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N900
The Nokia N900 is a smartphone made by Nokia, launched at Nokia World on 2 September 2009 and released in November. Superseding the Nokia N810, the N900's default operating system, Maemo 5, is a Linux-based OS originally developed for the Nokia 770 Internet Tablet. It is the first Nokia device based upon the Texas Instruments OMAP3 microprocessor with the ARM Cortex-A8 core. Unlike the three Nokia Internet tablets preceding it, the Nokia N900 is the first Maemo device to include telephony functionality ( quad-band GSM and 3G UMTS/HSDPA). The N900 functions as a mobile Internet device, and includes email, web browsing and access to online services, a 5-megapixel digital camera for still or video photography, a portable media player for music and video, calculator, games console and word processor, SMS, as well as mobile telephony using either a mobile network or VoIP via Internet (mobile or Wi-Fi). Maemo provides an X-terminal interface for interacting with the core opera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nokia N900
The Nokia N900 is a smartphone made by Nokia, launched at Nokia World on 2 September 2009 and released in November. Superseding the Nokia N810, the N900's default operating system, Maemo 5, is a Linux-based OS originally developed for the Nokia 770 Internet Tablet. It is the first Nokia device based upon the Texas Instruments OMAP#OMAP 3, Texas Instruments OMAP3 microprocessor with the ARM Cortex-A8 core. Unlike the three Nokia Internet tablets preceding it, the Nokia N900 is the first Maemo device to include Cellular network, telephony functionality (quad-band GSM and 3G UMTS/HSDPA). The N900 functions as a mobile Internet device, and includes email, web browsing and access to online services, a 5-megapixel digital camera for still or video photography, a portable media player for music and video, calculator, games console and word processor, SMS, as well as mobile telephony using either a mobile network or VoIP via Internet (mobile or Wi-Fi). Maemo provides an X terminal, X-te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maemo
Maemo is a Linux-based software platform originally developed by Nokia, now developed by the Free software movement, community, for smartphones and Internet tablets. The platform comprises both the Maemo operating system and Software development kit, SDK. Maemo played a key role in Nokia's failed strategy to compete with Apple Inc., Apple and Android (operating system), Android; the only retail devices that shipped with Maemo were the Nokia Internet tablet line released in 2005 and the Nokia N900 smartphone in 2009. Maemo is mostly based on Free and open-source software, open-source code and has been developed by Maemo Devices within Nokia in collaboration with many open-source projects such as the Linux kernel, Debian, and GNOME. Maemo is based on Debian and draws much of its GUI, software framework, frameworks, and library (computing), libraries from the GNOME project. It uses the Matchbox (window manager), Matchbox window manager and the GTK-based Hildon framework as its GUI a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas Instruments OMAP
OMAP (Open Multimedia Applications Platform) is a family of image processor, image/video processors that was developed by Texas Instruments. They are proprietary system on chips (SoCs) for portable and mobile multimedia application software, applications. OMAP devices generally include a general-purpose ARM architecture processor core plus one or more specialized co-processors. Earlier OMAP variants commonly featured a variant of the Texas Instruments TMS320 series digital signal processor. The platform was created after December 12, 2002, as STMicroelectronics and Texas Instruments jointly announced an initiative for ''Open Mobile Application Processor Interfaces'' (OMAPI) intended to be used with 2G#2.5G (GPRS), 2.5 and 3G mobile phones, that were going to be produced during 2003. (This was later merged into a larger initiative and renamed the MIPI Alliance.) The OMAP was Texas Instruments' implementation of this standard. (The STMicroelectronics implementation was named Nomad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PowerVR
PowerVR is a division of Imagination Technologies (formerly VideoLogic) that develops hardware and software for 2D and 3D rendering, and for video encoding, video decoding, decoding, associated image processing and DirectX, OpenGL ES, OpenVG, and OpenCL acceleration. PowerVR also develops AI accelerators called Neural Network Accelerator (NNA). The PowerVR product line was originally introduced to compete in the desktop PC market for Graphics card, 3D hardware accelerators with a product with a better price–performance ratio than existing products like those from 3dfx Interactive. Rapid changes in that market, notably with the introduction of OpenGL and Direct3D, led to rapid consolidation. PowerVR introduced new versions with low-power electronics that were aimed at the laptop computer market. Over time, this developed into a series of designs that could be incorporated into system-on-a-chip architectures suitable for handheld device use. PowerVR accelerators are not manufactur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Density
Pixels per inch (ppi) and pixels per centimetre (ppcm or pixels/cm) are measurements of the pixel density of an electronic image device, such as a computer monitor or television display, or image digitizing device such as a camera or image scanner. Horizontal and vertical density are usually the same, as most devices have square pixels, but differ on devices that have non-square pixels. Pixel density is not the same as where the former describes the amount of detail on a physical surface or device, the latter describes the amount of pixel information regardless of its scale. Considered in another way, a pixel has no inherent size or unit (a pixel is actually a sample), but when it is printed, displayed, or scanned, then the pixel has both a physical size (dimension) and a pixel density (ppi). Basic principles Since most digital hardware devices use dots or pixels, the size of the media (in inches) and the number of pixels (or dots) are directly related by the 'pixels per inch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM Frequency Bands
