The first law of musical robotics: rock hard. Rock Robots: PAM Can Seriously Shred, Open Source MARIE Could Do Even More article shows you some interesting videos on robotic musical experiments. Here is one of them.
Archive for December, 2010
Rock Robots
Friday, December 31st, 2010EU standards for common mobile phone charger
Thursday, December 30th, 2010The European Commission supports industry’s commitment to provide a common charger for mobile telephones. Commission welcomes new EU standards for common mobile phone charger: European Standardisation Bodies CEN-CENELEC and ETSI have now made available the harmonised standards. The industry commits to provide chargers compatibility on the basis of the Micro-USB connector. The technical number for this micro-USB charging standard is EN 62684.
The European Commission expects the first common chargers and mobile phones compatible with the new standards to reach the European market in the first months of 2011. Sony-Ericsson, Nokia, Apple and all the others will now have about a year until the 1st of January 2012 to make sure that the majority of all phones will support the new standard.
Technical requirements: Output Voltage Range: 5V +/-0.25V from no load to maximum output current measured at the Micro-B plug of the captive cable or on Standard-A receptacle in case of detachable cable. Output Current Range at 5V +/-0.25V voltage range is 500 mA to 1500 mA (maximum 1.5A load at voltages below 4.75V). Output Voltage Ripple 80 mVp-p.
EPS shall short the D+ and D- lines with a resistance not greater than 200 ohms (per USB Battery Charging Specification).
The charger converts 90V-264VAC at 50-60Hz into 5VDC, 500-1500mA. The galvanic isolation required for user safety also isolates the charger output from earth ground, although there still exists capacitive coupling between the primary and secondary through the transformer. Output of the power adapter shall meet LPS, SELV, non-hazardous energy requirements. Maximum Current under Single Fault Condition shall not exceed 3A. The power adapter shall meet Class II requirements with max leakage current not exceeding 90 micro-Amps.
The power output to the mobile phone is isolated “floating” type. It should be noted that the common-mode noise exists independent of a well-regulated DC output, as the positive and negative DC output lines, the USB cable, and the Mobile Terminal are all pushed “up” and “down” together.
This is nothing new, just now well documented what happens. This same happens with practically any today’s mobile phone charged based on switch mode power supply technology. Mobile phones need to be designed so that they can live with it.
There is one Technical requirement that sounds quite hard at first but makes sense for end user point of view: The charger shall not be damaged as a result of any electrical overload, over-temperature condition or any short circuit condition.
The common charger will make life easier for consumers, reduce waste and benefit businesses. Please note that earlier there has already been a voluntary agreement on cell phone chargers in EU using the same connector and China implements standard USB charger for all mobile phones.
Surveillance camera image processing
Monday, December 27th, 2010Use FPGAs for stunning surveillance camera images is a cool article on image processing performed inside modern surveillance cameras. The “stunning images” are made possible by utilizing the latest in high definition high dynamic range CMOS image sensor technology. The “valuable information” is provided by adding intelligence in the camera that can look for the image and process it to show the interesting details well.
A typical image sensor can only reproduce about 72dB of dynamic range (around 12 bits). Today’s latest image sensors use adaptive non-linear exposure techniques that can exceed 115dB of dynamic range (19-20 bits).
Even if you increase the dynamic range of the camera, the the displayed output is going to be limited to only 8-10 bits of brightness (luminance) information per pixel. A dynamic range compression algorithm needs to be used to convert the high dynamic range to something that displays well on limited dynamic range display. The process is somewhat similar to processing used in High dynamic range imaging or digital image artist do to their photographs.
With more dynamic range in the image sensor and right processing, the details in the darkest of areas along with the brightest of areas can be reproduced without compromising either extreme. Your your eye based visual system is actually doing something very similar to this, but you’re not actually aware of it (in that way eye is covering up to 160dB of dynamic range).
Real time image dynamic range processing requires massive, flexible parallel processing in a small, power-efficient footprint. FPGAs are excellent devices to enable cameras with these new features. The FPGA is mentioned on the article very often because the guy who wrote the article seems to be FPGA guy (Marketing Manager of Altera, a company that makes FPGA ICs).
Image processing could be also done using ASICs or CPU. At the moment a lot of ASICs inside digital camera do similar or even more complicated computations, but they are not reconfigurable. Modern PC CPUs and GPUs are very powerful computing engines, so a lot of image processing can be done with them if you can wait for short time for the processing to happens. Amazing amount of image processing can also be done using a GPU in CUDA or OpenCL. GPUs are nowdays used to build supercomputers so lots of computing is available on that way as long as the device does not need to be very small and can consume lots of electrical power.
Holiday project ideas
Wednesday, December 22nd, 2010Lego Holiday Ornament page shows how to build a set of fun holiday items with Lego. The first object you will tackle is an ornament for your tree. The project web page contains model file for free Lego Digital Designer 4.0 software.
