• Koyaanisqatsi: The WYSIWYG-style byte-code CPU

      Draft diagram of core

      SVG-File (actual draft)

      Lyrics


      Ancient times are known to everyone not with immortal works from Homer's only, but also with the Pythagorean multiplication table, Euclidean geometry and the Archimedes screw and the Pi, which we learned to use only relatively recently. In antiquity the art was not only to be able to write poetry and prose, but to design catapults or battering tools also, now there are rigid frameworks, when the discovering the new another beautiful formula is a formal words play only.
      Mathematics rules the modern world completely, cynically intertwining with the world of art, intruding with calculations in all spheres of our recreation and everyday life, when the colors of masterpieces turning into poisonous colours.
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    • How I create browser applications inside browsers

      • Translation

      GitJS


      In 2013 Canonical tried to crowdfund Ubuntu Edge smartphone. Its main feature could be the ability to use the smartphone as a full-fledged PС. Unfortunatly, the crowdfunding campaign did not accumulate enough money, so a dream of having a universal device remained to be the dream.


      I've been searching for universality, too, on the software side, not the hardware one. Today I can confidently say I found the necessary combination: Git and JavaScript.


      As you know, I have already described the benefits of browser applications (nCKOB static site generator) and the benefits of using Git instead of yet another back-end with API (GitBudget to track personal spendings). Once GitBudget was out, I spent the remaining 2020 to build a system allowing one to create browser applications right inside browsers. GitJS is the name of that system.

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    • Robotic Floor Washer

      • Tutorial

      When we think about robots, the first thing that comes to mind are robotic vacuum cleaners. The reason is simple: they are the most "solid" demonstration of success of "consumer" robotics. So making one sounds like a good idea... at first.

      But isn't it a bit counter productive - to build something that popular, something we can buy in a store at a commodity (small) price? Should we build something similar, but NOT a vacuum cleaner? Something like... a floor washer, perhaps? Yes, a robotic floor washer.

      In this tutorial I am going to build a fully working prototype of a robotic floor washer. By "fully working" I mean that it is going to wash floor, instead of moving dirt around like most robotic "moppers" do. While by "prototype" I mean it is going to be the first step towards production-ready unit, but not a production-ready unit yet. Let me explain.

      First of all, it is not going to be THAT solid. You can grab a robotic vacuum cleaner that you got from the store by any part, including wheels and bumper and lift it. It will not fall apart. Ours probably will. The reason is, to make a device "mechanically solid" is a separate task, and if we focus on it, then "robotic" tasks will become more difficult to achieve. So we are going to do what engineers usually do: first they build C3PO without the outside body, wires everywhere and so on. And only then they put a gold-covered outfit on it.

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    • Active Termination Drivers

      • Tutorial


      The easiest way to build a driver with specified output impedance is to use an amplifier with high load compatibility and add a resistor to its output. The penalty is voltage drop across this resistor, so there is power loss and we need a higher supply voltage. If our driver is able to deliver the same voltage and current to the same load, but the extra resistor will have a lower value, our device will be able to deliver the same output power at a lower supply voltage. Less power losses, less heat, and longer working time when a battery is used.
      There is an idea how to solve this problem: active termination. We can synthesize the output impedance!

      Now when we know what we want, go to design our drivers!
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    • Compensation for Error Caused by Limited Gain-Bandwidth of Operational Amplifiers in Low-pass Filters

      • Tutorial
      Amateur vs Pro

      An operational amplifier has the internal compensation circuit for stability which limits its working bandwidth. Frequency response of the compensated Op Amp has slope of −6 dB/octave or −20 dB/decade. Unity gain frequency defines the bandwidth where the Op Amp is able to amplify a signal. If we multiply the gain and frequency at any point, the result is the same, allowing us to use this parameter to select the appropriate Op Amp. It is called Gain-Bandwidth Product, GBW or GBP. The limited open-loop gain introduces a closed-loop gain and phase error.

      But we want to optimize our circuits, right?
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    • Ads
      AdBlock has stolen the banner, but banners are not teeth — they will be back

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    • How to verify Switching-Mode Power Supply circuits

      It is always good practice to verify a circuit before using.

