HackerThings web site is a list of products programmers and hardware hackers would want to own. HackerThings tries to aggregate the coolest products for the extremely tech-minded individual and discerning hacker. Products are posted to HackerThings on a purely is-this-awesome basis. Updates are posted daily. This is an interesting service to follow.
Eureka! Ditching DRM Decreases Piracy article tells that new paper to be published in the upcoming issue of Marketing Science shows that removing DRM from music leads to a decrease in piracy. Or phrased differently, DRM appears to be an incentive for people to pirate music instead of buying it. The researchers from Rice and Duke University used analytical modelling to come to this seemingly common sense conclusion. They conclude that DRM doesn’t prevent piracy at all. Quite the opposite what music companies expected. “DRMs haven’t worked, and may never work, to halt music piracy,” Steve Jobs said back in 2007.
“In many cases, DRM restrictions prevent legal users from doing something as normal as making backup copies of their music. Because of these inconveniences, some consumers choose to pirate,” DinahVernik, assistant professor of marketing at Rice’s Jones Graduate School of Business says.
DRM does not seem to work on games either. DRM Drives Gamers To Piracy, Says Good Old Games article says that it can actually drive gamers to piracy, rather than acting as a deterrent. In an interview, a spokesperson for Good Old Games said that the effectiveness of DRM as a piracy-deterrent was ‘None, or close to none.’ ‘What I will say isn’t popular in the gaming industry,’ says Kukawski, ‘but in my opinion DRM drives people to pirate games rather than prevent them from doing that. Would you rather spend $50 on a game that requires installing malware on your system, or to stay online all the time and crashes every time the connection goes down, or would you rather download a cracked version without all that hassle?”. According to Kukawski, the situation with restrictive DRM has reached the point where gamers often feel pushed into buying a game at full price, but then still download a cracked version to avoid the DRM.
DRM interrupts the user experience. Since when did any DRM solve piracy? I’d love to hear some high-level exec answer the question of “Why use DRM if it doesn’t stop piracy?”. The problem is that pirates don’t care about copy protection, it does not stop them. DRM doesn’t do a damned bit of difference to piracy – the pirated versons have been cracked to remove the DRM sometimes weeks before the main release – the ONLY people affected by DRM are the legitimate buyers. DRM is really just painting everyone with the same brush and treating everyone as a criminal/pirater.
The “we need DRM, otherwise we can’t provide all the content we want to!” argument is horrible, stupid, and insulting. DRM does not allow businesses to provide content in new markets. DRM allows businesses to provide old markets in places where they make no sense. Every company which complains they can’t do X without DRM really means they don’t want to do X without magic fairy dust. Meanwhile, everyone else is busy providing X without DRM, and the only difference is the companies which want magic fairy dust aren’t getting paid what they expect.
Monopolies do not exist in modern digital world. People will always acquire the product they want, and if you aren’t willing to sell it, all that means is that people will always acquire the product they want without paying you. A lack of DRM doesn’t make piracy legal, but it sure makes paying for stuff a lot more enjoyable.
To understand why DRM can’t work well in practice needs mature thinking and/or very good abstract thinking applied to real life operating environment. It seems that many people making decisions on using DRM do not seem to get this. The electronic publishing business seems to be going the same route as music and movie industries have been going through. DRM offers made by companies are promise a lot to the publishers. And publishers think that it would be nice if that would work as promised.
The whole idea of DRM relies entirely on security through obscurity, and if you publish a standard then that obscurity is gone. Even with an obscured scheme, if it’s worth it to anyone (ie there aren’t easier ways to get the same content) then someone will reverse engineer the format and work out how to extract the data from it in a usable way. This will always be possible, because the player itself has to get the data into a usable format itself in order to display it. All DRM does is inconvenience legitimate users, pirates will just download media that is not drm encumbered and have a better user experience. Many DRM schemes backfire and give users a lot of trouble.
Reality has already pretty much already rendered DRM as obsolete. DRM does not and has not protected music industry. DRM does not and has not protected video game publishers. DRM does not and has not prevented every significant song, movie, or other work from being easily, readily, and widely available on torrents. So, other than annoy the end users, what purpose does DRM serve?
Besides DRM there are also other methods the content producers have tried with not much help either. Report: Piracy a “global pricing problem” with only one solution tells about that a major new report Media Piracy in Emerging Economies from a consortium of academic researchers concludes that media piracy can’t be stopped through “three strikes” Internet disconnections, Web censorship, more police powers, higher statutory damages, or tougher criminal penalties. That’s because the piracy of movies, music, video games, and software is “better described as a global pricing problem.”
