My name is Serhii Pimenov. I’m a web developer from Kyiv, Ukraine (maybe you know me by the nickname olton).
Today I'm going to speak about one of my tools for the Mina blockchain - “Mina Monitor”. It’s the first article in the series about Mina and Mina Tools. In this article, I will introduce you to my tool for monitoring the Mina nodes.
In this video, we are making a cable for connecting a quadrature encoder to a Servosila brushless motor controller, and and then running a servo motor in Direct Drive mode. To make the cable we are using a cable assembly kit that can be purchased from the internet store. Alternatively, the components for the cable can be bought in other places. The part numbers are given in the controller's datasheet.
The cable assembly kit consists of a connector and a set of wires with pre-crimped socket blades. If you have a crimper tool, you can also attach the socket blades to wires by yourself.
Lets open a datasheet document that comes with the brushless motor controller. Note that each connector has its first pin clearly marked with a "1" sign. Conventionally, the numbering of pins is done in such a way that there are rows of odd-numbered and even-numbered pins.
The quadrature encoder's electrical interface has 5 wires in total. Positions of the pins of each of the wires are given in the table. The socket blades need to be pushed into the connector until you feel a "click". The blades lock into the connector's sockets. Optionally, primarily for cosmetic reasons, you may want to add a heat-shrink tubing to your cable.
The brushless motor controllers come in two distinct forms, a circular and a rectangular one. Both models are identical in terms of capabilities, features, firmware, and external electrical connectors.
The connector has a locking mechanism that keeps it in place. I soldered a mating connector to the other side of the cable - a connector that my brushless motor needs. Note that your motor will likely require a different connector, or no connector at all. It is always a good idea to test an end-to-end integrity of the cable and its connectors. Lets buzz the wires using a multimeter. The cable is ready.
SEPIC-Ćuk split-rail converter can be used to make positive and negative supplies from a single input voltage for relatively well-matched loads like operational amplifiers.
Transient models are time consuming. Average models reduce modeling time drastically.
The PWM switch average models for current- and voltage-mode are described in details in Christophe Basso’s book “Switch-Mode Power Supplies, Second Edition: SPICE Simulations and Practical Designs”. Using of these models for SEPIC and Ćuk converters is also shown.
This text shows how to use the PWM switch average model to design a split-rail SEPIC-Ćuk converter.
Free money to fund your own business is probably the most cherished dream of every budding entrepreneur.
And getting a grant is what can bring it to life. While small business owners dream of a grant to fund their startup, the process of its obtaining is not as easy and cloudless as it may seem.
However, if you know where to look for the right fund and how to apply, one can significantly nick in the path to getting seed money.
Difference between a grant, attracted investment, and loan.
Nothing and nobody will escape oblivion. Whatever you may say, the history of mankind is a history of automation and the subsequent evolution of workers. This happened both during the first industrial revolution and during the second. The same thing happened with digital revolution. Now machine learning and artificial intelligence are being implemented everywhere. What is the future of software testing?
Hi from RaccoonLab, a team of enthusiasts in field robotics! We want to share our true-HITL UAVCAN-based simulator for PX4.
We believe a unified UAVCAN bus for drone onboard electronics will become a mainstream approach shortly. Our simulator is already based on UAVCAN (in opposition to UART-MAVLINK) and emulates exactly the same messages as real UAVCAN-sensors.
November 10, 2020 was in many ways a landmark event in the microprocessor industry: Apple unveiled its new Mac Mini, the main feature of which was the new M1 chip, developed in-house. It is not an exaggeration to say that this processor is a landmark achievement for the ARM ecosystem: finally an ARM architecture chip whose performance surpassed x86 architecture chips from competitors such as Intel, a niche that had been dominated for decades.
