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Apache Mynewt
Apache Mynewt is a modular real-time operating system for connected Internet of things (IoT) devices that must operate for long times under power, memory, and storage constraints. It is free and open-source software incubating under the Apache Software Foundation, with source code distributed under the Apache License 2.0, a permissive license that is conducive to commercial adoption of open-source software. Overview Apache Mynewt is a real-time operating system with a rich set of libraries intended to make prototyping, deploying, and managing 32-bit microcontroller based IoT devices easy. It is highly composable, to allow building embedded system applications (e.g., locks, medical devices, industrial IoT) across different types of microcontrollers. The name ''Mynewt'' is wordplay on the English word ''minute'', meaning very small: the kernel is only 6 KB in size. The OS is designed for connectivity, and comes with a full implementation of the Bluetooth low energy 4.2 stack. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Apache Mynewt Logo
The Apache ( ) are several Southern Athabaskan language-speaking peoples of the Southwest, the Southern Plains and Northern Mexico. They are linguistically related to the Navajo. They migrated from the Athabascan homelands in the north into the Southwest between 1000 and 1500 CE. Apache bands include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Salinero, Plains, and Western Apache ( Aravaipa, Pinaleño, Coyotero, and Tonto). Today, Apache tribes and reservations are headquartered in Arizona, New Mexico, Texas, and Oklahoma, while in Mexico the Apache are settled in Sonora, Chihuahua, Coahuila and areas of Tamaulipas. Each tribe is politically autonomous. Historically, the Apache homelands have consisted of high mountains, sheltered and watered valleys, deep canyons, deserts, and the southern Great Plains, including areas in what is now Eastern Arizona, Northern Mexico (Sonora and Chihuahua) and New Mexico, West Texas, and Southern Colorado. These areas are c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Apache License
The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software under the terms of the license, without concern for royalties. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects. History Beginning in 1995, the Apache Group (later the Apache Software Foundation) released successive versions of the Apache HTTP Server. Its initial license was essentially the same as the original 4-clause BSD license, with only the names of the organizations changed, and with an additional clause forbidding derivative works from bearing the Apache name. In July 1999, the Berkeley Software Distribution accepted the argument put to it by the Free Software Foundation and retired their ''advertising clause'' (clause 3) to form the new 3-clau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mutex
In computer science, a lock or mutex (from mutual exclusion) is a synchronization primitive that prevents state from being modified or accessed by multiple threads of execution at once. Locks enforce mutual exclusion concurrency control policies, and with a variety of possible methods there exist multiple unique implementations for different applications. Types Generally, locks are ''advisory locks'', where each thread cooperates by acquiring the lock before accessing the corresponding data. Some systems also implement ''mandatory locks'', where attempting unauthorized access to a locked resource will force an exception in the entity attempting to make the access. The simplest type of lock is a binary semaphore. It provides exclusive access to the locked data. Other schemes also provide shared access for reading data. Other widely implemented access modes are exclusive, intend-to-exclude and intend-to-upgrade. Another way to classify locks is by what happens when the lock stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type used to control access to a common resource by multiple threads and avoid critical section problems in a concurrent system such as a multitasking operating system. Semaphores are a type of synchronization primitive. A trivial semaphore is a plain variable that is changed (for example, incremented or decremented, or toggled) depending on programmer-defined conditions. A useful way to think of a semaphore as used in a real-world system is as a record of how many units of a particular resource are available, coupled with operations to adjust that record ''safely'' (i.e., to avoid race conditions) as units are acquired or become free, and, if necessary, wait until a unit of the resource becomes available. Though semaphores are useful for preventing race conditions, they do not guarantee their absence. Semaphores that allow an arbitrary resource count are called counting semaphores, while semaphores that are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Programmable Interval Timer
In computing and in embedded systems, a programmable interval timer (PIT) is a counter that generates an output signal when it reaches a programmed count. The output signal may trigger an interrupt. Common features PITs may be one-shot or periodic. One-shot timers will signal only once and then stop counting. Periodic timers signal every time they reach a specific value and then restart, thus producing a signal at periodic intervals. Periodic timers are typically used to invoke activities that must be performed at regular intervals. Counters are usually programmed with fixed intervals that determine how long the counter will count before it will output a signal. IBM PC compatible The Intel 8253 PIT was the original timing device used on IBM PC compatibles. It used a 1.193182 MHz clock signal (one third of the color burst frequency used by NTSC, one twelfth of the system clock crystal oscillator, therefore one quarter of the 4.77 MHz CPU clock) and contains three timers. Timer 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Scheduling (computing)
