From jcea at argo.es Fri Dec 7 11:22:34 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Fri, 07 Dec 2001 11:22:34 +0100 Subject: [Domotica] Is Embedded Linux a Bust? Message-ID: <3C10986A.BF290901@argo.es> http://www.embedded.com/story/OEG20011130S0034 Embedded Systems Programming Editor in Chief Michael Barr recently forwarded me an intriguing letter from a consultant who had attempted to build a business helping companies incorporate Linux into their embedded systems. The effort was a complete failure; a year of work had turned up only two companies actually using Linux in the embedded arena, so the consultant returned to traditional real-time operating systems where there's plenty of work and lots of money. What gives? If you believe the magazines, it appears anyone not using Linux is a dinosaur, an atavistic throwback doomed to write miserable little 8051 assembly language programs forever. At the local bookstore an entire shelf of computer magazine headlines scream ?Linux Forever!? All tout this OS as the solution to everything that ails us, from hackers to global warming. Unfortunately, Linux is an unassailable icon. Those who cast aspersions on it are immediately branded as wrong-thinking heretics. Yet it's just an operating system. That's it -- a tool, something that allows us to build real systems. In the embedded world Linux is even less than an OS; it can't even manage real time events -- at least not in the native distribution. Unless Linux is bolted on top of a traditional embedded RTOS, your system might have a killer file system but be unable to handle asynchronous events in a timely manner. In my travels around the embedded world I see a huge number of developers working with all sorts of real time operating systems, from very simple home-brew taskers to complete top-of-the-line commercial products with protocol stacks and a wealth of features. But Linux seems to be a phantom OS. Plenty of folks have adopted it as a development platform, but only rarely do I see it incorporated into a product. Sure, there are some notable exceptions. Some set-top boxes, PDAs, and other products are being shipped today with Linux kernels. But Linux-based seem to be in the minority, with traditional RTOSes still, by far, dominating the OS space. Much as politicians are led by their polls, publishers use extensive surveys to see where the market is heading and what sort of editorial content best addresses readers' needs. But surveys are notoriously fickle. The 2000 ESP subscriber study showed that 12% of the 525 respondents used Linux in their 16- (!) or 32-bit systems in the last year. Thirty-eight percent are considering it. With almost 100,000 embedded design starts each year, that suggests a huge market, enough to make any embedded Linux provider salivate and venture capitalists feed the frenzy with wild abandon. But almost a year has elapsed since that study, and there's no way, based on my imprecise observations, that 30 to 40,000 projects were done this year with this OS. Lineo announced a layoff in September. One of MontaVista's white papers discusses 60-microsecond interrupt latencies on an 800MHz Pentium. Yikes! Is that CPU really indicative of the embedded world? I doubt it. Linux is a big beast that needs a lot of memory and processor cycles. It does bring some pretty substantial benefits to some systems: communications stacks, a fabulous file system, and Unix-like interactivity and reliability. But is this a substantial part of the embedded space? What roll do you think Linux will play in embedded systems development in the near future? Jack G. Ganssle is a lecturer and consultant on embedded development issues. He conducts seminars on embedded systems and helps companies with their embedded challenges. He founded two companies specializing in embedded systems. Contact him at jack at ganssle.com. His website is www.ganssle.com. Take the poll Reader Feedback I totally disagree. First of all, the very first question we must answer is this: what is embedded? It isn't what it used to be 10-15 years ago. In the past, there was no way you could even talk about an OS with the 8051 or any other processor, because there would be scarcely any memory for the application on a target yet alone for the OS. Now, things are changing and from where I am standing, the line that separates "embedded" and other types of systems is quickly fading away. So, it is no longer a constraint to require more power from hardware, in fact it is a necessity! My second point is the level of support you would be receiving for any commercial RTOS. Most of the time, you have to deal with the marketing people who don't really know what they are talking about, and whatever you ask, they will answer as they have been taught: a big yes! Wish things were so bright! But when the thing starts breaking down, they will not be there for help and it would take infinitely long for you to get to the real people who know their thing. This is not the case for Linux. You will get help from the user community without