Input Devices PDF

ФАКУЛТЕТ ЗА ЕЛЕКТРОТЕХНИКА И ИНФОРМАЦИСКИ ТЕХНОЛОГИИ FACULTY OF COMPUTER SCIENCE AND ENGINEERING Input devices Human - computer communication ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Human - computer interface ◼ Input devices provide data and control signa...

ФАКУЛТЕТ ЗА ЕЛЕКТРОТЕХНИКА И ИНФОРМАЦИСКИ ТЕХНОЛОГИИ FACULTY OF COMPUTER SCIENCE AND ENGINEERING Input devices Human - computer communication ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Human - computer interface ◼ Input devices provide data and control signals to computer ◼ They convert user messages into sequences of electrical signals that computer “understands” ◼ Then, signal sequences are sent towards the computer ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Analog to digital ◼ The information users provide is (usually) given as a continuous range of values, i.e. the information is analog ◼ Information is translated into electronic impulses and signals of strictly ordered sequences consisting of “no impulse” and “impulse” ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Typical input devices ◼ Keyboard ◼ Pointing devices ◼ Imaging and video input devices ◼ Audio input devices ◼ Gaming devices ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Keyboard types ◼ PC keyboard ◼ Laptop keyboard with reduced dimensions and reduced number of keys ◼ Tablet keyboards  Touch screen  Virtual keyboard ◼ Thumb-sized (thumb-board) keyboards ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How is keyboard connected to computer? ◼ Keyboard can be connected  by a cable  wirelessly ◼ using radio waves with a radio-frequency (RF) which range from 27 MHz to up to 2.4 GHz ◼ using RF in the range of 2400–2483.5 MHz (Bluetooth) ◼ using infra-red (IR) signals ◼ Remote keyboards (external) ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Different keyboards (1) Retrieved from: https://www.typesofall.com/types-of-keyboard/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Different keyboards (2) Retrieved from: https://www.typesofall.com/types-of-keyboard/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Different keyboards (3) Retrieved from: https://www.logitech.com/  ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Different keyboards (2) Retrieved from https://www.typesofall.com/types-of-keyboard/ Retrieved from https://www.crn.com/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Separate keys of PC keyboard ◼ Alphanumeric ◼ Functional ◼ Navigation ◼ Numerical ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО The keyboard inside ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How keyboards work? ◼ Keyboards are “small computers”, with own microprocessor and memory ◼ Each key has a unique set of codes, even if, to the users, the keys seem identical ◼ Pressing a key causes a change in the amount of current flowing through a circuit associated specifically with that key ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Scan codes ◼ A microprocessor built into the keyboard constantly scans circuits leading to the keys. It detects the increase and decrease in the current from the key that has been pressed ◼ For each key two scan codes are generated:  one for when the key is pressed  one for when the key is released ◼ The processor stores the number in the keyboard’s own memory ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО BIOS / UEFI function ◼ The processor loads the number in a port connection where it can be read by the computer’s BIOS (basic input-output system) / UEFI (Unified Extensible Firmware Interface) ◼ Then the processor sends an interrupt signal over the keyboard cable to tell that the processor that a scan code is waiting for it. ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Virtual keyboards ◼ Virtual keyboards are software components that allow you to enter information without the use of physical keys. ◼ They generate text on the screen of the electronic device depending on which virtual keys displayed on the screen are touched by the user. ◼ Text is commonly entered either by tapping a virtual keyboard or by finger-tracing.  ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Virtual keyboard and virtual guitar Retrieved from http://www.apple.com Retrieved from https://support.apple.com/en- au/guide/garageband- ipad/chs39282a88/ipados ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Pointing devices ◼ A pointing device is an input interface that allows a user to input spatial data to a computer ◼ They input spatial data based on:  motion of an object (for example, hand-held mouse)  touching of a surface (for example, touch screen) ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Pointing devices based on motion of an object ◼ Mouse ◼ Trackball ◼ Joystick ◼ Pointing stick ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Mouse types ◼ Mechanical mouse ◼ Optical mouse ◼ Laser mouse ◼ Gyroscopic mouse ◼ 3D mouse ◼ Tactile mouse ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Mechanical mouse Retrieved from http://www.howstuffworks.com/mouse2.htm ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does a mechanical mouse work? (1) ◼ A ball turns in the direction of the movement ◼ It touches and turns two rollers mounted at a 90-degree angle to each other ◼ Each roller is attached to a wheel, known as an encoder. As