The End of Content Ownership article tells that the cloud, along with subscription and on-demand services, will transform our perception of content access and ownership.
For example Spotify is a digital music service that gives you access to millions of songs for free or with a small fee. Spotify is funded by paid subscriptions, advertisements in the Spotify player for non-subscribers and music purchases from partner retailers. And you can listen a lot of music at Youtube for free as well.
EMC Basics #5: I/O as critical circuits article gives some useful tips on the EMC issues related to inputs and outputs.
Digital inputs/outputs — The key concern for digital interfaces is ESD. A secondary concern is radiated emissions. Radiated susceptibility is rare with digital I/O, although possible at very high RF levels. The solutions for both radiated problems include filtering at the interface and/or or shielding of external cables.
Analog inputs/outputs — The key concern for analog interfaces is RF. High RF levels can cause rectification in the I/O circuits causing errors and/or noise. Typical solutions include high frequency filters and/or shielding of the external cables.
Relay outputs — Since relay drivers are usually digital, the regular digital concerns apply. In addition, inductive transients from the relay coils may pose a self-compatibility problem. Snubber circuits may be needed at either the relay (best) or at the driving circuit on the boards.
Contact inputs — Since the receiving circuits are usually digital, the regular digital concerns apply.
When designing or reviewing circuit boards for EMI, ALL of the I/O circuits deserve EMI attention!
I have some additions to those suggestions:
Opto-isolators (also known as optocouplers) work to protect the receiving system at the expense of the sending system needing to drive the cables/interconnects. They are a great way to isolate digital from power circuits but have limited bandwidths. Fairchild Application Note AN-3001 Optocoupler Input Drive Circuits gives some implementation tips for optocoupler based input circuits.
Using a balanced line interface for sensitive and/or fast signal is a very good idea. Using balanced interface reduces EMI pickup and radiated EMI considerably compared to single-ended signals. Applications like telephone lines, analogue instrumentation, professional audio signals, fast serial bus standards and Ethernet all use balanced interfaces to get good noise performance.
Be careful on the grounding of cable shield when they enter the cabinet. The cable shields should be grounded at the point where they enter the metal cabinet. This will stop the RFI from entering inside the device. This advice applies especially to sensitive analogue circuits like audio interfaces. Proper grounding is essential in keeping RFI and ground loop noise away.
In many power controlling applications you can’t beat a relay for isolation or low on-resistance, as well as low cost. For relay outputs you need to carefully consider the need for snubber circuits. When talking about snubber circuits there are two kind of applications for them: Snubber cuircuit in parallel with the relay coil and snubber circuits in parallel with the relay output.
For the relay coil driven with DC voltage at known polarity an inexpensive diode in parallel with the coil works well. If the relay is switched with AC, the DC polarity is not known or you need very fast operation (parallel diode can slow down relay release time).
You need to consider snubber circuit also at the relay contact side especially if you are switching anything that is even slightly inductive. Relay contacts can arch. The end result of Contact Arc Phenomenon is shortened contact life. In addition to that arching causes lots of electromagnetic interference.
Relay Contact Life article tells that perhaps the most popular method of quenching an arc between separating contacts is with an R-C network placed directly across the contacts. Contact Protection and Arc Suppression Methods for Mechanical Relays gives information how to design a suitable R-C network for quenching an arc.
Some relay users connect a diode across the inductive load to prevent counter-voltage from reaching the contacts. In some application zener diodes are used. The MOV performs in a manner similar to back-to-back zener diodes, and can be used in both AC and DC circuits.
An added benefit of arc suppression is the minimization of EMI. An unsuppressed arc between contacts is an excellent noise generator. Arc may radiate energy across a wide spectrum of frequencies. By suppressing the arc, electromagnetic interference is held to a minimum. By quenching the arc quickly, this action is held to a minimum. The result often is a considerably lessened amount of electromagnetic and radio frequency interference. Contact arc noise can be troublesome to sensitive components in a circuit. In worst-case conditions, EMI can cause unwanted turn-on of IC logic gates, SCRs, and triacs, and can cause damage to other semiconductor devices.
The idea if replacing fluorescent light bulbs with LEDs seems to become popular. There are different kind of products made for that purpose, some are good and some not so good. So I felt it was now good time to test this technology.
