and as long as I concern you can do nothing about it. Doing:

sr50:~# echo 3 > /proc/acpi/fan/FAN1/state
sr50:~# cat /proc/acpi/fan/FAN1/state
status:  off

But the fan will be already spinning. It’s not a serious problem appart from the “noise”.

11.2) FN-KEYS PICTOGRAMS

The pictograms shown on the top left corner of the screen when pressing some Fn-keys (Brightness, Etiquette-Mode, Battery, etc.) aren’t seen well.

There is a solution consisting on installing vbetool package and adding to the /etc/init.d/x11-common this line near the top:

vbetool post

This solution can be work well for you if you always use a Graphical environment and you load it automatically on boot, but it’s no good to work on native tty’s.

11.3) BUTTON LID

delta@sr50:~$ cat /proc/acpi/button/lid/LID0/state
state:      closed

Although it’s open

This kernel bug must leads you to deactivate possible actions linked with the closed state of the lid that some Desktop Environments like KDE or GNOME must have. For example, it’s possible that your laptop go into suspension mode just after loading KDE on start.

It’s not an important problem, of course, since you can link the suspension event to sleep or power button (see “Suspend” sections)

PROGRAMMING. JAL

To program the robot we will use JAL (Just Another Language), a totally free high-level programming language, including its free-software compiler, that can be used with some PIC microcontroller of Microchip(TM), like the 16F877 in Mark-III robot.

Writing programs

To write JAL programs we can use any text editor, like VIM or EMACS, nano, kwrite, gedit, etc.

Compiling JAL code

We will use the JAL compiler with The Gnar patch for Mark-III.

Downloads:
JAL compiler
Mark-III patch and examples

Installation:

(instructions on README file inside markiii_jal_0_4_64.tar.bz2)

To apply the patch

patch -p1 < ../jal_4_62_MIII.patch
./configure; make
(as root) make install

We can find several examples of JAL code for our robot inside the markiii_jal file: tests for sensors and to calibrate servos, even a sumo program.

JAL compiler needs gcc (GNU compiler collection), who is present by default in almost GNU/Linux distributions.

Using the compiler:

Is important to have in our library folder (/usr/local/share/jal/lib) the following files: 16f877_20.jal, jdelay.jal, jpic.jal, jrtl.jal, jsevenp.jal, markiii.jal, jascii.jal, jlib.jal, jprint.jal, jseven.jal, jstepper.jal.

Once we have our program.jal we can compile it as follows:

jal -s/usr/local/share/jal/lib program.jal

This will generate 2 files: one program.asm, the associate assembler code of our program and a program.hex, the executable one. This last one will be downloaded into the robot using Minicom and the Rick Farmer’s PICLoader, that is a monitor operating system for PIC16F87x who manages the communication of the robot by serial port and loads the user programs.

If our pic was unprogrammed, we would have to download the PICLoader v1.1 and use a programmer board.

COMMUNICATION BY SERIAL PORT. MINICOM

Having the PICLoader in our pic we will be able to communicate with the robot by serial port using Minicom, that accomplish the same function of Windows’ Hyperterminal, although being less “user-friendly”.

I have seen a multiplatform program called moni 2.20m3 for the communication with Mark-III in a graphical way, but I haven’t tested it yet, so I can’t guarantee its correct working.

Configuring Minicom:

[What I show here has been tested with 2.3-rc1 version]

We create a folder in our home called, for example, ~/tx where we will put the .hex to send to the robot.

We start Minicom in a terminal.
We can see the options by ‘C-a o’ (that is: press Ctrl+a and then o)
-> Filenames and paths:

    B - Upload directory  : /home/user/tx

-> File transfer and protocols: (ASCII line delay of 100ms)

    I  ascii      /usr/bin/ascii-xfr -dsvl 100    Y    U    N       Y       N

-> Serial port setup: (38400 baud, 8 bits, no parity, 1 stop bit, No flow control of any kind)

    A - Serial Device     : /dev/ttyUSB0

I’m using a USB-RS232 adapter (more info: article), so here we see ttyUSB0, but if you use your COM port directly, you must introduce ttyS0 or ttyS1 (COM1 o COM2).

