Saturday, May 30, 2009

how to set a serial port at MIDI speed in linux

Linux serial ports only work at standard speeds by default. MIDI runs at 31250 baud, which is not a standard speed. However there are tricks to get custom speeds, but documentation is quite fuzzy. This is a simple recipe that worked for me with an FT232 USB-Serial board.

Check the baud base of the device:

$ setserial -g -a /dev/ttyUSB0
/dev/ttyUSB0, Line 0, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 24000000, close_delay: 0, divisor: 0
        closing_wait: infinite
        Flags: spd_normal low_latency

As you can see the baud base is 24000000 here.
Next calculate the divisor by dividing the baud_base you see here by the speed you want.
In my case 24000000/31250=768.

Apply the new setting:

$ setserial -v /dev/ttyUSB0 spd_cust divisor 768

Next start your serial application, you might want to make sure it is already set to the correct speed before you do the above changes else it might destroy your settings. The correct speed is 38400 baud, which is now aliased to 31250.

With minicom just use the menu (CTRL-A Z) to change the settings.

Screen can be used like this:

screen /dev/ttyUSB0 38400

Exit screen by pressing CTRL-A CTRL-\


Tuesday, April 28, 2009

usb tiny isp programmer / user accessible

To make an usbtiny programmer usable directly as user from avrdude or the arduino toolkit, add the following line to a new file in /etc/udev/ :

ATTRS{idVendor}=="1781", ATTRS{idProduct}=="0c9f", MODE="0664", GROUP="plugdev"
I created a file called /etc/udev/joost.rules with this line.
Reload udev with /etc/init.d/udev reload

arduino toolkit on x86_64 linux Debian/Ubuntu


I received an email from Ethan Bisset with a much nicer solution: just use the debian provided serial library instead of the one provided with the arduino software.

This is his recipe:

1. Get arduino software
2. apt-get install sun-java6-bin binutils-avr avr-libc gcc-avr librxtx-java
3. Untar arduino software
4. Delete <arduino>/lib/
5. Done!

(below is the old entry:)

Download the linux 32-bit arduino toolkit from the arduino toolkit download page and untar in a directory.

Install the avr tools: apt-get install avr-libc binutils-avr gcc-avr

Install "ia32-sun-java5-bin". ( apt-get install ia32-sun-java5-bin )

Adapt the "arduino" startup script script and replace java in it by


Execute the "arduino" startup script. It works just fine now.

Thats all.

Many thanks to the Debian java packagers for providing this 32-bit compatibity jvm!

Friday, April 3, 2009

De Post - volmachten

Blijkbaar heeft De Post een nieuwe melkkoe gevonden: de kleine zelfstandige.

Vandaag stond de postbode aan mijn deur met aan pakketje voor de firma. Hij vertelde me doodleuk dat het niet mag afgeven worden, want ik moet hiervoor een volmacht hebben.
Deze volmacht kun je gaan halen op de post en kost elk jaar geld.

De postbode gaf zelf toe dat dit puur geldklopperij is.

Je bent dus gewaarschuwd: zorg dat verzendingen met de post als geadresseerde je privé gegevens bevatten en niet je firmanaam. Of werk met een andere firma dan De Post.

Ikzelf hang er nu al aan voor dit jaar.

Gelukkig is het zalig weer :)

Sunday, March 1, 2009

glibc 2.9 - maradns

As Debian has been released my "unstable" box recently upgraded to glibc 2.9.
This caused DNS resolving to mysteriously fail in some applications.

Turns out that only IPv6 enabled applications suffer.

Apparently libc now fires both an IPv4 and IPv6 DNS resolving request in parallel. It looks like some DNS servers don't handle that correctly and answer an error on the IPv6 request before the IPv4 request even has time to resolve further in the internet.

In my case it was my local NSLU2 running Debian lenny causing the trouble, more specific the maradns local DNS server and DNS proxy running on it.

I manually upgraded maradns to the latest version (> 1.3.10) and things are "back" to normal.

Another solution is to disable IPv6 systemwide but I prefer not to do that as I use IPv6 occationally for testing.

I fear that this will cause more trouble for alot of people with routers doing DNS proxying.

Sunday, February 15, 2009

Grote Nete

(click on the image to enlarge)

nikon d300 • tamron 17-50 f/2.8 • © 2009 Joost Yervante Damad


Saturday, February 7, 2009

openMSX 0.7.0

A new version of openMSX has been released!

Important new feature is save-states. This gave me the means to finally finish the very first game I bought as a kid: Konami's Nemesis 2 for the MSX computer.

In these times games were usually hard. Nemesis 2 is even harder.  The only way to play it without save-states is not dying all 15 levels. Given that Nemesis 2 is a shooter this is VERY hard :)


Each one of those red bullets and grey stones is fatal :)

But save-states wasn't enough. I also enabled "old-people" mode, meaning running the emulator at 75% speed of the original MSX computer.

After more then an hour of hard labour playing using alot of save-states I finally managed to finish the game.

Only 22 years late ;-)

P.S.: I checked with my MSX friends and no-one was able to finish this game without some form of cheating....

dell precision m6400 power brick

I'm really happy with my new Dell precision M6400.
The only thing most people complain about is the size of the power brick, and I can't agree more. It's a huge 200 Watt thing and it's really as large and heavy as a stone brick.

Luckily I still have a spare power brick of my old Dell precision M65: a 90 Watt  PA-10 family power brick. It has exactly the same voltage (19.5 Volt) so I decided to try it.
I've been using it now for a few days when at customer sites and it works fine.

(Try at your own risk!)

Thursday, February 5, 2009

icy little

(click on the image to enlarge)

nikon d300 • 70-300 vr • © 2008 Joost Yervante Damad



(click on the image to enlarge)

nikon d300 • sigma 300 f/4 • © 2008 Joost Yervante Damad


Monday, January 19, 2009

a month

Last year I even did it for longer then a month, but this year I want at least to redo a minimal effort, thus I'm going for a month of sobriety, as a kind of cleansing :) (and no, I'm not religious).

These are my 5 daily checkpoints:

  1.  smoothie for breakfast

    This is something which we (me and my wife) do already anyway, have a fresh fruit smoothie for breakfast. Currently our favorite mix is 4 blood oranges, freshly pealed and parted, a seep of  Sea-buckthorn elixir, and a couple of frozen strawberries (or cranberries). Mix all in the blender, long enough to don't have any parts left. It is extremely tasty, and gives a serious vitamin boost for the winter. The idea is to have it for breakfast and then don't drink or eat anything else for at least 1.5 hours, to make sure it's (almost) fully digested.

  2. < 4 coffee

    This is a hard one; people who know me will know I'm a serious coffee lover. I have a special espresso machine, and typically serve single origin or special blend coffees. It's hard to resist :)

  3. exercise

    Just a walk with the dogs already counts.

  4. no sugar

    This is usually not so hard for me, as I'm not into sweets anyway.

  5. no alcohol

    This is tougher. I'll have to stick to coffee, tea and fruit juices.
This is all as much a physical as a mental exercice :)

Wednesday, January 14, 2009


(click on the image to enlarge)

nikon d300 • tamron 17-50 f/2.8 • © 2008 Joost Yervante Damad


Tuesday, January 6, 2009

ducks taking off

(click on the image to enlarge)

nikon d300 • tamron 17-50 f/2.8 • © 2008 Joost Yervante Damad