In this video tutorial, we will control a pair of brushless motors from a Raspberry PI computer. We will use one of the computer's USB ports to connect a network of brushless motor controllers. We will power the computer, the controllers, and the brushless motors using a single battery, similar to a autonomous vehicle design.

The first motor is an outrunner type, a kind of what you would use for a vehicle propulsion. The bigger motor comes with a quadrature encoder which means it can be used as a powerful servo.

I made a cable to power my set up. On one end, the cable has a socket for plugging the battery. The cable splits into a two parallel parts to power the controllers, and the Raspberry PI. The bottom part of the cable further splits to power a pair of brushless motor controllers.
By the way, the controllers need 7 to 60 Volts DC. I put proper connectors at the ends of the cable, so that I could just plug it into the controllers.

Servosila brushless motor controllers come in rectangular or circular form factors. The controllers have USB and CANbus ports for connecting to control computers such as Raspberry PI.

The potential of VoIP to your customers is simply phenomenal. Businesses are experiencing the advantages of VoIP’s cost-efficiency and reliability and now you can pass these benefits onto your own customers very easily. Cloud telecommunication is sophisticated and easily integrated. Confidence in this technology is growing fast. There has never been a better time to start talking to your customers about adopting this solution. It will deliver huge business benefits for them and has the potential to increase business income and profitability.

Network architecture at hyperscalers is a subject to constant innovation and is ever evolving to meet the demand. Network operators are constantly experimenting with solutions and finding new ways to keep it reliable and cost effective. Hyperscalers are periodically publishing their findings and innovations in a variety of scientific and technical groups.

The purpose of this article is to summarize the information about how hyperscalers design and manage networks. The goal here is to help connecting the dots, dissect and digest the data from a variety of sources including my personal experience working with hyperscalers.

DISCLAIMER: All information in this article is acquired from public resources. This article contains my own opinion which might not match and does not represent the opinion of my employer.

Asymptotic notations are used to represent the complexity or running time of an algorithm. It is a technique of defining the upper and lower limits of the run-time performance of an algorithm.  We can analyze the runtime performance of an algorithm with the help of asymptotic notations. Asymptotic notations are also used to describe the approximate running time of an algorithm.

Types of Asymptotic Notations

Following are the different types of asymptotic notations:

Many of us spend time in specialized telegram groups. The power over communication here belongs to random people with their own shortcomings. Conflict and abuse occurs regularly. Is there another way to keep order so that scam spam doesn't flourish and no one has total control over group members?

In my case, these thoughts led to the development and testing of a system that can be connected to your Telegram today.

Introduction

It was 1989 when 2 editors of Inc. magazine, George Gendron and Bo Burlingham made the nervous drive to Palo Alto, California. Not long beforehand they’d decided on who to name as Inc.’s Entrepreneur of the Decade, and finally, they would get a chance to interview him.

As they entered the offices of NeXT, their interviewee approached them. In his trademark jeans and turtleneck sweater, Steve Jobs led them up the stairs to his office and the interview commenced.

Securing an interview with Steve Jobs was rare, even in 1989. And, wanting to make the most of their time, the editors got straight to the point with their very first question:

“Where do great products come from?”

After a slight pause, and a shuffle in his chair, Jobs replied:

“I think really great products come from melding two points of view; the technology point of view and the customer point of view. You need both. You can't just ask customers what they want and then try to give that to them. By the time you get it built, they'll want something new.”

Silence overshadowed the room. Three decades later, and this powerful answer Jobs gave is something that still isn’t often internalized in companies. 

Collecting user feedback is incredibly important. As you’ll see examples of later in this article, launching surveys, asking onboarding questions, and conducting customer interviews are all vital tools for improving your product. 

But the true lesson that Steve Jobs gave all this time ago was that user feedback isn’t as simple as asking what users want, or what they think about your product, and making those changes. You have to dive much deeper.

Enterprise policies are different, and in some cases weird. In this article, we will describe a very unusual problem raised by one of our customers. In a nutshell, the organization does not allow bringing any devices onsite, no smartphones, no mobile phones, and even no hardware tokens are allowed on-premises. At the same time, the organization is using Office 365 services from Microsoft and has enforced multi-factor authentication for all users to be activated.

To address this issue, our research and development team has spent some time and found a solution, which is a paper-based TOTP token. We are hereby presenting the solution, which is available for free (well, if you don't count the paper and ink cost).

Our solution is a web-based tool that generates the list of one-time passwords (OTPs) for an arbitrary seed. The list can be printed out and handed over to the end-users to serve as their second factor for authenticating in Azure AD with multi-factor authentication enabled. To associate this paper TOTP token with a user, you can follow the same procedure as with the regular TOTP tokens.

The procedure is simple, you enter the seed and click on submit to get the list generated. You will get a printable list similar to the one shown below for the next few days. By changing the number of future OTPs you can make the list longer or shorter.

The step has been made. Not sure where to, but for sure from the point of no return. Keep calm and keep walking. It is about time to look around and understand the smelly and slippery route before you. And what are those noisy creatures swarming around our fishy “innovative” design we called Mandelbrot blueprint? You don't get a buzzing noise like that, just buzzing and buzzing, without its meaning something.

Here I am going to cover my own approach to compilation of mathematical functions into Linq.Expression. What we are going to have implemented at the end:

1. Arithmetical operations, trigonometry, and other numerical functions

2. Boolean algebra (logic), less/greater and other operators

3. Arbitrary types as the function's input, output, and those intermediate

Hope it's going to be interesting!

Surely every C# developer has used out-parameters. It seems that everything is extremely simple and clear with them. But is it really so? For a kickoff, let's start with a self-test task.

You may have already read a recent article about the first PVS-Studio run and filtration of warnings. We used the GTK 4 project as an example. It's about time we worked with the received report in more detail. Our regular readers may have already guessed that this article will be a description of errors found in the code.

Hey Habr! I'm Ruslan, a Java programmer with experience in IT of 15 years who still doesn't understand how to grow as a technical specialist in a company.

Intro

So you are writing some CPU-intensive code in Python and really trying to find ways out of its single-threaded prison. You might be looking towards Numba's "nopython parallel" mode, you might be using forked processes with multiprocessing, you might be writing microservices with database-like coordinators, or even writing your own multithreaded programs in C/C++ just like creators of TensorFlow did.

In this article I'm describing a rationale for my pet project where I try to implement facilities for general purpose multitasking to be used in a form of simple python code, employing a database-like approach for interpreters communication, while keeping the GIL (Global Interpreter Lock) and trying to be as pythonic as possible.

It could also become handy in the light of upcoming multiple interpreters support in CPython.

As far as I know, nobody came that far in trying to provide Python program with native shareable storage. The last closest attempt was Python Object Sharing which is pretty much dead by now. I hope my project won't meet the same fate.

Introduction

Each game has data that game-designers work with. In RPG there is a database of items, in match-3 — the cost in the crystals of tools from the store, in action — hit points, for which medical kit heals.

There are many ways to store such data — someone stores it in tables, in XML or JSON files that edit with their own tools. Unity provides its own way — Scriptable Objects (SO), which I like because you don't have to write your own editor to visualize them, it's easy to make links to the game's assets and to each other, and with Addressables this data can be easily and conveniently stored off-game and updated separately.

In this article I would like to talk about my SODatabase library, with which you can conveniently create, edit and use in the game (edit and serialize) scriptable objects.

What is EVVIS-QR1?