But the main interest for us is not the M1 processor itself, but the Rosetta 2 binary translation technology. This allows the user to run legacy x86 software that has not been migrated to the ARM architecture. Apple has a lot of experience in developing binary translation solutions and is a recognized leader in this area. The first version of the Rosetta binary translator appeared in 2006 were it aided Apple in the transition from PowerPC to x86 architecture. Although this time platforms were different from those of 2006, it was obvious that all the experience that Apple engineers had accumulated over the years, was not lost, but used to develop the next version - Rosetta 2.
We were keen to compare this new solution from Apple, a similar product Huawei ExaGear (with its lineage from Eltechs ExaGear) developed by our team. At the same time, we evaluated the performance of binary translation from x86 to Arm provided by Microsoft (part of MS Windows 10 for Arm devices) on the Huawei MateBook E laptop. At present, these are the only other x86 to Arm binary translation solution that we are aware of on the open market.
Knowing parameters of small-signal control-to-output transfer functions makes it easier for engineers to design compensation networks of DC/DC converters. The equations for SEPIC can be found in different works and Application Notes, but there are differences. A work has been done to solve this problem.
Simplified design equations for SEPIC with Current Mode control (CM) in Continuous Conduction Mode (CCM) suitable for practical design of compensation networks are shown.
The The Open Network (TON) is a fast, secure and scalable blockchain and network project, capable of handling millions of transactions per second.
It was originally introduced by Telegram and called Telegram Open Network. Unfortunately, in May 2020, they announced the closure of the project due to the US court decision. Right after that, three different organizations announced their intentions to continue work on the blockchain: TON Labs, NewTON (TON Foundation), and the Chinese TON community.
In early August, the Telegram team transferred the original repository on GitHub, as well as the ton.org domain, to the open developer community of the TON Foundation.
You can read more about it here.
In this tutorial, you will learn how to set up & run a TON validator using mytonctrl on Ubuntu. Note that, it is only dedicated to validators on the NewTON (TON Foundation) blockchain.
Hello, Habr! Not only traders but also mathematicians and programmers work with stock markets. Director of Engineering at Luxoft Artem Sosulnikov tells about data, which specialists of quantitative hedge funds work with, things they pay attention to, and conditions in such companies.
In this video, we will look at how to connect brushless motor controllers to a Linux computer. Specifically, we will use a computer running Debian. The same steps would work for Ubuntu Linux and other Linux distributions derived from Debian.
I've got a small sensorless brushless motor, and a bigger brushless motor with a built-in absolute encoder. Lets look at how to control those from my Debian Linux computer. Servosila brushless motor controllers come in several form factors with either a circular or a rectangular shape. The controllers come with a set of connectors for motors and encoders as well as for USB or CANbus networks.
The controllers can be powered by a power supply unit or by a battery. To spice up my setup, I am going to use a battery to power the controllers and thus their motors. The controllers need 7 to 60 volts DC of voltage input. If I connect the battery, the controllers get powered up. The small LED lights tells us that the controllers are happy with the power supply.
We need to connect the brushless motor controllers to the Linux computer. There are two ways to do that - via CANbus or via USB. Lets look at the USB option first. A regular USB cable is used. Only one of the controllers needs to be connected to a computer or a PLC.
Next, we need to build an internal CANbus network between the controllers. We are going to use a CANbus cross-cable to interconnect the controllers. Each controller comes with two identical CANbus ports that help chain multiple controllers together in a network. If one of the interconnected brushless motor controllers is connected to a computer via USB, then that particular controller becomes a USB-to-CANbus gateway for the rest of the network. Up to 16 controllers can be connected this way via a single USB cable to the same control computer or a PLC. The limit is due to finite throughput of the USB interface.
In this video, we will look at how to connect brushless motors to a Windows computer via USB. We are going to connect a network of Servosila brushless motor controllers to the computer. The other option is CANbus interface, but we will look at CANbus in a dedicated video. A regular USB cable is used. Note that the USB cable is not used to power the controller and its motor.
