March 18th, 2010
Broadband through LEDs tips up article tells that German Scientists believe the light coming in to your home could by encoded to receive a wireless broadband signal. The scientists think they can transport data at high bandwidths (currently 230Mbps) by generating a signal in a room by slightly flickering all the lights in unison. The theory is that lights will have to be LEDs to flicker quickly enough and only use the blue part of the LED spectrum to filter out noise. The only “new” idea here is replacing the last couple of meters of bidirectional cat5 delivery with a unidirectional flickering LED, the rest of the way the data would need to go through traditional ways, most probably using some data over mains technology to special LED light bulbs.
This does not sound very new idea. Free space optical broadband has been proposed many times before. It has been coming and going. The technology world is makes circles. Oldest application of optical free space communications has probably been flashing lamp with Morse code. Then there has been TV remote controllers, IrDA some wireless LAN ideas with optical components and various point to point free space optical communications ideas (I have seen demonstrations). Nothing very new in this idea. If you want to play with optical communications ideas more here are some pages worth to look: ePanorama.net optoelectronics, my serial data IR transmitter and receiver circuit and my experimental laser data link.
Posted in Electronics Design, Telecom and Networking | No Comments »
March 16th, 2010
THX began life as part of LucasFilm. The initial goals for THX was to ensure that movie audiences in theaters heard the same audio that sound engineers heard in the listening booth after the final audio mix. Eventually, that goal has mutated.
The new THX idea was to ensure that home theater buffs heard the same quality and levels of audio as those sound engineers. Most people now about THX through logos on certified hardware. The implication of buying THX certified gear is that you get that sound mixing room environment. Any home theater enthusiast will know this simply isn’t the case. Simply buying THX certified equipment does not guarantee good sound, there are many other much much more important things that need to be right than the certification on equipment (for example room acoustics). THX certification brings to the table hardware that meets a consistent, minimum set of standards. To get good sound you need to use them in the right way and have good room acoustics.
According to AnandTech article THX Certified HDTVs – Useful or Just Marketing? the THX goal has mutated again. The article tells how the THX certification business works and what it means for TVs. THX tries to define a listening (or, in the case of HDTVs, viewing) experience, rather than just a set of hardware specs. The very act of doing that makes the company somewhat controversial. Since the logo program is a major part of THX’s revenue stream, obvious potential conflicts can occur. What does it mean when THX certifies an HDTV and does it matter anyway? What does the THX mode in an certified HDTV do? Read the article and make your own conclusions. The implications of a THX logo are perhaps stronger than the actual end result.
Posted in Audio and Video, Products | 3 Comments »
March 15th, 2010
Shanzhai ji gallery: Fake phones from China article looks into a Shanghai tech market to sort the fake from the real and to see how the fake iPhones stack up to the real thing. There are many brands of China Mobile Phones and almost of them are fake mobile phones with cheap price. This is an interesting gallery that includes also fake Nokia phones. According to news the market share of Nokia has dropped because of large number of fake Nokia phones on the market for example in China.
Posted in Mobile, Telecom and Networking | 3 Comments »
March 14th, 2010
The main selling points of Java is that it can actually be used on any computer. All that the computer needs is an interpreter for Java bytecode. Such an interpreter simulates the Java virtual machine in the same way that Virtual PC simulates a PC computer. Theoretically if you write a Java program well, it should work on any computer, and for many years to come.
In practice there have been too many times where a certain Java program cannot be used on the computer you want to use it, even the computer has Java support in it. I have seen too many cases where a device configuration tool or user interface written with Java has become unuseable very soon, and you just can’t use that on modern computers. A typical case is that Java application has run nicely on some old Java version, but refuses to run on some newer Java version. And when you have a newer PC, you can’t get the needed very old Java version to that PC in any practical way. And the manyfacturer does not provide any updated softwere. So the somewhat old still well working hardware or software system too soon becomes unuseable, because the Java based user interface just don’t work.
Java is supposed to run on any PC, but in practice many Java application just don’t work. Why does many Windows program seem take better time (even very old version runs nicely on modern Windows version or Windows emulator on Linux system)? Is the problem that Java keeps changing too much too often (problem to compatibility) or are the Java applications just so baddly written (in incompatible way)?
Posted in Computers | 2 Comments »
March 11th, 2010
I visited Microsoft Tech Days 2010 two days ago (I got free ticket), and if you are interested in technical stuff I leaned at the event and understand Finnish, you can my news report of that event published at Prosessori web site. I saw a quite interesting musical performance on the evening party. There was a band whose main instrument was two theremins (sorry for poor picture quality, this picure was taken on with cellular phone camera on and the lighting conditions were hard for taking photograps). The name of the band was Farther-Out (they said they have made some previous concerts and released one CD “Tuo”).
The theremin is an early electronic musical instrument controlled without contact from the player. It is named after its Russian inventor, Professor Léon Theremin, who patented the device in 1928. Theremins are distinguished by the fact that they are played without the performer touching the instrument. The musician moves his or her hands in proximity to the theremin to control the tone of the sound. I was told that mastering the theremin requires skills and lots of practicing, but only a few instrument provide the unique visual appearance of performance. The sound is quite unique for that instrument. Even if you don’t know theremin by name, you might have heard the sound of it at The beach boys -good vibrations or on the sound offects of some old scifi/horror movies.
