Tomi Engdahl's ePanorama blog» Uncategorized

ePanorama.net is now in twitter

tomi — Thu, 18 Mar 2010 13:17:29 +0000

ePanorama.net has now a Twitter account so you can how follow the news related to this blog and ePanorama.net site in general. Twitter user name you should follow is epanoramanet.

Measure speed of light with chocolate

tomi — Fri, 19 Feb 2010 11:07:33 +0000

Wired magazine have an answer what to do with all of those leftover Valentine’s Day chocolates (if you have any). A microwave and some chocolate can be used to measure the speed of light. It is a simple yet surprisingly accurate method that can be used to introduce the scientific method to children. The details can be found at Leftover Valentine’s Chocolate? Use It to Measure the Speed of Light article. You get the 2450MHz microwave wavelength from the melted chocolate hot spots.

Tour of the International Space Station

tomi — Thu, 11 Feb 2010 07:03:32 +0000

An HD Video Tour of the International Space Station is simple walkthrough of this incredible project and all its corners. This video tour of the International Space Station is an interesting video, but is has also some annoying things on it. It sometimes overuses picture in picture and superimposed images effects in the video. Just because something can be done with a video, doesn’t mean it should be done.

My FAQs have new home here

tomi — Thu, 28 Jan 2010 21:14:06 +0000

I have maintained three FAQ lists for many years. Those FAQs are VGA to workstation monitor FAQ, sfnet.harrastus.audio+video usein kysytyt kysymykset (FAQ) and sfnet.harrastus.elektroniikka usein kysytyt kysymykset.

VGA to workstation monitor FAQ tells how to interface different RGB monitors to to PC VGA output and a little bit about connecting other RGB signal sources than PC to VGA monitors.

sfnet.harrastus.audio+video usein kysytyt kysymykset (FAQ) and sfnet.harrastus.elektroniikka usein kysytyt kysymykset are the official FAQs for two Finnish sfnet newsgroups. Those two FAQs are written in Finnish.

I started FAQs started sometimes in the 1990’s when I was a student at Helsinki University of Technology, nowadays from the beginning of 2010 known as Aalto University School of Science and Technology. The University web server has hosted those FAQs for all those years, even after I got my degree. Nowadays due the changes the old web system they got is retiring, so I the FAQs needed a new home.

Being the webmaster at a ePanorama.net I decided that this web site is a good new home for those FAQs. Moving the FAQs to here was easy, but making sure everybody will find the new location can be a task before the old address stops working.

I have already submitted the new URL to Google and added redirects to old address (let’s hope they will stay there active for a long time). I also need to inform the sfnet usenet newsgroup maintainers of the new web address so it gets posted to newsgroups instead of the old one. And then there are many other search engined to to take care. So what are the the best tools nowadays to add/update the URLs on the major search engines easily? I would prefer free on-line tools to do that.

Academia vs. Business

tomi — Thu, 19 Nov 2009 07:03:47 +0000

xkcd webcomic has today a funny comic about difference between academia research and business. Check out that Academia vs. Business strip yourself on the comic web page (the comic strip picture is too big to fit to the layout of this blog so I could not add it nicely here).

What If They Turned Off the Internet?

tomi — Mon, 26 Oct 2009 08:55:22 +0000

What would happen if they’ve turned off the Internet. After the riots have settled down and the withdrawal symptoms have faded, how would you cope? Cracked.com asked you to Photoshop what life would be like in an Internet-addicted society learning to cope without it. The World of Tomorrow (If The Internet Disappeared Today) picture collection shows you the best 20 pictures.

Your TV could be watching you

tomi — Wed, 12 Aug 2009 14:09:33 +0000

Twice a year, tech companies descend on CableLabs’ Innovation Showcase to demo their wares for a group of cable operators. PrimeSense’s 3D sensing chip won the ops’ vote in an informal poll for best new product idea. This product lets digital devices see a 3-D view of the world. The device includes a sensor, which sees a user (including their complete surroundings), and a digital component, or “brain” which learns and understands user movement within those surroundings.
This system provides something similar to thermal images, showing how many people are in front of the TV. Do we really need cable and/or video service operators knowing this? This system can also track and react to user movements outside the computer.

Live 2011 Grand Prix

tomi — Tue, 11 Aug 2009 12:19:01 +0000

Turku (a city in Finland) will be the European Capital of Culture for year 2011. For this reason Turku has initiated the world’s largest media art and new media competition Live2011 Grand Prix. They were making co-operation with the Assembly Summer 2009 festival where I saw their booth. A digital capital of culture, Live2011.com will be opened in 2010.

Assembly Summer 2009 Festival

tomi — Tue, 04 Aug 2009 08:45:42 +0000

Assembly Summer 2009 is Finland’s largest computer festival. It takes place in Helsinki 6th to 9th of August 2009. ASSEMBLY is a four day computer festival, in which thousands of people and their computers spend the long weekend by meeting friends, playing games, surfing on the net, talking on IRC and enjoying the great productions from the demoscene. It is a great atmosphere of being with likeminded people. I have participated many times this festival when I was younger. ASSEMBLY events are organized by ASSEMBLY Organizing, a group of over 200 volunteers backed by a not-for-profit Finnish company. I have been part of ASSEMBLY Organizing many years working for AssemblyTV TV production done at the festival. Designing and building all the technology needed to run a long live TV broadcast and the audio/video systems for the event itself has been a very good experience. I have learned a lot how big shows are built. It takes a lot of audio, video and computer technology to make this kind of event. The audio/video noise problems I have faced at Assembly and other events have been working with inspired to write my Ground loop problems and how to get rid of them document.

Floating measurements

tomi — Fri, 31 Jul 2009 09:54:14 +0000

A floating measurement reads the voltage between two points, neither of which is at ground potential. A most typical floating measurement done quite often is when doing voltage measurements with a battery powered multimeter. The floating insulated multimeter allows doing floating measurements of slowly changing signals easily.

The advent of switching power supplies and motor controllers brought a need to characterize waveshapes, timing, distortion, and other dynamics. Today’s power measurements call for an oscilloscope. Floating measurements of fast AC signals are a challenge for conventional instruments. The traditional line-powered benchtop oscilloscope models typically lack the possibility of making floating measurements. There are many compact battery-powered scopes around, but many of them have inadequate bandwidth and sample rate for accurate high-frequency waveform capture. Floating measurements have unique requirements over and above the usual considerations of bandwidth and resolution. Foremost among these issues is operator safety.

The Three Facets of “Floating” Measurement Solutions document at Tektronix web site examines the available alternatives for measuring AC signals in an ungrounded environment. It will show how the balance between three characteristics safety, packaging, and performance determine an instrument’s effectiveness for making floating measurements.