LED technology promises to reduce power consumption about 50% of fluorescent bulbs and your replacement period becomes 10+ years. Good promises if those hold true. Modern LED tubes are designed so that they can be just plugged in place of original fluorescent lamp
I have read that a plenty of low quality LED tubes hit the market, some that do not hold their promises and some even potentially dangerous. I think that it is now right time test this myself. My intention on the test was to see how see the LED tube replacement technology nowadays it and get rid of the lamp flickering (tube flickers when you turn on light). The possibility to energy was a secondary option because I live in Finland (cold climate) and the heating the house uses electrical heating, meaning that I would really get energy saving on some summer months when the main heating is not used.
The lamp where I wanted to replace the bulb was in toilet. The first task was to check the power of the original tube and the socket type it used. For socket type identification Light Guide: Compact Fluorescent Lamp Identification was an useful document. The original tube turned to be 18W tube with G24 base.
The replacement bulb I used was G24 13W 52-5050 SMD LED Warm White Light Lamp Bulb (85~265V) ($20.30) from Dealextreme.
Lamp specifications:
- Ultra bright high intensity 52-5050 SMD LED warm white light bulb
- Quality aluminum shell
- Power: 13W
- Voltage: 85~265V
- Color: Warm white
- Connector: G24
What I was first is that this bulb does have bare SMD LEDs that you can see on the front. There is no protective glass/plastic over them. The wiring to LEDs is visible, which seems to be a little bit frightening knowing that those wires can have mains voltage on them (unless the LED power supply is isolated which I quess it not). While bare wiring looks somewhat frightening, the product does not look to dangerous because you can’t in any easy way touch those wires. The LEDs are put so near each other that you can’t touch those wires with your fingers. And in addition to that this bulb will go to the lamp in the ceiling that has a protective cover on this. So electrical safety seems to be OK here.
The bulb worked well when just plugged on the place of the original bulb. No problems worked nicely. This worked well, and no more annoying flashing when light is turned on (fluorescent flashes few time before goes on, this one starts immediately). This bulb gives out equivalent amount of light as the original 18W bulb (looked the same and gave same lux reading with lux-meter on the front).
I did the light measurements with Mastech MS8209 multimeter with lux range front of bulb 50 cm distance from the lamp on the ceiling. When installed inside the lamp, the reading with original 18W bulb was 560 lux and with 13W LED that was 565 lux. The LED bulb itself gave 800-900 lux from 50 cm distance when measured outside the lamp (no ceiling lamp from glass between the LED source and meter).
The light distribution was a little bit different with the original tube and this new replacement, but not too different to cause problems on the application.
The end results is that G24 13W 52-5050 SMD LED Warm White Light Lamp Bulb (85~265V) is cheap and well working LED replacement for G24 fluorescent bulb. Installation is easy, just plug into place. Works as promised.
LED retrofit lamps have started to show up on retail shelves. Many players in the LED industry are giddy about the anticipated growth over the next few years. Nevertheless, the road to success for LED lighting will not be completely smooth, as there are a number of pitfalls to navigate.
Bumps in the road ahead for solid-state lighting article gives a picture of the expected pitfalls. Some of the potential problems ahead are pricing, color quality, thermal management, regulatory, and consumer education. While most of these issues are not technical, the design engineer will nonetheless need to understand them.
While white LEDs are very efficient light sources, converting approximately one-third of the input power into light, the remaining two-thirds is converted into heat in the LED. Currently impossible to passively cool an LED that outputs 1,500 lm (the typical output of a 100-W light bulb) in the physical confines of the normal light bulb size form factor. So at 100 lm/W, about 10 W must be continuously and rapidly dissipated while keeping the LED well below maximum operating temperature (typically approximately 120ºC).
Thermal management will get somewhat easier in the future. As LED efficiencies improve, the thermal management improves by approximately the square of the efficiency, because the total power supplied to the LED decreases and the percentage of heat generated by that input power also decreases by the same amount.
Color quality may be the most difficult problem to solve. The industry has spent tremendous time and expense in measuring and controlling the color variability of white LEDs. But color temperature and tight chromaticity binning don’t tell the complete story, because two light sources with identical chromaticity coordinates may have very different wavelength spectra. LED spectrum is very different from the incandescent’s spectrum. If the spectra are too different, non-white surfaces will appear to be different colors under the two light sources. The Color Rendering Index or CRI is a measure of how closely the perceived color of a surface illuminated by a particular light source will be to the perceived color of the same surface under incandescent illumination. A CRI of 100 is a perfect match. A CRI above 80 for an LED is considered good.