any cost, and people will share their code with you. Just for the fun of it! If you want to change things, you are absolutely free to do so. With a commercial OS, would the writer care to give an example on any of these advantages? From my point of view, it's only about one thing: making things better and Linux leads the way on that! Utku K. I find it amazing that someone could spend a year searching and only turn up 2 companies doing embedded Linux work. My company doesn't cater to the embedded Linux niche, and over the same time period we've gotten two clients locally in a town of 100,000 that are doing embedded Linux work. In both cases, they came to us... I obviously can't critique his work-finding plans, since no details were given. It just seems odd. Sean Reifschneider MTS tummy.com, ltd. Politics and perception -- from what I have seen, these are the two biggest reasons that Linux is not more frequently being adopted into target embedded systems. First, politics: I think that you will find many company's will generally be in favor of using a robust, yet free operating system as opposed to paying money for one, hence the high polling numbers. In contrast a high interest from individuals being polled, I think you will find that corporate support will slack off considerably when it means that a corporation will need to come out and support an operating system in direct competition with, say, Wind River. What Company really wants to damage their relationship with their current OS vendor? The company I just left has, in the past two years gone through not one but two Linux vendors and claims to support Linux on their target systems. However, never have they shipped a Linux based product, and in that two years, I believe I have seen 1 small press release on the subject announcing a limited partnership. Not surprisingly, the have a long-standing partnership with other OS vendors who have no interest in putting up with competition. Second, perception: Linus Torvalds wrote his first post regarding Linux to comp.os.minix on August 25, 1991, so to most of the senior engineers who are making the "what OS do we use" decision, Linux is a baby. These people have cut their teeth on VxWorks, Nucleus, etc. The marketing team for these more established OSes have marketing down to a science. Talk to a senior engineer at your company and ask him if he or she would want to use Linux in the next product you put out. I think you will find that these more senior people are interested in Linux, but are also frightened that Linux will not have the same features or abilities that your more well known OSes do. Its most likely an incorrect belief, but nevertheless, Linux is still new and strange to the men and women making the big decisions. And the Marketing groups from the companies that charge 50K for a yearlong OS license aren't clearing anything up for them. That all being said, in conclusion: Politics and Perception have one shining attribute that squarely comes down in favor of Linux: they change 10-15 years from now, when you, I, and the other new kids on the block are the ones figuring out what exactly this product should look like, read this article again. My money says you'll wonder why anyone ever paid for an OS. Neil Horman Software Engineer LVL7 Systems I am currently working on a Linux based embedded project. It started in March '01. Originally it was to be the development and support system for the deployed LynxOS systems. There were so many issues with LynxOS, that we are looking to replace the fielded systems with Linux systems. Already the customer has proposed a low cost gateway system using Linux. The LynxOS just costs too much. There have been issues that we have run into using LynxOS, that we could have probably resolved using the source code, but it wasn't available. Waiting for the folks From Lynx to get the fix take care of is very time consuming. I had an issue with the semaphores in Linux, a couple web searches, and I found the solution, a small patch. Sure I gotta compile it in, but at least I have an answer today! Linux will happen. Tom Brusehaver Contract Engineer -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Fri Dec 7 11:35:15 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Fri, 07 Dec 2001 11:35:15 +0100 Subject: [Domotica] La =?iso-8859-1?Q?tecnolog=EDa?= PLC hace real Internet a =?iso-8859-1?Q?trav=E9s?= del cable =?iso-8859-1?Q?el=E9ctrico?