Las clases de ingeniería electrónica suelen dictarse usando herramientas propietarias, así que siempre paso algunas horas buscando hacer mis trabajos con software libre. Por esta razón, he decidido compartir la siguiente guía. » pandacris | usemoslinux.blogspot.com
This project has been an astonishing little journey. Many of my previous projects were characterized by an amazing outpouring of effort to build something highly intricate and ultimately invisible. This is the opposite kind of project. A little bit of work and a little custom design to create something new and exciting that I can immediately use in my everyday life. It also happens to be a sex toy. In other words, I wanted to hack something I actually use: my vagina. ...
Paper Biped Robot making process from H/P MPM (Mechanical Paper Model) http://www.geocities.jp/kikousya290821/newmpm.htm All paper made Biped Robot without wooden shafts and elastic band as power source » geocities.jp/kikousya290821 | via microsiervos.com
Since 2004, I’ve owned a ThinkPad A22m - a laptop that came out in 2001. Much to the dismay of certain friends, I still feel no need to purchase a newer computer. I’ve often said that this old hardware can do everything I need while still letting me run modern software. However, it now seems like I will have to take some responsibility for the code if I want that to still be true in the future. Specifically, I am talking about open source ATI drivers on GNU / Linux. The four main video card lines released by ATI (now owned by AMD) have been Wonder, Mach, Rage and Radeon. I don’t think Wonder cards have any features that would warrant the development of a dedicated driver but Linux drivers for the other three have been written. The Radeon driver is actively maintained by software engineers at AMD and some people who work for other software companies. The other two? Not so much. The Rage 128 driver was especially in need of a major update recently. And since my computer has a Rage Mobility graphics card, I felt motivated to start working on the code even though I had never hacked such a low-level piece of software before. Since the effort has largely succeeded, I would like to share my experiences with editing an open source video driver. The learning curve was quite steep and when I first started reading documentation, it seemed like it was written for a different audience. This post is going to be an unadultered attempt to get a completely new reader to catch on to what I did. I’m sure I will later find out that many things written in this post are technically incorrect, but I will not edit them. I want the only knowledge communicated in this piece to be the knowledge that one might reasonably be expected to have after jumping into driver development for the first time. ...
Wi-Fi radio signals are found in 61 percent of homes in the U.S. and 25 percent worldwide, so Karl Woodbridge and Kevin Chetty, researchers at University College London, designed their detector to use these ubiquitous signals. When a radio wave reflects off a moving object, its frequency changes”a phenomenon called the Doppler effect. Their radar prototype identifies frequency changes to detect moving objects. It’s about the size of a suitcase and contains a radio receiver composed of two antennas ;íand a signal-processing unit. In tests, they have used it to determine a person’s location, speed and direction”even through a one-foot-thick brick wall. Because the device itself doesn’t emit any radio waves, it can’t be detected. ...
While transistors have many uses, one of the less known uses by amateurs is the ability for bipolar transistors to turn things on and off. While there are limitations as to what we can switch on and off, transistor switches offer lower cost and substantial reliability over conventional mechanical relays. In this article, we will review the basic principles for transistor switches using common bipolar transistors. The most commonly used transistor switch is the PNP variety shown in Figure 1. The secret to making a transistor switch work properly is to get the transistor in a saturation state. For this to happen we need to know the maximum load current for the device to be turned on and the minimum HFE of the transistor. ...
Arthur W. Burks / Herman H. Goldstine / John von Neumann PART I 1. Principal components of the machine 1.1. Inasmuch as the completed device will be a general-purpose computing machine it should contain certain main organs relating to arithmetic, memory-storage, control and connection with the human operator. It is intended that the machine be fully automatic in character, i.e. independent of the human operator after the computation starts. A fuller discussion of the implications of this remark will be given in Sec. 3 below. 1.2. It is evident that the machine must be capable of storing in some manner not only the digital information needed in a given computation such as boundary values, tables of functions (such as the equation of state of a fluid) and also the intermediate results of the computation (which may be wanted for varying lengths of time), but also the instructions which govern the actual routine to be performed on the numerical data. In a special-purpose machine these instructions are an integral part of the device and constitute a part of its design structure. For an all-purpose machine it must be possible to instruct the device to carry out any computation that can be formulated in numerical terms. Hence there must be some organ capable of storing these program orders. There must, moreover, be a unit which can understand these instructions and order their execution. ...
Using an Arduino and an 8x8 matrix display from Adafruit (with I2C backpack), we display all the solutions to the classic 8-Queens problem (see http://en.wikipedia.org/wiki/Eight_queens_puzzle ) A solution to the 8 Queen problem is where 8 queens are placed on a chess board so that no queen can take any other queen. » @stormingrobots | youtube.com
I’ve been wondering for some time whether the power consumption of an ATmega varies depending on the code it is running. Obviously, sleep modes and clock rate changes have a major impact – but how about plain loops? » jeelabs.org
As everyone knows, an important threat against the Internet is that of a coordinated DDoS attack against the root TLD DNS servers. The way I”d solve is with a simple inline device that both blocks some simple attacks from hitting the DNS server, but which can also answer simple queries, offloading the main server, even if it”s failed. This can be done with $2000, half for the desktop machine, and the other half for the dual-port 10-gig Ethernet. ...