Geek Christmas Ornaments: Part 9 web page shows how to make keyboard circuitry sheet Christmas ornaments. Just take apart an old keyboard, remove the flexible circuit-board sheet from under the keys and cut them to right size pieces to make interesting looking ornaments.
LEDs can be used to make all kinds of high-tech decorations for the holidays. Make a hackable LED ornament web page shows how to make an LED ornament that lets you shuffle different colours and types of LEDs at any time depending on what you want. How to make high-tech LED decorations for the holidays web page present two open-source, do-it-yourself, microcontroller-powered holiday electronics projects: A micro-readerboard Christmas tree ornament and a mini-LED Hanukkah menorah. DIY holiday ornaments web page gives you some more links to similar projects.
My Christmas Lights display and controlling them discussion board posting from few years back will give you links to nice and otherwise interesting Christmas Lights displays. You can find lots of light controlling ideas from discussion board Home Automation section. Feel free to post there more links and ideas. Happy holidays.
Energy Efficient Ethernet
Sunday, December 19th, 2010Ethernet link speeds of 100 megabits per second or even 1 Gbit/s per second are typical in today’s LANs. When everything is wired to Ethernet LAN very many LAN connections are needed and they consume some power. And the faster the Ethernet connection is, typically more power it consumes.
IEEE Spectrum Energy-Efficient Ethernet article tells that Ethernet connections waste lots of watts and it need not necessarily need be so. On average, people use their Ethernet links at full throttle less than 5 percent of the time. But the circuitry on the network-interface controller, the chip that connects your computer to the network, is always running at full speed, thus wasting power.
One seemingly simple solution is to adapt the Ethernet link’s speed to match a device’s needs. This concept is called Adaptive Link Rate. The problem in this concept is that switching between Ethernet speeds is time-consuming. When you change link rate today, you have to drop the link and reestablish it, which takes up to 2seconds.
Another concept is called low-power idle, it proposes transferring data on an Ethernet link at the highest possible rate and then putting the network controller chip into a sleep-like state. The trouble is that turning on a dormant network card quickly is a challenge, but it is easier than switching between rates.
Wikipedia Energy Efficient Ethernet article tells that Energy Efficient Ethernet, also known as IEEE 802.3az, is a set of enhancements to the twisted-pair and backplane Ethernet networking standards that allow for less power consumption during periods of low link use. The goal is to reduce power use by 50% or more, while remaining fully compatible with existing equipment. The power reduction is accomplished in a few ways:
- For 100 Mbit/s and gigabit speed links, Ethernet chips that don’t have data to send would put the physical layer of the system into sleep mode. Gigabit interface card might be able to reduce its power by up to 1.5 W.
- For 10 Gbit/s links, speeds are stepped down to slower speeds saving 10 – 20 W per link (twisted pair Gbit/s links consume typically 15W or so power)
- A new lower voltage mode was added to 10Base-T (lower voltage used when full voltage is not needed for example on shorter links)
There were some companies introduced technology to reduce the power required for Ethernet before the standard was set. The best known of them was D-Link’s and Broadcom’s Green Ethernet, which is a superset of the draft 802.3az. Green Ethernet was first employed on home switches and smart switches. D-Link claims that a power savings of up to 45 – 80 percent can be made using its Green Ethernet switches, but I think in real life applications the savings will be somewhat less than those promises.
Broadcom delivers energy-efficient Ethernet silicon article about Broadcom’s portfolio of available silicon supporting the newly ratified IEEE 802.3az-2010 Energy Efficient Ethernet (EEE) standard and proprietary AutoGrEEEn technology. Broadcom Infrastructure & Networking Group, said in a press release, “Energy efficiency is of crucial importance to our customers and to the networking industry as a whole.”
The power savings for an individual consumer level device are likely to be modest compared to the cost of device or the embodied energy, so turning off existing devices when they are idle is likely to be a more immediate savings. If Energy Efficient Ethernet is widely incorporated into new systems, it could reduce networking power requirements as systems are replaced. Green Ethernet Technology is pushing into networking hardware market.
Symbian problems and changes
Tuesday, December 14th, 2010Nokia, once a world leader, is losing popularity to rising stars like Google Android and Apple iOS. Android phones are selling more than Symbian phones. Google activates 300,000 phones every day and Nokia Symbian phones somewhat less. What has happened to the old clear smartphone OS leader Symbian.
Why Symbian failed: developers, developers, developers article tells that the reasons why Apple succeeded in creating a smartphone market have now become conventional wisdom. iPhone was designed to be a mobile computer first, not a phone. Same applies to Android phones.
There’s also a similar agreement on the reasons why Nokia missed out. Nokia’s design philosophy was that smartphones were phones first, not computers. Nokia is has been very reliant on Symbian, but had neglected to develop and polish the user interface over the years.
One reason for problems could have been in the software architecture. The basic Symbian OS was pretty well optimized to run on even pretty low power CPUs (uses less processing power than Linux or iOS for the same tasks), but to accomplish this Symbian went its own way with just about everything. And these new ways were so damned hard to learn, most people just didn’t bother. The sluggish performance you see on your Nokia phone today is claimed to be a direct result of developers doing things in non optimal way.