the rollers turn, they rotate the encoders ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does a mechanical mouse work? (2) ◼ Each time a contact bar touches a point, an electric signal results ◼ Signals are sent to the PC over the impulse’s cable ◼ Tapping either of the buttons atop the mouse sends a signal to the PC which passes the signal to the software ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Optical mouse Retrieved from http://www.mousearena.com/laser-mouse-versus-optical-mouse/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does an optical mouse work? ◼ It contains an optoelectronic sensor (a tiny low-resolution video camera) that takes images 1500 times per second ◼ Imaging is supported by a light-emitting diode (LED) ◼ LED illuminates the surface the surface beneath their sensor and reflects the light toward complementary metal–oxide– semiconductor (CMOS) sensor ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО From CMOS to screen cursor ◼ CMOS sensor transmits the image to digital signal processor (DSP) ◼ DSP determines how much has the mouse moved from previous position and sends the coordinates to computer ◼ Computer moves the cursor on the screen ◼ Inspections are performed several hundred times per second ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Laser mice ◼ Have identical function as optical mice ◼ The only difference is that they use infrared laser diode instead of a LED to illuminate the surface beneath their sensor ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Laser mice Retrieved from https://www.javatpoint.com/what-is-a-laser-mouse ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Advantages of optical mice ◼ No moving parts ◼ No dust ◼ No pads ◼ Higher resolution leads to more efficient response ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Trackballs Retrieved from http://www.mousearena.com/ trackball-computer-mouse/ Retrieved from http://www.adesso-shop.com/index.php? main_page=product_info&cPath=5 _20& products_id=62 ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Trackball ◼ The ball is held by a socket containing sensors to detect a rotation of the ball about two axes A trackball has no limits on effective travel ◼ It can be a part of the keyboard of  Portablecomputers  Mobile phones ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Joysticks ◼ Predominantly used in electronic games ◼ Used for industrial purposes too (principal control device in the cockpit of many aircrafts) ◼ They contain:  theirown microprocessor  two independent axis of movement ◼ They enable independent movement through x and y axis ◼ Three-dimensional joysticks exist ◼ Special joysticks are used classed as assistive technology pointing devices ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Joystick collection Retrieved from https://www.extremetech.com/gaming/156711-evolution-of-video- game-controllers-leading-to-ps4-and-xbox-one ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Pointing stick ◼ Pointing stick is an isometric joystick ◼ It operates by sensing applied force ◼ It uses a pair of resistive strain gauges (gages) ◼ The speed of the pointer depends on the applied force Retrieved from http://www.notebookreview.com/default.asp?newsID=1610 ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Pointing devices based on touching a surface ◼ Graphical tablet ◼ Stylus ◼ Touchpad ◼ Touchscreen ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Graphical tablets Retrieved from http://www.carbodydesign.com/articles/2005/2005-09-08 -digital-car-design/2005-09-08-digital-car-design.php Retrieved from http://techniczone.com/graphic-tablet-reviews/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does a graphical tablet work? ◼ Tablet is a flat surface upon which the user may draw an image using an attached stylus ◼ It captures the image as a data ◼ It “interprets” the the angle of the pen, the pressure and the distance between the pen and the tablet ◼ Graphical tablets give much better precision than touchscreens ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Stylus (stylus pen) ◼ Primary input devices of personal digital assistants (PDA) and part of smart telephones Retrieved from http://forums.macrumors.com/showthread.php?t=544147 ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Touchpad (trackpad) ◼ Specialized surfaces that can translate the motion and position of a user's fingers to a relative position on screen ◼ Primarily used in self-contained laptop computers ◼ Some touch pads contain hotspots ◼ They offer additional functions, such as controlcontrolling the scrollbar ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Touchscreen ◼ Touchscreens enable user to interact directly with elements displayed on screen ◼ They can detect the presence and the exact position of the touch on the screen ◼ They are based on different sensors ◼ Sensors depend on the touchscreen type ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Touchscreen technologies ◼ Resistive touchscreen  Glass panel covered with a metallic layer of conductive connections and resistors ◼ Surface acoustic wave  Two capacitors placed on glass ◼ Capacitive sensing  Consists of an insulator (for example, glass), coated with a transparent conductor ◼ Infrared grid ◼ Optical imaging ◼ Acoustic pulse recognition ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Summary for pointing devices ◼ Enable input of spatial data to a computer ◼ Movements of the pointing device are echoed on the screen by movements of the pointer and other visual changes ◼ Pointing devices based on touching detect the movements and translate them into digital signals sent towards the computer ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Imaging and video input devices ◼ Scanner ◼ Optical character reader (OCR) ◼ Digital camera ◼ Specific scanners ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Image scanners ◼ Scanning mechanism is below a transparent glass window ◼ The scan head is moved slowly across the document ◼ Charge-coupled device (CCD) array converts light into electrons ◼ The image of the document is reflected by an angled mirror to another mirror. ◼ The last mirror reflects the image onto a lens ◼ The lens focuses the image through a filter on the CCD array  ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Various scanners https://epson.com/For- Home/Scanners/Photo- Scanners/Epson-Perfection- V600-Photo- https://en.wikipedia.or Scanner/p/B11B198011 g/wiki/Image_scanner https://www.pfu.ricoh.com/ global/scanners/fi/fi65f/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО AD converter ◼ Signals generated by diodes are analog ◼ Computer processes digital data ◼ The conversion of analog signals to digital data is performed by analog-to-digital converters (ADC) ◼ Digital information is stored in  Graphical format (as images)  Textual format after OCR processing ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Optical character recognition (OCR) ◼ Optical character recognition (OCR) recognizes:  whether the square on paper is white or black ◼ It combines neighbouring pixels into patterns and compares them to a stored glyph or characters ◼ OCR is performed by:  OCR devices (historically)  Specific software ◼ ABBYY FineReader 11 OCR ◼ Depends on the font, size and character style ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Specific scanners ◼ Linear or one-dimensional barcode reader  Parallel lines with variable widths and spacing ◼ Reader of matrix (two-dimensional) QR codes  Square dots arranged in square patterns ◼ Fingerprint and palm prints scanner  Process of comparing two instances of friction ridge skin impressions with stored dataset ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Barcode readers (scanners) ◼ A barcode reader (or bar code scanner) is an electronic device that can read and output printed barcodes to a computer. ◼ Data are presented as black/white stripes. ◼ Used for products, books … ◼ Barcode readers can be manual or stationary (embedded). ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does a barcode reader work? ◼ Reader scans the barcode as a picture, and then converts it into alphanumeric values. This value is sent towards the computer the reader is attached to. https://www.tutorialspoint.com/computer_fundamentals/co mputer_input_devices.htm ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО QR code scanners ◼ QR code = Quick Response Code ◼ First designed in 1994 for the automotive industry in Japan ◼ Used for marketing and commercial tracking applications (smartphone screen is used as a QR scanner) ◼ QR code reader generates URL https://en.wikipedia.org/wiki/QR_code ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Digital camera ◼ Digitize motion images ◼ Work similarly to scanners ◼ They are capable of capturing a large number of images during short periods ◼ Images are stored in long-term memories https://www.pcmag.com/picks/the- best-digital-cameras ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Audio input devices ◼ Microphone  Sound is digitized in audio (sound) card  It captures the sound (analog signal) and transmits it toward ADC chip ◼ MIDI keyboard ◼ Manipulation with digital signals is done by ROM instructions  ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Gaming devices ◼ Game controller ◼ Gamepads ◼ Wii controllers (for Nintendo) ◼ Kinect sensor devices (for Microsoft Xbox 360) https://www.ign.com/articles/2019/07/16 https://en.wikipedia.org/wiki/Classic_Controller /xbox-kinects-are-allegedly-being-used- as-surveillance-cameras ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Additional input devices ◼ Voice recognition ◼ Speech recognition ◼ GPS ◼ Sensors that collect data  Accelerometer  Gyroscope https://docs.idew.org/code-internet-of- things/references/physical- https://en.wikipedia.org/wiki/Gyroscope inputs/accelerometer ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Voice recognition devices https://idfive.com/agency/insights/preparing-website-voice- recognition-usability/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does GPS work (phase 1)? https://www.gethow.org/how-does-gps-global-positioning- system-works ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО How does GPS work (phase 2)? https://www.nationalgeographic.org/photo/triangulation-sized/ ФАКУЛТЕТ ЗА ИНФОРМАТИЧКИ НАУКИ И КОМПЈУТЕРСКО ИНЖЕНЕРСТВО Summary ◼ They can be digital (keyboard) or analog (most others) ◼ They (usually) retrieve analog information ◼ They digitize external information depending on  Mechanical movement  Audio signals  Video signals ◼ They are human-computer interfaces ◼ They can be two or three-dimensional