J-Dii's Blog

App-a-Day 2: Singapore MRT

2011-07-20T17:33:00.001+02:00

"Singapore MRT"
OK, this was kinda cheap to delete. A useful map of the Singapore subway MRT service. But only useful in Singapore... ;-)
My rating: 4/5 stars.

App-a-Day 1: Singapore Travel Guide

2011-07-19T22:14:00.001+02:00

"Singapore"
I used this on a trip to Singapore this spring. Pretty useful for a quick overview of the most prominent sights of the country. Useful agenda function.
My rating: 4/5 stars.

New Project: An App a Day - UNINSTALLED

2011-07-19T21:51:00.001+02:00

I have been using Android since early 2010, first on a Samsung Galaxy Spica, now (since April) on a Nexus S. While the limited memory of my first phone forced me to strictly limit the number of apps I kept on my phone, I have been really wasteful since having about one gigabyte of space for apps (not counting the 15GB of internal storage for "App2SD").

Since April, I have accumulated well over 150 apps (166 right now, not counting the apps I uninstalled in the past days). Way to many, it seems.

Many of the installed apps I only tried once and never ran them again. Others are used rarely but worth keeping. However, there are even apps thatbI have not run at all. In order to reduce the number, I will be trying to uninstall an average of 1 app per day and report it here.

Pullup of Dallas/Maxim 1-Wire on AVR or Arduino

2010-08-11T07:59:00.005+02:00

Just a quick hack: You can avoid using the required 4k7 pullup resistor for the 1-wire data line by using an AVR pin in pullup mode (i.e. input mode, set to high). This has to be an extra pin, not the data pin itself (unless you are paying special attention in your 1-wire protocol routines). Also, it probably won't work for long wires or large 1-wire networks (I tried it using a single DS1820 temperature sensor very close to the AVR).

Python Script VCF Photo to Google Contacts

2010-02-26T17:18:00.006+01:00

Google Contacts does not yet import Photos embedded in VCF (VCard Files) during import from an existing addressbook. I wrote a little script that does that for you:
Contacts must already exist in Google (import VCF in Google first).

- Configure the script by adjusting the 4 variables at the top
- Contacts must already exist in Google (import VCF in Google first)
- Photos are cropped to 96x96 in the middle using ImageMagic (via command line) to match Googles image limit
- Contacts are matched based on the Full name (FN in VCF) / Entry Title (in Google)

Updates:
- Version 1.1: Fixed Unicode-Handling


#!/usr/bin/python
# -*- coding: utf-8 -*-

""" Script to upload photos from a VCF addressbook to Google Contacts
    Contacts must already exist in Google (import VCF in Google first).
    Photos are cropped to 96x96 in the middle using ImageMagic (via command line) to match Googles image limit
    Contacts are matched based on the Full name (FN in VCF) / Entry Title (in Google)
    Version: 1.1
"""

# Configuration:
vcf_filename = "addressbook-2009-11-10.vcf"     # VCF file to read
google_login = "mymail@gmail.com"               # Your google Email address
password = None                                 # if none -> prompt
max_results = 5000                              # use low number for testing


import vobject
import StringIO
import atom
import gdata.contacts
import gdata.contacts.service
import sys,os,time


# temporary files
image_filename = 'photo.jpg'
cropped_image_filename = "photoc.jpg"

f = open(vcf_filename)

gd_client = gdata.contacts.service.ContactsService()
gd_client.email = google_login
gd_client.password = None
gd_client.source = 'exampleCo-exampleApp-1'

if gd_client.password is None:
    import getpass
    gd_client.password = getpass.getpass("password:")

gd_client.ProgrammaticLogin()

query = gdata.contacts.service.ContactsQuery()    
query.max_results = max_results
#print "query:", query.max_results, query.ToUri()
feed = gd_client.GetContactsFeed(query.ToUri())

for v in vobject.readComponents( f ):
    #print v.contents
    if "photo" not in v.contents: continue        
    #v.prettyPrint()    
    name = unicode(v.fn.value)
    
    for i, entry in enumerate(feed.entry):
        if entry.title.text is None: continue
        title = unicode(entry.title.text, "utf-8")
        if title == name:
            print "Uploading Photo for", name.encode('utf-8'), "to", title.encode('utf-8')
            # Update foto!
            p = open(image_filename, 'w')
            p.write(v.photo.value)
            p.close()
            
            # Change size to 96x96
            cropped_image_filename = "photoc.jpg"
            cmd = "convert "+image_filename+" -gravity Center -crop 96x96+0+0 "+cropped_image_filename
            os.system(cmd)
            
            try:
                photo_metadata = gd_client.ChangePhoto(cropped_image_filename, entry, content_type='image/jpeg')
            except gdata.service.RequestError:
                print "Didn't work!"

