Category Archives: Technology

Posts that relate to technology. Reviews, HOWTO’s, problems & solutions.

Discovery Error 4001 : Silicon Dust HDHomeRun error

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SiliconDust HDHomeRun Discovery error 4001I was in the process of changing out my MythTV backend machine, and when configuring the new machine, I took a look on SiliconDust’s website for a firmware update for my HDHomeRun (HDTV Network tuner box). I hadn’t updated it since late 2008, and sure enough, they were five or six firmware versions farther along. (Up to 20091024 to be specific.) So I upgraded the box using the newest version of the hdhomerun command line utility under linux. Everything went fine until the HDHomeRun rebooted. After that point, the utility said that an error occurred discovering the HDHomeRun! I tried booting into windows to try out the windows software, but it also could not discover the device, and gave me this ominous message:

Discovery Error 4001: Please email support@silicondust.com
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Learning Python for programmers – video lectures

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In my day job I teach students how to program. Recently, I gave three days of review lectures for my CS 1301 (Introduction to Computation – With Python and Robots) class. These three 50 minute lectures brushed over all of the major topics we covered in class very quickly. They would be very useful to somebody who knows how to program another language (such as Java or C), and wants to learn the basics of python in 2 and a half hours.

If you would like to watch more in-depth video lectures on any of the above topics, find the appropriate day in the class calendar and watch that video.

Running Ventrilo under Wine in Ubuntu Linux

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Wine will install and run the ventrilo VOIP client very well. To get this working, follow these steps:

apt-get install wine wine-dev msttcorefonts

download ventrilo-3.0.5-Windows-i386.exe

run “wincfg” to prepare things

run “wine ventrilo-3.0.5-Windows-i386.exe”
(go through the install, using all the defaults)

Now, everything works with one quirk.
Push to talk works only when the ventrilo window “has focus”
This is somewhat understandable, but annoying, in that you have
to focus the ventrilo window before you can talk.
The other option is to use voice-detection, but that takes up a bit more cpu-time, and you may accidentally broadcast something you don’t want to.

A program that listens for keypreses and directs them to the ventrilo window fixes this problem:

http://np1.pp.fi/ventriloctrl/
http://np1.pp.fi/ventriloctrl/ventriloctrl-0.3.tar.gz

To compile it, you’ll need xorg headers:
sudo apt-get install xorg-dev

Aiptek HyperPen T-6000U tablet with Ubuntu 9.04

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Getting the Aiptek T-6000U tablet working with Ubuntu 9.04 was relatively easy, following the directions here.

Summary:
Install the xserver-xorg-input-aiptek package.
Add a file called 10-aiptek.fdi to the /etc/hal/fdi/policy directory containing:

<?xml version="1.0" encoding="UTF-8"?> 
<deviceinfo version="0.2">
  <device>
    <match key="info.product" contains="Aiptek">

      <merge key="input.x11_driver" type="string">aiptek</merge>
      <merge key="input.x11_options.SendCoreEvents" type="string">true </merge>
      <merge key="input.x11_options.USB" type="string">On</merge>
      <merge key="input.x11_options.Type" type="string">stylus</merge>

      <merge key="input.x11_options.Mode" type="string">absolute</merge>
    </match>
  </device>
</deviceinfo>

Ubuntu 8.04 SSH login slow

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SSH Login to my Ubuntu 8.04 machine was slow. (It would delay about 5 seconds after I issued the ssh command for the remote machine to request a password.) I believe this is because the remote machine is on my home network, and I have set up it’s hostname using host entries instead of having a true DNS name.
I edited the /etc/init.d/sshd_config file and added the single line:
UseDNS no
which fixed this problem as soon as I restarted the SSH server, with
sudo /etc/init.d/ssh restart

Acer Aspire One D150 – Ubuntu 9.04 Jaunty Linux

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Installing Ubuntu 9.04 (Jaunty) on an Acer Aspire One (Model D150) worked quite well. I had to use an external USB CD-Rom Drive as the Aspire One does not have a built in drive, but after enabling the “Press F12 to choose boot device” menu in the system BIOS I was able to boot off of the external USB CD-Rom drive.
Ubuntu worked well with all the major hardware (video, wifi,wired-ethernet, soundcard, and webcam) and the only hiccup was with the built in microphone, which did not work out of the box (the microphone jack would work, just not the built in microphone.)

To get the built in microphone working, I had to install the latest version of the ALSA driver following the instructions I found in post 28 on this thread, as copied below:

So I downloaded alsa-driver-1.0.20.tar.bz2 from

http://www.alsa-project.org/main/index.php/Main_Page

I unzipped the package, I entered into the main directory of the package and then I typed:

sudo apt-get install build-essential ncurses-dev
./configure –with-cards=hda-intel
make
sudo make install

Then I edited /etc/modprobe.d/alsa-base.conf and I added at the end of file the line:
options snd-hda-intel model=acer-aspire

After the reboot I adjusted the audio preferences in this way:

Device: HDA Intel (Alsa mixer)
Preferences: The first 3 items and last 2 items (Front Mic is disabled!!!)
Input Sources is set as default at Mic (not Front Mic!!!).

Finally check that System->Preferences->Sound->Sound Capture is set to “HDA Intel ALC272 Analog(ALSA)” not “ALSA”

Electric Bicycle power circuit

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Bolting a DC motor to the front basket of a bike and running a chain to the front wheel takes care of the mechanical linkage needed to make an electric powered bicycle, but you also need to provide power to the motor, and control that power in some way.
Luckily, the same place that sold me the 250 watt motor also sold a 40 amp speed controler. (It cost $33, or more than any single other part of my e-bike project.)
40A motor controller

The speed controler is controlled by most standard e-bike throttles, such as this one from Currie Technologies. I also attached two 12v 5AH batteries in series to provide 24 volts. Because I calculated that my 250 watt motor running at 24 volts would draw approximately 10 amps, (250/24 = 10.4), I added a 15 amp fuse to the circuit. (The first 15A fuse was replaced by a second 15 amp fuse after it saved my speed controler from damage when I accidentally reversed the polarity on the power…)
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