      Switching-Mode Power Supplies are the most used circuits nowadays. But there are some difficulties with verifying their circuits: vendors do not publish models for all controllers; a model can be locked to be used with some tool; there can be errors in a model; average models want correct parameters and you need some practice of using them; transient models take a lot of time to get small-signal response and also can have errors.

      Let’s try to verify one circuit using my favorite electronics design tool “Circuit Calculator”.
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    • How to save energy with BARY: Smart Home

      • Translation


      Well, every modern person has at least once wondered: for how much longer can you pay such huge utility bills?! I am no exception. Electricity, gas, heating, water, rent, elevator, removal of solid waste, etc. etc.

      One of the reasons (far from the last) of creating the BARY application was the ability to collect statistics, analyze and reduce energy consumption. Europe has long passed into the regime of total economy; I think this fate will not bypass us. Therefore, to prepare for this in advance definitely will not be superfluous.

      I now propose that we examine how we managed to optimize the cost of electricity along with BARY: Smart Home.
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    • How to make your home ‘smart’ without going crazy

      • Translation
      image

      Smart furniture, which keeps your house in order, is a must for almost any futuristic set. In fact, an auto-regulating climate, automatic lights and voice control over household devices — all this can be done and configured now. But it will take a little experience, basic knowledge of technology and sometimes programming, as well as a whole sea of ​​fantasy. In my case, I did in the way that just fantasy will be enough, but first things first…
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    • Как с помощью HUAWEI ML Kit самостоятельно создать апплет для фото на документы

        Общая информация


        В предыдущей статье мы рассказали о том, как создать камеру для улыбок с помощью HUAWEI ML Kit. В этот раз я собираюсь представить вам новую функцию HUAWEI ML Kit.

        Вас когда-нибудь просили на учебе или работе принести фотографию определенного размера с цветным фоном для документов? В большинстве случаев у человека не окажется под рукой подходящей фотографии. Однажды в институте нам решили оформить персональные пропуска, но фотостудия оказалась закрыта. Тогда я сфотографировался на телефон, использовав простыню в качестве фона. И получил выговор от преподавателя. Но с помощью инструмента HUAWEI ML Kit вы сможете интегрировать SDK для сегментации изображений в ваше приложение и разработать апплет, чтобы создавать фото на документы самостоятельно и решить проблему отсутствия нужных фотографий.

        Самое главное, что этот SDK абсолютно бесплатный и работает на всех телефонах на базе Android.

        Разработка апплета для фото на документы самостоятельно


        1. Подготовка


        1.1 Добавьте репозиторий Maven Huawei в файл на уровне проекта build.gradle


        Откройте файл build.gradle в корневом каталоге вашего проекта Android Studio.

        image

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      • Why I keep track of spendings in a personal app made with Git+JS

        • Translation

        Hi, folks, let me share my experience of creating an application to keep track of my spendings. Specifically, let me do it by answering the following questions:


        1. Why keep track of spendings in an application?
        2. Why did I create the application as a personal project?
        3. Why does the project use Git+JS?

        1. Why keep track of spendings in an application?


        I, like many people out there, wanted to become rich and successful. To become rich, one is often advised to run a personal budget, that's what I started to do several years ago. I'd like to point out that running my personal budget hasn't made me rich and successful, and I increased income simply by moving to Moscow.

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      • The snail terrarium concept

        • Translation
        Hello everybody! Today I want to share with you the concept of a rather unusual device, which, like the alarm remote for the "ZAZ Zaporozhets", was developed exclusively for creative purposes, without the further implementation.



        It all started with the fact that two of the three grape snails escaped from our director's terrarium, and the third one died suddenly without lasting even three days. Obviously, the blame for this situation was putted not on the inability to keep the mollusk and irresponsibility, but on the “terrible terrarium”.
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      • Using Data Science for house hunting in Montreal

          Introduction


          I happen to live in Montreal, in my condo on the edge of McGill Ghetto. Close to Saint Laurent Boulevard or the Maine as locals call it, with all it's attractions — bars, restaurants, night clubs, drunken students. And once upon a time, on a particular lively night, listening to the sounds of McGill frosh students drunkenly heading home after hard night of studying. I thought, that it might be a good idea to move into my own house, a little bit further away from the action.


          Image

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        • Teaching folks to program 2019, a.k.a. in the search of an ideal program: Sequence

          • Translation

          MUROM


          Hi, my name is Michael Kapelko. I'm a professional software developer. I'm fond of developing games and teaching folks to program.