The electronics of the theremin consists of two high frequency oscillators connected to antennas. When the player moves hand near the antenna, that changes the frequency of the oscillators, and that changes the sound (frequency or amplitude depending on antenna). Here is a block diagram of theremin from www.thereminworld.com Fred Tells All article.
All DIY persons now interested in theremin instruments can also view Make a Theremin video and check ePanorama.net theremin links.
Posted in Audio and Video, Electronics Design, Entertainment Technology, diy | 2 Comments »
March 10th, 2010
Nothing is perfect. The most common digital security technique used to protect both media copyright and Internet communications has a major weakness. RSA authentication is a popular encryption method. he RSA algorithm gives security under the assumption that as long as the private key is private, you can’t break in unless you guess it. Researchers find weakness in common digital security system tells that University of Michigan computer scientists have found they could foil the security system by varying the voltage supply to the holder of the “private key”.
They carefully manipulated the operating voltage of the computer electronics (FPGA). This causes it to make small mistakes in its communications with other clients (if it would make big mistakes it would crash). These faults reveal small pieces of the private key, and enough faults allows the researchers reconstruct the key offline. It takes considerable amount of time (100 hours) and many servers (
For more details read the whole FaultBased Attack of RSA Authentication paper. It describes an end-to-end attack to a RSA authentication scheme on a complete FPGA-based SPARC computer system and demonstrates that a fault-based attack on the RSA algorithm is possible.
It is highly unlikely that a hacker could use this approach on a large institution, so the risk of this to you could be pretty low. The researches say that a common cryptographic technique called “salting” that changes the order of the digits in a random way every time the key is requested, can help to fix this problem. There could also be other solutions as well (maybe better hardware more immune to error).
Image source: http://www.eecs.umich.edu/~valeria/research/publications/DATE10RSA.pdf
Posted in Computers, Electronics Design, Telecom and Networking | 2 Comments »
March 7th, 2010
Current design methodologies, whether for software or hardware, are in constant pursuit of making applications faster. In the office PC environment there is more than enough power for typical business applications, and they can be written using tools that are not the most optimized for execution speed (for example Java, .NET, scripting languages, web application etc..). Usually accerelaring the application in modern PC enviroment consist typically of things like multithreading, parallel processing, or reconfiguration.
Embedded systems are a different story. In many SOC (system-on-chip) applications, signal processing consumes the majority of the execution time. Using normal mathematical libraries for processing data is expensive in terms of both CPU time and memory usage. Acceleration of program execution article gives you information how to speed up the program execution beyond what you get with normal libraries. The article is written from an electrical engineer’s POV (point of view) and focus on the implementation in a given processor and the tradeoffs in implementation methodologies.
One popular technology to speed up the mathematics is to use look-up tables. Lookup tables trade between processing resources and execution time to speed up execution of computational processing. There is always tradeoff between execution time versus design time, and accuracy verses memory usage. Acceleration of program execution contains useful discussion and practical case studies that show that the lookup table method does accelerate program-execution speed considerably. In embedded applications the accelaration of program execution usully means that you can use a cheaper microprocessor and/or use less power than what would be the case with non-optimized program.
Posted in Computers, Electronics Design | 2 Comments »
March 5th, 2010
Google says desktop PC is three years from ‘irrelevance’. Google Europe boss John Herlihy told a “baffled” conference audience that very soon the smartphone will completely eclipse the desktop. “In three years time, desktops will be irrelevant,” he said. “In Japan, most research is done today on smart phones, not PCs.” Herlihy was trying to say that Google’s number one concern is now the mobile market.
For companies the number one concern is now the mobile market because mobile makes the world’s information universally accessible. This will create new opportunities for new entrepreneurs to create new business models – ubiquity first, revenue later. This is an interesting market.
PC will not be not irrelevant any time soon. At last month’s Mobile World Conference in Barcelona Eric Schmidt did not say that the desktop PC would be irrelevant in three years. The PC market might not be increasing at great rate, but is is not declining. I would expect that the PC will (in for or another) continue to be well for a long time. There has been many cases where PC has been said to be deaf because of different new things, and for some reason PC technology has survived almost 30 years on the market. PC will not go anytime soon. PC will be relevant for long time. PC will adapt over the time to form that is needed. PC is a flexible product that will live for long time.
Posted in Computers, Telecom and Networking | 2 Comments »
March 4th, 2010
Moore’s Law observes that the number of transistors doubles for the same area every two years. Strange that this law has hold for a long time. This has made some people to predict that that 32-bit processors will replace 8-bit processors. The argument starts with the fact that the relative size difference between an 8- and a 32-bit-processor core approaches zero compared with the other resources on the chip as the transistor geometry continues to shrink. When the difference in the silicon area of 8- and 32-bit cores shrinks to nothing, 8-bit processors lose the price advantage that they once enjoyed.
How low can 32 bits processors go? article tells you this and the fact, but also that this is not the whole story. 8-bit controller have their advantages still in applications where their processing power is enough. It is true that 32-bit cores are pushing everywhere (more capabilities and easier to program), but there are still applications where there is good place for 8-bit processors.
Posted in Computers, Electronics Design | 3 Comments »