GSM frequency bands or frequency ranges are the cellular frequencies designated by the International Telecommunication Union, ITU for the operation of GSM mobile phones and other mobile devices. Frequency bands GSM frequency usage around the world A dual-band 900/1800 device is required to be compatible with most networks apart from deployments in ITU Region 2. GSM-900, EGSM/EGSM-900 and GSM-1800 GSM-900 and GSM-1800 are used in most parts of the world (ITU-Regions 1 and 3): Africa, Europe, Middle East, Asia (apart from Japan and South Korea where GSM has never been introduced) and Oceania. In common GSM-900 is most widely used. Fewer operators use GSM-1800. Mobile phones on aircraft, Mobile Communication Services on Aircraft (MCA) uses GSM-1800. In some countries GSM-1800 is also referred to as "Digital Cellular System" (DCS). GSM-850 and GSM-1900 GSM-1900 and GSM-850 are used in most of North, South and Central America (ITU-Region 2). In North America, GSM operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tessar
The ''Tessar'' is a photographic lens design conceived by the German physicist Dr. Paul Rudolph in 1902 while he worked at the Zeiss optical company and patented by Zeiss in Germany; the lens type is usually known as the Zeiss ''Tessar''. Since its introduction, millions of ''Tessar'' and ''Tessar''-derived lenses have been manufactured by Zeiss and other manufacturers, and are still produced as excellent intermediate aperture lenses. The ''Tessar'' design uses four spherical lens elements in three groups, one positive crown glass element at the front, one negative flint glass element at the center and a negative concave flint glass element cemented with a positive convex crown glass element at the rear. History File:Rudolph US444714A (Protar, 1890).svg, Zeiss ''Protar'' (aka ''Anastigmat''; Rudolph, 1890) File:Taylor US568052A (Cooke Triplet, 1893 Fig 11).svg, Cooke ''Triplet'' ( Taylor, 1893) File:Aldis GB16640-95 (Stigmatic, 1895).svg, Dallmeyer ''Stigmatic'' (Aldis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photodetector
Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical communication to scientific research and industrial automation. Photodetectors can be classified by their mechanism of detection, such as the photoelectric effect, photochemical reactions, or thermal effects, or by performance metrics like spectral response. Common types include photodiodes, phototransistors, and photomultiplier tubes, each suited to specific uses. Solar cells, which convert light into electricity, are also a type of photodetector. This article explores the principles behind photodetectors, their various types, applications, and recent advancements in the field. History The development of photodetectors began with the discovery of the photoelectric effect by Heinrich Hertz in 1887, later explained by Albert Einst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proximity Sensor
A proximity sensor (often simply prox) is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an Electromagnetic field, electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the electric field, field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive proximity sensor or photoelectric sensor might be suitable for a plastic target; an inductive sensor, inductive proximity sensor always requires a metal target. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between the sensor and the sensed object. Proximity sensors are also used in machine vibration monitoring to measure the variation in distance between a shaft and its support beari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerometer
An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change (mathematics), rate of change of velocity) of the object relative to an observer who is in free fall (that is, relative to an inertial frame of reference). Proper acceleration is different from coordinate acceleration, which is acceleration with respect to a given coordinate system, which may or may not be accelerating. For example, an accelerometer at rest on the surface of the Earth will measure an Gravitational acceleration, acceleration due to Earth's gravity straight upwards of about Standard gravity, ''g'' ≈ 9.81 m/s2. By contrast, an accelerometer that is in free fall will measure zero acceleration. Accelerometers have many uses in industry, consumer products, and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. In unmanned aerial vehicles, accelerometers help to stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphone
A microphone, colloquially called a mic (), or mike, is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, and radio and television broadcasting. They are also used in computers and other electronic devices, such as mobile phones, for recording sounds, speech recognition, Voice over IP, VoIP, and other purposes, such as Ultrasonic transducer, ultrasonic sensors or knock sensors. Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; the condenser microphone, which uses the vibrating Diaphragm (acoustics), diaphragm as a capacitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Keyboard
A computer keyboard is a built-in or peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or Push-button, keys to act as Mechanical keyboard, mechanical levers or Electronic switching system, electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input device, input method for computers since the 1970s, supplemented by the computer mouse since the 1980s, and the touchscreen since the 2000s. Keyboard keys (buttons) typically have a set of characters Engraving, engraved or Printing, printed on them, and each press of a key typically corresponds to a single written symbol. However, producing some symbols may require pressing and holding several keys simultaneously or in sequence. While most keys produce character (computing), characters (Letter (alphabet), letters, Numerical digit, numbers or symbols), other keys (such as the escape key) can prompt the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