In the short term, LED retrofit bulbs will make the initial splash, but in the long term there are great opportunities for custom LED luminaires. LEDs make possible much more complex form factors and consequently can create more interesting and useable illumination patterns than traditional bulbs and CFLs. Imagine a luminaire that not only is dimmable, but one that you can select the color temperature you desire.
When LED efficiencies reach the 150 lm/W range, it will become feasible to increase office lighting to 1,000 lux, as opposed to the 300 lux now typical in most office spaces.
The growing importance of cloud computing along with the increasing utilization of unified data/storage connectivity and the advent of server virtualization have elevated the popularity of 10Gbps Ethernet.There are several connectivity options are available for 10Gbps Ethernet, both over optical fiber and copper cables.
10GBase-T Technology Revisited article tells that the lack of economical cabling options for 10G Ethernet beyond a single or adjacent rack has led to the popularity of Top-of-Rack (ToR) architectures, in which a stack of rack mounted servers are connected with short cables to a fixed configuration switch in close proximity — typically on top of the server rack.
10GBase-T has promise to change that. 10GBase-T is the fourth generation of IEEE standardized Base-T technologies which all use RJ45 connectors and unshielded twisted pair cabling to provide 10Mbps, 100Mbps, 1Gbps, and 10Gbps data transmission, while being backward-compatible with prior generations.
10GBase-T is arguably the most flexible, economical, backward-compatible, and user-friendly connectivity option available. 10GBase-T allows you to use the existing structured cabling infrastructure and allows cable to reach to the full 100-meter length permitted by structured cabling rules. When compared to other 10Gbps connectivity solutions, one of the most important advantages of 10GBase-T is the ability to communicate and inter-operate with legacy, often-slower Base-T systems.
IEEE 802.3an, 10-Gigabit Ethernet over twisted pair standard, also known as 10GBase-T, was ratified at 2006. Unfortunately this has not led to an immediate proliferation of compliant switches and servers in data centers. However, steady advances in semiconductor lithography, and sophisticated algorithms intended to increase electromagnetic interference (EMI) immunity and lower operating power, will make it more practical. For years 10GBase-T has been considered to be very power hungry and expensive. The reason for this has been the complexity of the signal processing that is needed. The 10GBase-T transceiver uses full duplex transmission with echo cancellation on each of the four twisted pairs available in standard Ethernet cables; thereby transmitting an effective 2.5Gbps on each pair.
10GBase-T Technology Revisited article will explore the basic operation of a 10GBase-T transceiver and the inherent advantages of 10GBase-T technology as compared to alternatives, such as optical fiber and coaxial copper.
One of the arguments against 10GBase-T has been power dissipation, but this perspective is rooted mostly in early implementations of the technology. Recent advances in semiconductor lithography have allowed 10GBase-T transceivers to enjoy a dramatic reduction in the power they dissipate during normal operation. From a per-port power of over 6W just a few years to typical Active power dissipation of 1.5W. When utilizing the EEE power saving algorithm with typical computer data patterns for 30-meter reach, newest ICs will dissipate only 750mW.
Meego will will be merged out of existence. MeeGo will become Tizen. Tizen is a software platform and a mobile and device operating system based on Linux and other popular upstream projects. According to Intel, Tizen will build upon the strengths of both LiMo and MeeGo and Intel will work with MeeGo partners to help them move from MeeGo to Tizen.
The Tizen project is hosted at the Linux Foundation and offers an operating system and an HTML5 development environment within which applications can be produced to run on multiple types of hardware. The Tizen application programming interfaces are based on HTML5 and other web standards, and it is anticipates that the vast majority of Tizen application development will be based on these emerging standards. Tizen will provide a robust and flexible environment for application developers, based on HTML5 and Wholesale Applications Community (WAC). The Tizen SDK and API will allow developers to use HTML5 and related web technologies to write applications that run across multiple device segments, including smartphone, tablet, smart TV, in-vehicle infotainment, and netbook. So the application development is expect to shift from Meego/Qt now to Tizen/HTML5.
For those who use native code in their applications (small percentage of the applications), the Tizen SDK will include a native development kit.
Tizen sounds an awful lot like WebOS to me. Why do we need more Linux OS? Will this really replace the ones it is combining together or fragmenting the market more? The situation in mobile Linux field seems to be pretty similar to what happens at xkcd:Standards comic to standards.