          Preface


          Autumn 2019 was the third time I participated as one of the teachers in the course to teach 10-15-year-old folks to program. The course took place from mid. September to mid. December. Each Saturday, we were studying from 10 AM to 12 PM. More details about the structure of each class and the game itself can be found in the 2018 article.


          I have the following goals for conducting such courses:


          • create a convenient tool to allow the creation of simple games, the tool interested folks of 10 years old or older can master;
          • create a program to teach programming, the program interested folks of 10 years old or older can use themselves to create simple games.
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        • Hypercube. How we gave developers test devices without losing any

            You can’t properly test and debug mobile apps without test devices, which there should be plenty of considering how the same code may behave differently on different models. So how do we keep track of these devices? How do we quickly provide developers and testers with the smartphones they need, configured the way they need, and without much red tape?

            I’m Alexey Lavrenuke. Over the years, I’ve worn many hats: one of the authors behind Yandex.Tank, a speaker on load testing, and the guy who calculated energy consumption by mobile phones. Now I’m a Yandex.Rover developer on the self-driving car team.

            After the phones and before Yandex.Rover, there was Hypercube.

            A few years ago, the head of mobile development popped in to the load testing department and mentioned a problem they were having with test devices: phones had a tendency to inexplicably migrate from one desk to another. Picking the right device and then finding it had become a challenge. We already experienced working with mobile devices from building a digital ammeter to calculate energy consumption, so we decided to help our coworkers out and quickly rig up a handy contraption. We figured the whole thing wouldn’t take more than three months. Oh how wrong we were. Let me tell you what we were really in for.


            ''Dallas cube''
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          • Tesla Cybertruck copy was spotted in Moscow. This is a customized… Russian LADA Samara

              image

              Hi Habr! Just noticed that this funny article exists only in Russian, so I’ve decided to translate it to English with some light modifications. Please enjoy!

              Few days ago Tesla Cybertruck replica has been spotted on the roads of Moscow. The design of the electric pickup presented by Elon Musk can't be confused with anything else.
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            • Reverse engineering a high-end soldering station



                (This is the translation of the original article performed by baragol)

                We had a bunch of photographs of the main PCB, a YouTube video with drain-voltage waveforms of MOSFETs, a forum post with a breakdown of the capacitance values of LC circuit capacitors and also a number of unboxing videos showing the heating-up of the soldering tip. The only thing that really worried me was the video with the measurement of the peak power consumption during the heating-up. There is nothing in the world more helpless and irresponsible and depraved than burned cartridge newly bought for 60 bucks from Amazon. But let me start from the beginning.
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              • Board game for learning the basics of electrical circuits. Why not?


                  I made the “electric” designer of… cardboard. Alas, the project still remains at the prototype stage, not developing into an industrial “physical” look and is waiting for its time (and investor).


                  But I decided to go further — once we started making cardboard, we’ll bring the situation to its logical conclusion — we’ll make a complete cardboard board game, but with an electric setting and a learning effect. There were a lot of options — starting from a simple “walker” and ending with Ameritrash from a zombie with electron movement and vicious short circuits and swollen capacitors.


                  As a result, I decided to dwell on a logical abstract, since the schematics of electrical circuits are very suitable for it. Said and done — as a result of the first iteration, the game “Circuit” was born.

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                • We're in UltraHD Morty! How to watch any movie in 4K

                    You’ve probably heard about Yandex’s DeepHD technology they once used to improve the quality of old Soviet cartoons. Unfortunately, it’s not public yet, and we, regular programmers, don’t have the dedication to write our own solution. But I personally really wanted to watch Rick and Morty on my 2880x1880 Retina display. And I was deeply disappointed, as even 1080p video (the highest available for this series) looks really blurry on a Retina display! Don’t get me wrong, 1080p is often good enough, but Retina is designed in such a way that an animation with its pronounced outlines in 1080p looks awfully blurry, like 480p on a FullHD monitor.

                    I decided I want to see Rick and Morty in 4K, even though I can’t write neural networks. And, amazingly, I found a solution. You don’t even need to write any code: all you need is around 100GB of free space and a bit of patience. The result is a sharp 4K image that looks better than any interpolation.


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