Your platform can be as clever as you like, but until it’s so intuitive that developers take to it like a duck to water, the cleverness will all lie unused, gathering dust. As you know in real life a lot of real production code is bashed together by short-term contractors and people new to a platform.
Many mobile phone manufacturers that ealier used Symbian are leaving the boat, and Nokia seems to be the only one player left on the boat. Nokia is reducing hundreds of people in Finland on Symbian smartphone development. Nokia announced 1,800 job cuts worldwide in October.
Nokia is closing Symbian Foundation and taking the development to it’s own hands. This sounds pretty much like the end of the open source Symbian era. Symbian Developer web site is closing on December 17th. So if you want something from this what seems to be a slowly sinking boat you have only few days to get that…
Symbian’s future is now reliant on the success of the Symbian^3 platform. The N8 handset is the first Symbian^3 phone, catching headlines.
Prototyping robotic systems
Monday, December 13th, 2010A working robotics prototype involves mechanical, electrical, and software design. Five golden rules for prototyping robotic systems article shares some lessons learned while designing an autonomous robotic helicopter.It shows that a well-thought-out plan for prototyping can significantly pay off in the long run and can be even more important in robotics applications than in other fields. Keeping the five rules in mind should help you quickly move from the prototype to the next step of the design process.
VGA is dying?
Thursday, December 9th, 2010Many modern PCs still use the over 20 year old 15 pin analogue VGA connector to connect the display to PC. The VGA connector carries the video signal in RGB format, which is a bit outdated in the world where the graphics card and display devices are all digital. Most Windows PC builders have been clinging to VGA to support legacy displays, especially in corporate environments where companies have often been hesitant or unable to update to modern screens and projectors.
The digital display interfaces have thought to replace the analogue VGA interface long time ago, but it has not happened yet. But maybe after few years it might happen. Apple was one of the first to abandon VGA in its products, adopting first DVI and later the DisplayPort and derivative Mini DisplayPort standards for its notebooks and desktops.
AMD, Intel, PC builders plan to drop VGA by 2015 article tells: AMD, Dell, Intel, Lenovo, Samsung and LG on Wednesday said they plan on focusing on putting digital DisplayPort and HDMI connections into their computer products. They hope to drop analog VGA and LVDS connections in AMD- and Intel-based products by 2015.
The article says that AMD CTO of the graphics division Eric Demers believed DisplayPort 1.2 is the future interface for PC monitors and HDMI 1.4a is the next step for TVs. DisplayPort is backwards compatible with VGA and DVI thanks to adapters.
Relay Contact Life
Tuesday, December 7th, 2010Tyco Electronics has an interesting application note named Relay Contact Life. The Relay Contact Life document outlines the basics of relay contact selecting, properties of different contact material and strategies for protecting relay contacts.
There is no such thing as a universal relay contact. Relay contacts are available in a variety of metals and alloys, sizes and styles for a good reason. The relay user should select contact materials, ratings, and styles to meet, as precisely as possible, the requirements of a particular application. Failure to do so can result in contact problems and even early contact failure.
In many applications, the relay contacts may be subjected to punishing current surges which can drastically reduce their life if not properly selected for the application. Measure the current inrush of the circuit to be switched before specifying the relay.
The electrical life expectancy of general purpose and power relays is generally rated to be 100,000 operations minimum, while mechanical life expectancy may be many times higher. Contact life is terminated when the contacts stick or weld, or when excessive material is lost from one or both contacts and a good electrical make is not possible. The reason electrical life is rated so low compared with mechanical life is because contact life is application dependent. When a set of contacts switches a load of less than rated value, contact life may be significantly greater.
When you need to switch the signal very often consider the possibility to use Solid-State Relay. CP Clare application note Advantages of Solid-State Relays Over Electro-Mechanical Relays tells that electronic designs can take advantage of the improved performance of solid-state relays (SSRs) relative to that of electro-mechanical relays (EMRs) that perform the same circuit function. SSRs can usually be specified with confidence at actual load voltages and currents. Contact erosion is not a concern because there are no contacts. The absence of contacts and moving parts means that SSRs are not subject to arcing and do not wear out. SSRs have many good properties but they have also their disavantages, so they do not fit to all applications.
New main index page
Thursday, December 2nd, 2010A new ePanorama.net main index page is now on-line. The new index page tries to fit all the most often needed links in the one web browser screen without need to scroll the page.
The new page contains a daily changing picture element. That picture element is often a photograph on more or less electronics related topic or at some days it can be a drawing (for example a schematic). Enjoy the new changing content on the main page. The daily pictures are randomly selected from the daily picture gallery. Most pictures there are taken by me or previously published on the site.
PS. If you feel lost in new main index page, you can still use the old main index if you want. I have not thrown that page out, just changed it’s address.