= Message-ID: <3C109B63.C5EE7FE0@argo.es> http://www.iblnews.com/news/noticia.php3?id=24169 La tecnolog?a PLC (Power Line Communications) posibilita la transmisi?n de voz y datos a trav?s del tendido el?ctrico de baja tensi?n. Bajo esta tecnolog?a cualquier enchufe de la casa se convierte en una conexi?n potencial a Internet, telefon?a y datos. El hecho de que en todos los hogares del mundo haya un enchufe provoca que la tecnolog?a PLC se convierta en la pieza clave de una nueva "revoluci?n industrial" e Internet se convierta en lo que en un principio todos imaginaban que ser?a. As?mismo, la tecnolog?a PLC se perfila como la "bestia negra" del resto de las tecnolog?as alternativas cuya finalidad es la transmisi?n bien de voz, bien de datos o bien de voz y datos. Viernes, 7 diciembre 2001 ALVARO CAMPUZANO CAMPOS, IBLNEWS PLC significa Power Line Communications y se puede definir como una tecnolog?a de acceso que utiliza la red el?ctrica de baja tensi?n (aquella que llega a los hogares e industrias) para la transmisi?n de voz y datos. La tecnolog?a PLC est? enfocada a dos tipos de servicios independientes pero complementarios: - La red de acceso, como m?todo para dar servicio en el bucle final de abonado. - In-home, para crear redes LAN a trav?s de la red el?ctrica de los hogares, lo que permitir?a prestar servicios de dom?tica. Al llegar la tecnolog?a PLC hasta el enchufe de las casas e industrias, las compa??as el?ctricas tienen todas las cartas en sus manos para dominar, sin cavar una sola zanja, lo que en telecomunicaciones se llama la "?ltima milla" o el acceso final al usuario (abonado) ?C?mo funciona y qu? aparatos se requieren para que el usuario pueda disfrutar de la tecnolog?a PLC? En palabras de Francisco de la Pe?a, presidente de Comunik y profundo conocedor de la tecnolog?a PLC, ?sta "funciona desde un nodo conectado a Internet en la subestaci?n el?ctrica o centro de transformaci?n, lugar en el cual se encuentra la cabecera PLC que realiza la conversi?n entre la se?al ?ptica del backbone de la red a la se?al el?ctrica utilizada en PLC. Desde este punto hasta el hogar, el cable el?ctrico transporta energ?a y datos, los cuales han de ser le?dos por un Chipset o electrom?dem colocado en cada aparato dom?stico. Dependiendo de la distancia entre la cabecera PLC y el usuario, ser? necesario la utilizaci?n de equipos de repetici?n. Esta distancia es de unos 300 metros". As? pues bajo la tecnolog?a PLC cada enchufe del hogar/empresa se convierte en un punto de acceso universal de tal modo que con un enchufe se puede alimentar el ordenador, navegar por Internet y hablar por tel?fono al mismo tiempo. ?Es una tecnolog?a cara de desarrollar e implementar? "El coste de implementaci?n es muy inferior al resto de tecnolog?as actuales, ya que no es necesario el cableado de edificios, ni levantar calles. Si bien es una tecnolog?a cara, los costes por hogar/empresa conectada bajaran a medida que la tecnolog?a se generalice. Por otra parte su relaci?n coste/servicio es inferior con respecto al resto de tecnolog?as de acceso a Internet existentes", en palabras de Francisco de la Pe?a. Desarrollo del PLC en Espa?a "En Espa?a Ds2 es la ?nica empresa que desarrolla esta tecnolog?a, con un rendimiento de sus soluciones mucho m?s alto que el resto de las empresas del mercado a nivel global. As?, ds2 ha logrado una velocidad de transmisi?n de datos te?rica de 45 mb/sg, siendo la velocidad de campo alcanzada de 17 mb/sg. En cuanto a las compa??as el?ctricas, todas las grandes en Europa est?n plante?ndose la prestaci?n de un futuro servicio PLC y ya se encuentran en fase piloto"., indic? Francisco de la Pe?a. En lo referente a compa??as extranjeras, existe la empresa suiza Ascom que fabrica 24.000 m?dems mensuales con velocidades de 2'25 mb/sg y tambi?n la empresa israel? Main.Net, proveedor de la empresa alemana MVV, con 600 clientes conectados y que ofrece velocidades de 1'5 mb/sg. As? pues, la tecnolog?a PLC se est? desarrollando en distintas partes del mundo pero todas ofrecen velocidades inferiores a la alcanzada por la empresa valenciana Ds2. En cuando a las compa??as el?ctricas, todas las grandes en Europa est?n plante?ndose la prestaci?n de un futuro servicio PLC y muchas ya se encuentran en fase piloto. En lo referente a Espa?a, la el?ctrica Iberdrola Redes ha establecido una alianza con la empresa israel? Nams, mientras que Endesa est? desarrollando experiencias piloto con diferentes tecnolog?as: la perteneciente a la empresa suiza Ascom y la perteneciente a la empresa valenciana Ds2. En ambas experiencias, los servicios prestados fueron los siguientes: telefon?a sobre Protocolo de Internet (IP), acceso de alta velocidad a Internet y servicios de multimedia tales como v?deo y audio a la carta as? como videoconferencia. Uni?n Fenosa tambi?n ha realizado pruebas piloto utilizando la tecnolog?a de la empresa israel? Main.Net e Hidrocant?brico utiliza la tecnolog?a de la alemana RWE. Inconvenientes del PLC El cable el?ctrico es una l?nea met?lica recubierta de un aislante. Esto genera a su alrededor unas ondas electromagn?ticas que pueden interferir en las frecuencias de otra ondas de radio. As?, existe un problema de radiaci?n, bien por ruido hac?a otras se?ales en la misma banda de frecuencias como de radiaci?n de datos, por lo que ser? necesario aplicar algoritmos de cifrado. No obstante, la radiaci?n que produce es m?nima, la potencia de emisi?n es de 1mW, muy por debajo de los 2W de telefon?a m?vil, adem?s cumple todos las normativas a nivel europeo, adem?s de cumplir la estricta normativa alemana. Otro problema es la estandarizaci?n de la tecnolog?a PLC, ya que en el mundo existen alrededor