Bookmarklet to the TU-BS Mensa

2009-10-27T13:39:00.005+01:00

To directly go to Todays menu, use this bookmarklet (drag it to your Bookmark Bar, works in Chrome, Firefox, ...):

Mensa

WPA Wifi with MSI Wind (RTL8187SE) on Ubuntu 9.04

2009-09-16T23:28:00.003+02:00

My MSI Wind used to have trouble keeping a WIFI connection going when I used WPA/WPA2. The connection was frequently lost, usually when large amounts of data were transferred (downloads). This could be fixed by reconnecting, but that really was a PITA.

This behavior happened with the rtl8187se driver that shipped with Ubuntu 9.04. Being desparate, I gave NDISWrapper a try, which is a generic driver that uses original Windows WiFi drivers. I basically just followed the Ubuntu guide at http://wiki.ubuntuusers.de/WLAN/NdisWrapper (German), using the windows drivers provided by MSI (http://global.msi.eu/index.php?func=driverfile&dno=6922&i=1).

After rebooting, I made sure that the ndiswrapper was used (i.e. checked that the rtl8781se driver was not loaded) and used the wicd tool to connect to my favourite WPA2-secured WLAN access point. Voila! The connection seems to be stable.

I am not aware of any drawbacks of using the ndiswrapper. It seems to run stable (especially compared to the "original" ubuntu driver). Maybe battery consumption is not as good?

Overview of Python Graph Packages

2009-04-28T09:35:00.008+02:00

I wanted to create a graph of a network with directed edges including edge labels from a simulation file. Since most of my scripts are written in python, I wanted to use a python-based approach. Most of them are based on Graphviz.

Also, I found that many of these packages are strongly overlapping. So maybe its reasonable to consolidate... BTW: I ended up using pygraphviz. Here are my findings:

pygraphviz

http://networkx.lanl.gov/pygraphviz/
Support for all sorts of attributes (in latest version - the one in ubuntu hardy has only little support)
Direct generation of graphs
Good documentation

python-graph

http://code.google.com/p/python-graph/
Supports all sorts of attributes (edgelabels etc.)
Requires manually calling of graphviz (dot, neato)?

pydot

http://code.google.com/p/pydot/
Seems similar to python-graph
Supports all sorts of attributes (edgelabels etc.)
No documentation
Requires manually calling of graphviz (dot, neato)?

NetworkX

http://networkx.lanl.gov/index.html
Seems to be related to pygraphviz
Good documentation
No support for edge labels
Directed edges look strange

graph-tool

http://projects.forked.de/graph-tool/
Haven't taken a closer look...

"Turbo Mode" for mobile browsing

2009-03-13T16:00:00.006+01:00

I just read about the turbo mode in Opera 10, which sends images through a proxy that compresses them to save bandwidth on the end user.

This sounds really useful for a mobile phone web browser like Minimo or Midori. But relying on a proxy to scale the images might not suit an opensource browser because of the infrastructure cost for the proxies. However, maybe Google Image could be (mis-)used as a proxy to at least scale down the images.

Another option is to use interlaced/progressive images, which is supported by most image formats for the same purpose. In "turbo mode", the browser would only load enough data to display a rough preview of the image, hence conserving bandwidth. The user might then selectively load the rest of the image later.

This of course requires the image to be encoded in interlaced format in the first place, which is not common. But it might become common when minimo/firefox/webkit implements such a turbo mode...

What do you think?

Controlling MSI Wind fan speed from Linux

2009-03-06T22:34:00.003+01:00

In search of a way to silence my MSI Wind (esp. when running Linux), I found this Thread and a coresponding tool for Windows/Dos: http://forums.msiwind.net/post85863.html

I created a port to Linux, which can be found on my sites.

Tracing with SystemC using gtkwave

2009-01-20T13:47:00.004+01:00

I have found few sources of information on this, so I'd like to share my experiences.

Most importantly, use the commandline switch -o when opening VCD files with gtkwave:

gtkwave -o MyTrace.vcd

This generates a hierarchy from hierarchical names like "TOP.module1.signal1".

Using rsync with FAT filesystem

2008-12-28T16:22:00.009+01:00

The VFAT filesystem, which is commonly used on USB-Sticks and MP3-Players, requires special options for use with rsync:

rsync -rvt --modify-window=1 [from] [to]

-rvt does a recursive sync, preserves the modification time (so a later rsync can recognize identical files) and is verbose.

--modify-window=1 avoids "false positives". It is required because VFAT only has a resolution of 2 seconds for the timestamp, while most other filesystem offer a resolution of 1 second.

Another useful option is -n, which performs a "dry run".

VCard to HTML Script

2008-12-09T19:57:00.006+01:00

I needed a way to display contacts (in VCF Format) exported from KDE's KAddressbook (the contact management in Kontact). I found this perl script that converts vcf to text, which I used as a starting point.