    E - Bps/Par/Bits : 38400 8N1

    F - Hardware Flow Control : No

    G - Software Flow Control : No

Save setup as .minirc.dfl

Sending programs:

Once we have configured Minicom and our program.hex is in tx folder, we can connect the  robot, switched off, to our computer through the serial cable and we start Minicom.
After that we switch on the MarkIII and we must see something like:

8K PICLOADER v1.1
Copyright Rick Farmer 1999
Current image = follow
PIC>

We can press ‘?’ to see the options of the PICLoader. We choose ‘U’ to load our program:

PIC>U
Are you sure? [y/N]>y
Erasing
########################
Ready

Now we must select our program, for that we press ‘C-a y’, we navigate by the list, select with SPACE key and finish pressing ENTER. Minicom will send automatically our executable line by line to the PICLoader. We will see something like that:

########################################################################
Upload succesful
Enter a rev string>

Here we can enter a tag to our program, in order to identify it next time we connect the robot.

Enter a rev string>name
Current image = name
PIC>

To exit Minicom: C-a x

Few things about the communication with the robot:

* (Having a program loaded into the robot) At PICLoader’s start, it will wait 5s for serial port events and, if there’s no event, it will jump to user program. So, if you want to load another program, when countdown is shown:

PIC>###

press ENTER

* The robot programs can have instructions that send data to the computer by the serial port, like in the case of sensors and servos tests. Then, if we have Minicom connected, we will be able to see this data on the screen.

As laptop computers don’t have RS232 serial port we must buy an adapter USB-RS232_DE9. I have bought a Digitus© one for 17 Euros (a little bit expensive in my opinion).

For me, it has been also necessary to build a connection cable because my second-hand calculator haven’t had one.

We connect the adapter to an usb port of our laptop, and then if we made (as root):
# lsusb
we must see something like this:

Bus 003 Device 001: ID 0000:0000
Bus 005 Device 001: ID 0000:0000
Bus 004 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 010: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO
Bus 001 Device 005: ID 15ca:00c3
Bus 001 Device 001: ID 0000:0000

where Device 005 is my usb mouse and the 010 is our new usb-serial adapter.

With last Linux kernel versions (at least since kernel 2.6.18) the suitable driver (kernel module) is automatically loaded after plugging in the device, and it is also auto-unloaded at unplugging.

So, if you do:
$ dmesg | tail
you should see something like:

usb 1-1: new full speed USB device using uhci_hcd and address 10
usb 1-1: configuration #1 chosen from 1 choice
ftdi_sio 1-1:1.0: FTDI USB Serial Device converter detected
drivers/usb/serial/ftdi_sio.c: Detected FT232BM
usb 1-1: FTDI USB Serial Device converter now attached to ttyUSB0

That shows that udev has attached the device to /dev/ttyUSB0.

My module is ftdi_sio (Future Technology…). But if the adapter was, for example, a Conceptronic© one (Prolific Technology, Inc. PL2303 Serial Port), its module would be pl2303.

if the module is not autoloaded, you should load it manually:
# modprobe usbcore
# modprobe usbserial
# modprobe ftdi_sio

Until now we have only plugged in the adapter and checked that all is correctly loaded. Now is time to install a software to communicate with the calculator. For GNU/Linux we have HP Talx, that is a GTK+ graphical interface of C-Kermit.

As HP Talx depends on C-Kermit, first we have to install this package, present in repositories of several distributions. In Debian-like ones, we can do:
# aptitude install ckermit
Next we download the deb package of last version of HP Talx and we install it with:
# dpkg -i hptalx_version.deb
In the case of distributions without package system we can download the sources (ckermit, hptalx) and compile them with:
./configure; make
[as root] make install

We run HP Talx, we turn the calculator on and we press [gree key] and [I/O] (button 1), we select Transfer… and we configure the parameters like:

PORT: Wire
TYPE: Kermit
NAME: (none)
FMT: Bin
XLat: 255
CHK: 3
BAUD: 9600
PARITY: None
OVRW: (ticked)

We go out of the transfer configuration and we press [green key] and [right arrow] to begin the server. We must see “Awaiting Server Cmd” on the screen.
Now in HP Talx we configure the connection in File > Setup… (or CTRL+N)

Connection Settings: USB (ttyUSB)
Set ttyUSB port: 0
Set COM Speed: 9600
Timeout: 15
Confirm Delete and Remove: (ticked) *
Start Connected: (unticked) *
Set default editor: kate *

(*) As you like

Finally we connect: Connect > Connect (or CTRL+B)

If all has gone fine we must see something like:

Now we can upload our programs to the calculator, libraries, variables, texts… and of course, also download them from the calculator to our computer.
From hpcalc.org we can download houndreds of applications (technical, graphics, editors, games, etc.) for HP48 and HP49.

NOTE: For Windows we have HPComm that is free software and works very well.