Meeting the requirements for video-grade Wi-Fi Access Points article gives some interesting facts on transporting video over wireless LAN. Users are coming to expect a wireless video experience equivalent to video consumption over wires.
Traditionally a Wi-Fi device was measured according to its receiver performance, using metrics such as receive sensitivity. With video delivery, transmitter performance is ultimately measured according to user experience. Raw throughput is no longer an adequate metric for measuring wireless network performance, as was the case with internet data traffic.
If we use around 10-20 Mbps per HD stream, multiple HD stream delivery requires no more than 40-80 Mbps of actual throughput. The main challenge is to deliver this relatively modest throughput consistently and robustly across an entire home to multiple nodes. Quality-of-service (QoS) related metrics, such as packet loss, delay and jitter, to which HD video is highly sensitive, must be optimized as well, sometimes at the expanse of raw throughput.
This must be accomplished over a constantly changing and hostile wireless fading, interference prone channel. The challenge becomes converting an unpredictable medium into a controlled and managed one. We can’t control everything, but we need to make the system to work well enough to be enjoyable.
One day I had an old flashlight that had burned light bulb on it. It was a small cheap model powered with two AA batteries. I could fix it with new light bulb, but going through the trouble of trying to find exactly suitable replacement light bulb felt like more than the value of the flashlight.
If I need to replace the bulb with new one, why not convert the lamp to use LED instead.The lamp runs on two AA batteries in series. They give out around 3V voltage. That’s about the same voltage drop many white LEDs have (typically 2.8-3.5V or so). I had earlier found out that some white LEDs can be directly powered with 3V battery without any current limiting electronics. You just need to find out suitable LED. Some small LED lamps are driving white LED with 3V lithium button cells without a resistor! There are LEDs out there with internal resistors. And there are some LED that just work.
The general advice is that DO NOT use LEDS without a current limiting resistor in series with the LED. The forward voltage rating is TYPICAL and can vary from part to part, so while some LEDs may work fine just connected to a battery of the proper voltage, others will be easily over-driven and be destroyed.
Driving an LED with or without a resistor article on the other hand says that if you are able to run your complete circuit with the same voltage as forward voltage of the LED, perfect. No resistor needed. If you try to run run a 3.2 /3.4 volt warm white of a 3 volt power supply, you will get light but not the maximum amount. But usually enough for small flashlight application anyways. I had even used this idea on my LED light ring for macro photography project, so I was pretty comfortable with this idea.
Now all I need was to find suitable LED from my electronics junk box. I could check the datasheet or do measurements to verify suitability of the LED. It seemed that quite many white LEDs can be run from 3V battery without limiting resistor. But it is best to verify with measurement that things work well. I took a random white LED and put it to Kemo M087 LED testing box. I tested the voltage drop of the LED and different currents from 5 mA to 20 mA (and very quicly with 50 mA). The LED seemed to take somewhat less than 3V at 5 mA and 10 mA. At 20 mA the voltage drop was around 3.2V. At 50 mA the voltage drop was around 3.4V. With this data I could expect that with two new AA batteries in series (gives around 1.6V each) the LED would take around 20 mA current and the current would drop from that when batteries wear out. With this data it seems that this LED would work here.
The next step was just building the LED bulb replacement. Here is a small DIY flashlight bulb LED replacement. It consists of the lamp base (small edison base from old broken bulb), 5mm white LED, solder tin and hot glue. The LED anode goes to the center of the light bulb base.
Here is picture of my LED bulb in the flashlight in use.
Now I have a nice working flashlight that is not very bright, but that has a very long battery life.
If this modification looks interesting, then you might wonder how to convert lamps with different number of batteries to LED lamps. With flashlights that use three batteries or mode, the standard method to use would a white LED + suitable current limiting electronics does job. A resistor will work nut switch mode current source is better. For 20 mA LED and 4.5V operation voltage a 75 ohms or 82 ohms resistor will do. For other operating voltages and LED currents, do your own LED resistor calculations.
If your flashlight uses just one 1.5V battery, you will need a switch mode power supply that boosts the battery voltage to over 3V and limits the current. Joule Thief is a nickname for a minimalist self-oscillating voltage booster that is small, low-cost, and easy-to-build. It can use nearly all of the energy in an electric battery, even far below the voltage where other circuits consider the battery fully discharged (or “dead”). The energy is converter to current and voltage suitable for driving white LED. Make a joule thief if you want to drive white LED from one 1.5V battery.