The first brushless motor controller in network appears to Windows as a Virtual COM port. Once connected via USB, it can be found in a general list of devices in the Window's "Settings" window. Up to 16 controllers can be connected this way via a single USB cable to the same control computer or a PLC. If one of the interconnected brushless motor controllers is connected to a computer via USB, then that particular controller becomes a USB-to-CANbus gateway for the rest of the network.
If your computer happens to have more that one serial port, you may wish to check a COM port's number assigned by Windows to the controller. Then, you pick this COM port in a drop down menu in the Servoscope software, and click Connect. If the COM port is not listed in the drop-down menu, click the Refresh button. If everything is good, the controller appears in a list of devices. Double-click to open up a control and configuration window.
As already described in the previous article, in the process of reworking the DSO138 oscilloscope toy, the idea arose in the DSO303 firmware at some point to try to double the maximum sampling frequency to achieve scanning times of 500 and 200 nanoseconds per cell. In fact, for the STM32F303, the theoretically maximum achievable sampling rate from the point of view of the ADC input, and this is determined by the minimum opening time of the ADC sampling unit, which in our case is 1.5 clock cycles x (1/72 MHz) = 20.8 nanoseconds, is 48 MSPS (millions of counts per second). However, with the parallel operation of 4 ADCs at 6 MHz, it is possible to achieve only 24 MSPS due to the limited speed of the ADC.
Let's imagine that we are considering correctly-periodic signal, which is also constant, i.e. it does not experience fluctuations in frequency and amplitude over time. Is it possible to somehow digitize it not in one, but in several passes, thereby increasing the effective sampling frequency?
On Ali, an interesting toy – an oscilloscope called DSO138 is sold for a very inexpensive price. It has already gained quite a lot of popularity among electronics lovers, but the parameters of this device, alas, allow it to be more or less fully used only for debugging very low-frequency circuits. Actually, it is not positioned as a tool, but rather as a DIY-kit for novice electronics engineers.
This "toy" oscilloscope is assembled on the STM32F103 microcontroller, and with a fairly competent circuit design of the digital part, the presence of a fairly decent 320X240-dot color display, and not the most rotten analog path, everything, alas, is ruined by very weak ADCs on board the 32F103. The claimed band of 200 kHz can be recognized as such only with a very large stretch. Yes, it will show the presence or absence of a signal with such a frequency, but it will not be possible to really look at something beyond this.
At the same time, the 103-series has a slightly more powerful brother - the STM32F303, it is almost completely compatible with the legs, but it is significantly better in terms of the parameters we are interested in, there are 4 ADCs on board with a conversion frequency of 5 MHz (6 MHz with a 10-bit resolution). In this scenario, if you use all 4 ADCs in parallel with a 10-bit resolution, you can get a effective resolution of up to an honest 24 MSPS (millions of samples per second). The microcontroller is also inexpensive; you can easily find it on the same Ali for very reasonable money again. It is clear that the idea to change the microcontroller arose almost immediately after I tried this DSO138.
At the same time, if upgraded the toy can turn out to be a completely full-fledged tool that even professionals, not just novice amateurs, could already use. With these thoughts in mind, I decided to try to do something with a Chinese toy in my free time.
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.
In the comment sections of our articles about our server there are often users who say: "Why would you jump through so many hoops, when you can do the same with a single line of code in FFmpeg!?"
RAM disk, this is a disk based on RAM memory chips. This kind of disk is not able to retain data after the power is turned off (unless a supporting battery is used), but has an exceptionally high read/write speed (especially for random access) and an unlimited lifespan. It is important in tasks that need a lot of cycles to write over information, even professional SSD drives don’t live long. To the operating system the RAM disk is indistinguishable from an SSD or HDD disk and no special drivers or setup is required. Unlike a disk that is virtually located in the computer’s RAM memory, where the maximum memory capacity is limited to 128-256 GB in the best consumer motherboards, a RAM disk for a PCIe slot, in general, has no volume limits and can work in any MB with a PCIe slot.