Janet Louise Axelson | |
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Born | Janet Louise Axelson 1949 |
Nationality | America |
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Janet Louise Axelson (born 1949) is an American author and conservationist. She writes and publishes technical literature and documentation under the pen name Jan Axelson. [1] Much of her work relates to computer interfaces and protocols, including USB, Ethernet, serial, and parallel ports. Her books are published by her company Lakeview Research, LLC, which is based in Madison, Wisconsin. She has also written articles for Nuts and Volts, [2] and the Wisconsin State Journal. [3]
Axelson is the president of Friends of Cherokee Marsh, [4] [5] [6] a volunteer conservation organization based in Madison, Wisconsin that protects and restores the Cherokee Marsh wetland area, [7] an ecologically significant part of the Yahara River watershed. [8]
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a DTE such as a computer terminal or PC, and a DCE, such as a modem. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. The current version of the standard is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997. The RS-232 standard had been commonly used in computer serial ports and is still widely used in industrial communication devices.
Universal Serial Bus (USB) is an industry standard that allows data exchange and delivery of power between many types of electronics. It specifies its architecture, in particular its physical interface, and communication protocols for data transfer and power delivery to and from hosts, such as personal computers, to and from peripheral devices, e.g. displays, keyboards, and mass storage devices, and to and from intermediate hubs, which multiply the number of a host's ports.
A universal asynchronous receiver-transmitter is a peripheral device for asynchronous serial communication in which the data format and transmission speeds are configurable. It sends data bits one by one, from the least significant to the most significant, framed by start and stop bits so that precise timing is handled by the communication channel. The electric signaling levels are handled by a driver circuit external to the UART. Common signal levels are RS-232, RS-485, and raw TTL for short debugging links. Early teletypewriters used current loops.
A serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers.
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the electrical connectors, the frequencies to transmit on, the line code to use and similar low-level parameters, are specified by the physical layer.
COM is the original, yet still common, name of the serial port interface on PC-compatible computers. It can refer not only to physical ports, but also to emulated ports, such as ports created by Bluetooth or USB adapters.
AVR is a family of microcontrollers developed since 1996 by Atmel, acquired by Microchip Technology in 2016. These are modified Harvard architecture 8-bit RISC single-chip microcontrollers. AVR was one of the first microcontroller families to use on-chip flash memory for program storage, as opposed to one-time programmable ROM, EPROM, or EEPROM used by other microcontrollers at the time.
In computing, a parallel port is a type of interface found on early computers for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once, as opposed to serial communication, in which bits are sent one at a time. To do this, parallel ports require multiple data lines in their cables and port connectors and tend to be larger than contemporary serial ports, which only require one data line.
IEEE 488, also known as HP-IB and generically as GPIB, is a short-range digital communications 8-bit parallel multi-master interface bus specification developed by Hewlett-Packard. It subsequently became the subject of several standards.
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels.
In the context of installing firmware onto a device, a programmer, device programmer, chip programmer, device burner, or PROM writer is a device that writes, a.k.a. burns, firmware to a target device's non-volatile memory.
The ETRAX CRIS is a RISC ISA and series of CPUs designed and manufactured by Axis Communications for use in embedded systems since 1993. The name is an acronym of the chip's features: Ethernet, Token Ring, AXis - Code Reduced Instruction Set. Token Ring support has been taken out from the latest chips as it has become obsolete.
DisplayLink is a semiconductor and software technology company owned by Synaptics. The company specializes in developing DisplayLink USB graphics technology, which facilitates connections between computers and displays via USB, Ethernet, and WiFi. Additionally, it supports the connection of multiple displays to a single computer.
The SheevaPlug is a "plug computer" designed to allow standard computing features in as small a space as possible. It was a small embedded Linux ARM computer without a display which can be considered an early predecessor to the subsequent Raspberry Pi.
Active cables are copper cables used for data transmission that use an electronic circuit to boost their performance. Without an electronic circuit, a cable is considered passive. Passive cables are prone to data degradation from channel impairments, including attenuation, crosstalk, and group velocity distortion. In active cables, a circuit using one or several integrated circuits is embedded in the cable to compensate for some or all of these impairments. This active boosting allows cables to be more compact, thinner, longer, and to transmit data faster than passive cables.
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony and Panasonic. It is most commonly known by the name FireWire (Apple), though other brand names exist such as i.LINK (Sony), and Lynx.
HDBaseT is a consumer electronic (CE) and commercial connectivity standard for transmission of uncompressed ultra-high-definition video, digital audio, DC power, Ethernet, USB 2.0, and other control communication over a single category cable up to 100 m (328 ft) in length, terminated using 8P8C modular connectors. The conductors, cable, and connectors are as used in Ethernet networks, but are not otherwise exchangeable. HDBaseT technology is promoted and advanced by the HDBaseT Alliance.
STM32 is a family of 32-bit microcontroller integrated circuits by STMicroelectronics. The STM32 chips are grouped into related series that are based around the same 32-bit ARM processor core: Cortex-M0, Cortex-M0+, Cortex-M3, Cortex-M4, Cortex-M7, Cortex-M33. Internally, each microcontroller consists of ARM processor core(s), flash memory, static RAM, debugging interface, and various peripherals.
Intel Quark is a line of 32-bit x86 SoCs and microcontrollers by Intel, designed for small size and low power consumption, and targeted at new markets including wearable devices. The line was introduced at Intel Developer Forum in 2013, and discontinued in January 2019.
The MSP432 is a mixed-signal microcontroller family from Texas Instruments. It is based on a 32-bit ARM Cortex-M4F CPU, and extends their 16-bit MSP430 line, with a larger address space for code and data, and faster integer and floating point calculation than the MSP430. Like the MSP430, it has a number of built-in peripheral devices, and is designed for low power requirements. In 2021, TI confirmed that the MSP432 has been discontinued and "there will be no new MSP432 products".