Features of my script (call it vcf2html or vcard2html) so far:

Reads a VCF containing multiple contacts
Generates a single HTML file to stdout
Supported fields: Full Name (FN), Organization (ORG), ROLE, EMAIL, ADDRESSES, Phone Numbers (TEL), URL, Birthday, Notes,
Photos are saved into the current directory

Usage:

vcf2html.pl addressbook.vcf > addressbook.html

The script looks like this (copy and paste into text editor and save as vcf2html.pl. Don't forget to make it executable):

#!/usr/bin/perl
# Copyright (C) 2008, Jonas Diemer
# Based on vcard-view.pl, Copyright (C) 2008, Steven Allen
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see .

# This program parses vCards and displays their contents in a
# human readable form.

# Import libtext-vcard-perl library
use Text::vCard::Addressbook;
use Text::vCard::Node;
use Text::vCard;
use utf8;
use HTML::Entities;

use MIME::Base64;

# Get card name
my $card_file = $ARGV[0];

# Create Addressbook
my $address_book = Text::vCard::Addressbook->new({
 'source_file' => $card_file,
});

#HTML header
print "<html>\n";
print "<head>\n";
print "  <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n";
print "  <title>VCF2HTML: ".$card_file."</title></head>\n";
print "<body>\n";

# $s = "Smöre Bröd > X\n";
# print $s;
# print encode_entities($s);

#Loop through Addressbook
foreach my $vcard ($address_book->vcards()) {
  print "<table><tr><td valign=top>\n";

  # PHOTO
  if ($vcard->photo()){
    open(file, ">".$vcard->uid().".jpg");
    print file decode_base64($vcard->photo());
    print "<img src=\"".$vcard->uid().".jpg\"/></br>";
  }
  print "</td><td valign=top>";
  print "<table>\n";

 # Name
 print "<tr class=Name>\n  <td>Name:</td>\n  <td>" . $vcard->fullname() . "</td>\n</tr>\n";

 # ORG
 my $orgs = $vcard->get({ 'node_type' => 'ORG' });
 foreach my $org (@{$orgs}) {
   print "<tr>\n  <td>Organization:</td>\n";
   $n = $org->name();
   $n =~ s/\\,/,/g;
   print "  <td>". $n ."</td>\n<tr>\n";
 }

 # ROLE
 if ($vcard->role()) {
  print "<tr>\n  <td>Role:</td>\n  <td>" . $vcard->role() . "</td>\n</tr>\n";
 }

 #email
 my $emails = $vcard->get({ 'node_type' => 'EMAIL' });
 foreach my $email (@{$emails}) {
   print "<tr>\n  <td>Email ".$email->types()->[0].":</td>\n";
   print "  <td>".encode_entities($email->value()) ."</td>\n<tr>\n";
 }

 # Address
 my $addresses = $vcard->get({ 'node_type' => 'addresses' });
 foreach my $address (@{$addresses}) {
   print "<tr>\n  <td valign=top>".$address->types()->[0]." Address:</td>\n  <td>";
   print "  " . encode_entities($address->street()) . "<br/>\n";
   print "  " . $address->post_code() . " ". $address->city();
   if ($address->region()) { print ", " . $address->region(); }
   if ($address->country()){
     print "</br>\n  " . $address->country();
   }
   print "  </td>\n</tr>\n";
 }

 # Phones
 my $tels = $vcard->get({ 'node_type' => 'tel' });
 foreach my $tel (@{$tels}) {
   print "<tr>\n  <td>".$tel->types()->[0]." Phone:</td>\n  <td>". $tel->value()."</td>\n</tr>\n";
 }

 # URL
 my $urls = $vcard->get({ 'node_type' => 'URL' });
 foreach my $url (@{$urls}) {
  print "<tr>\n  <td>Web:</td>\n  <td>" . $url->value() . "</td>\n</tr>\n";
 }

 # BDAY
 if ($vcard->birthday()) {
  print "<tr>\n  <td>Birthday:</td>\n  <td>" . $vcard->birthday() . "</td>\n</tr>\n";
 }

 # Notes
 my $notes = $vcard->get({ 'node_type' => 'NOTE' });
 foreach my $note (@{$notes}) {
  $n = $note->value();
  $n =~ s/\\n/<br\/>/g;
  $n =~ s/\\,/,/g;
  print "<tr>\n  <td valign=top>Note:</td>\n  <td>" . $n . "</td>\n</tr>\n";
 }

 print "</table><!--inner table->\n";
 print "</td></tr>";
 print "</table><hr>\n\n";
}

print "</body></html>\n\n";

MICRO-41 in Como, Italy

2008-11-15T17:10:00.005+01:00

I attended a very interesting conference (IEEE MICRO-41) in Como, Italy. Pictures are here.

Hello Blogging World

2008-11-09T17:51:00.002+01:00

This is my hello-world of blogs. The first step. First experiments. Nothing more, nor less. I don't know (yet) whether I will be doing any serious blogging, so lets just wait and see :-)