In computing, scheduling is the action of assigning resources to perform tasks. The resources may be processors, network links or expansion cards. The tasks may be threads, processes or data flows. The scheduling activity is carried out by a mechanism called a scheduler. Schedulers are often designed so as to keep all computer resources busy (as in load balancing), allow multiple users to share system resources effectively, or to achieve a target quality-of-service. Scheduling is fundamental to computation itself, and an intrinsic part of the execution model of a computer system; the concept of scheduling makes it possible to have computer multitasking with a single central processing unit (CPU). Goals A scheduler may aim at one or more goals, for example: * maximizing '' throughput'' (the total amount of work completed per time unit); * minimizing '' wait time'' (time from work becoming ready until the first point it begins execution); * minimizing '' latency'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Thread (computer Science)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. The implementation of threads and processes differs between operating systems. History Threads made an early appearance under the name of "tasks" in IBM's batch processing operating system, OS/360, in 1967. It provided users with three available configurations of the OS/360 control system, of which Multiprogramming with a Variable Number of Tasks (MVT) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
ChibiOS/RT
ChibiOS/RT is a compact and fast real-time operating system for microcontrollers supporting multiple architectures and released under a mix of the GNU General Public License version 3 (GPL3) and the Apache License 2.0 (depending on module). It is developed by Giovanni Di Sirio. Commercial licenses are available from ''ChibiOS''. Additional products include ChibiOS/HAL, a hardware abstraction layer compatible with ChibiOS/RT, and ChibiStudio, a free integrated development environment based on Eclipse, the GNU Compiler Collection, and the OpenOCD Joint Test Action Group (JTAG) debugging pod. Metrics ChibiOS/RT is designed for embedded applications on microcontrollers of 8-, 16-, and 32-bits. Size and execution efficiency are the main project goals. As reference, the kernel size can range from a minimum of 1.2 KiB up to a maximum of 5.5 KiB with all the subsystems activated on a STM32 Cortex-M3 processor. The kernel can achieve over 220,000 created/terminated threads p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Boot Loader
A bootloader, also spelled as boot loader or called bootstrap loader, is a computer program that is responsible for booting a computer and booting an operating system. If it also provides an interactive menu with multiple boot choices then it's often called a boot manager. When a computer is turned off, its softwareincluding operating systems, application code, and dataremains stored on non-volatile memory. When the computer is powered on, it typically does not have an operating system or its loader in random-access memory (RAM). The computer first executes a relatively small program stored in the boot ROM, which is read-only memory (ROM, and later EEPROM, Flash memory#NOR flash, NOR flash) along with some needed data, to initialize hardware devices such as CPU, motherboard, memory, storage and other I/O devices, to access the nonvolatile device (usually Device file#Block devices, block device, e.g., NAND flash) or devices from which the operating system programs and data can be l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bluetooth Low Energy
Bluetooth Low Energy (Bluetooth LE, colloquially BLE, formerly marketed as Bluetooth Smart) is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group (Bluetooth SIG) aimed at novel applications in the healthcare, fitness, beacons, security, and home entertainment industries. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range. It is independent of classic Bluetooth and has no compatibility, but Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and LE can coexist. The original specification was developed by Nokia in 2006 under the name Wibree, which was integrated into Bluetooth 4.0 in December 2009 as Bluetooth Low Energy. Mobile operating systems including iOS, Android, Windows Phone and BlackBerry, as well as macOS, Linux, Windows 8, Windows 10 and Windows 11, natively support Bluetooth Low Energy. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Minute
A minute is a unit of time defined as equal to 60 seconds. It is not a unit in the International System of Units (SI), but is accepted for use with SI. The SI symbol for minutes is min (without a dot). The prime symbol is also sometimes used informally to denote minutes. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds; there is also a provision to insert a negative leap second, which would result in a 59-second minute, but this has never happened in more than 40 years under this system. History Al-Biruni first subdivided the hour sexagesimally into minutes, seconds, thirds and fourths in 1000 CE while discussing Jewish months. Historically, the word "minute" comes from the Latin ''pars minuta prima'', meaning "first small part". This division of the hour can be further refined with a "second small part" (Latin: ''pars minuta secunda''), and this is where the word "second" comes from. For even further refinement, the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Embedded System
An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. , it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems. Modern embedded systems are often based on microcontrollers (i.e. microprocessors with integrated memory and peripheral interfaces), but ordinary microprocessors (using external chips for memory and peripheral interface circuits) are also common, especially in more complex systems. In either case, the processor(s) us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