de 40 empresas desarrollando dicha tecnolog?a. Para solventar este problema, la organizaci?n internacional PLCForum intenta conseguir un sistema est?ndar para lo cual est? negociando una especificaci?n para la coexistencia de distintos sistemas PLC. Ventajas del PLC Las ventajas competitivas del PLC son: * Utiliza infraestructura ya desplegada (los cables el?ctricos). * Cualquier lugar de la casa con un enchufe es suficiente para estar conectado. * Coste competitivo en relaci?n con tecnolog?as alternativas. * Alta velocidad (banda ancha) * Suministra m?ltiples servicios con la misma plataforma tecnol?gica IP, as? un s?lo m?dem permite acceso a Internet, telefon?a, dom?tica, televisi?n interactiva. seguridad, etc..) * Instalaci?n r?pida. * Conexi?n permanente. La gran ventaja del PLC radica en que se constituye como una alternativa a los cables telef?nicos. En Espa?a, por ejemplo, m?s del 50% del mercado de telecomunicaciones est? asociado a los segmentos residenciales, peque?as oficinas y oficinas en casa, las cuales est?n cubiertas en su mayor?a por Telef?nica y las operadoras de cable apenas lo cubren. Es decir, no hay competencia y por lo tanto la tecnolog?a PLC se pueden convertir en una alternativa real al resto de tecnolog?as alternativas. -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Fri Dec 7 11:43:25 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Fri, 07 Dec 2001 11:43:25 +0100 Subject: [Domotica] Slashdot | Living in a Linux Embedded World Message-ID: <3C109D4D.368624FE@argo.es> http://slashdot.org/article.pl?sid=01/12/05/1724243 -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Mon Dec 10 11:36:16 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Mon, 10 Dec 2001 11:36:16 +0100 Subject: [Domotica] Un =?iso-8859-1?Q?peque=F1o?= proyectillo... Message-ID: <3C149020.2BB079F2@argo.es> http://jukebox-control.sourceforge.net/ -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Mon Dec 10 14:01:19 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Mon, 10 Dec 2001 14:01:19 +0100 Subject: [Domotica] Cableado de una casa nueva Message-ID: <3C14B21F.DF8BCBBD@argo.es> http://slashdot.org/article.pl?sid=01/12/09/1847251 -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Tue Dec 11 13:18:37 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Tue, 11 Dec 2001 13:18:37 +0100 Subject: [Domotica] Building a Cheap Oscilloscope Using Your PC? Message-ID: <3C15F99D.DA54F33B@argo.es> http://slashdot.org/article.pl?sid=01/12/07/191220&mode=thread -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Thu Dec 13 21:04:52 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Thu, 13 Dec 2001 21:04:52 +0100 Subject: [Domotica] =?iso-8859-1?Q?Electrodom=E9sticos?= inteligentes en HomeTech Message-ID: <3C1909E4.B9ED5B3E@argo.es> http://www.idg.es/pcworld/noticia.asp?idn=20242 >>>>> Electrodom?sticos inteligentes en HomeTech Durante la celebraci?n de la feria, en Berl?n, se mostrar?n diversos prototipos de electrodom?sticos conectados en red. El primer Escaparate internacional del electrodom?stico, HomeTech, tendr? lugar del 27 de febrero al 3 de marzo de 2002 en Berl?n. Organizado por Messe Berlin en colaboraci?n con el CECED (Confederaci?n Europea de Fabricantes de Electrodom?sticos), contar? con m?s de 550 expositores procedentes de 40 pa?ses. El evento estar? abierto al p?blico los d?as 2 y 3 de marzo. De entre las ?reas tem?ticas que se abordar?n en HomeTech, destaca ?automatizaci?n del hogar?, en la que se mostrar?n las ?ltimas novedades en electrodom?sticos a los que se aplican las m?s modernas tecnolog?as inform?ticas y de la comunicaci?n, sensores e Internet. Pese a que algunos de los nuevos productos basados en la utilizaci?n de la Red est?n a?n en fase de pruebas, algunos de estos aparatos se mostrar?n en la Feria. Es el caso del frigor?fico con mando electr?nico m?vil, conectado inal?mbricamente a Internet. Este aparato permite desde cualquier lugar de la casa acceder a toda la informaci?n necesaria y dar instrucciones precisas para preparar una receta, lavar ciertas fibras delicadas, o hacer pedidos de comestibles a su proveedor preferido en la Red. En HomeTech tambi?n se mostrar? otro tipo de electrodom?sticos asistidos por red, como hornos capaces de descargar autom?ticamente recetas y programas de cocci?n, dispositivos electr?nicos que permiten poner en marcha a distancia el lavavajillas, o equipos de aire acondicionado que se accionan mediante el uso del tel?fono y de Internet. <<<<< -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz From jcea at argo.es Tue Dec 18 23:08:30 2001 From: jcea at argo.es (Jesus Cea Avion) Date: Tue, 18 Dec 2001 23:08:30 +0100 Subject: [Domotica] Linksys Incorporates HomePlug Networking Message-ID: <3C1FBE5E.11E9C112@argo.es> http://slashdot.org/article.pl?sid=01/12/17/1829203 -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at argo.es http://www.argo.es/~jcea/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ _/_/_/_/_/ PGP Key Available at KeyServ _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz