Engineering basics for computer interaction

Engineering basics for computer interaction
New Interaction Techniques Engineering basics for computer interaction Grigori Evreinov Department of Computer and Information Sciences University of Tampere, Finland Department of Computer and Information Sciences University of Tampere, Finland January – June, 2003

Device Capabilities and their Future Evolution
Engineering basics for computer interaction Device Capabilities and their Future Evolution KP-C50 PC Tag Writer TAUCHI MMIG G. Evreinov p 01_

many of today’s wireless devices use programmable microcontroller and digital-signal-processor cores combined with embedded memories and numerous peripheral modules all on a single chip microcontrollers are a specific type of microprocessor that have more I/O ports and interrupts than a general CPU as well as on-chip random-access memory (RAM) and read-only memory (ROM) external Flash and Burst Flash memories are also used future gadgets will be made to 0.1 µm designs, have more than 200 million transistors, operate at 500 MHz and work within 1V constraints processor cores will be configurable, and re-configurable processors will handle image, speech, data, web connectivity, mobile and in-home needs as devices and services become more complex the demands on memory will increase enormously TAUCHI MMIG G. Evreinov p 02_

within just the last 24 months, myriad audio, video, PDA and cellular products have equipped people not only to carry around data, images and audio but also to swap devices between various types of hardware new technologies include non-volatile flash memory cards and small disk drives flash memory cards have no moving parts and retain data in the absence of power memory is key to retaining complex data on a device it enables storage of programs, audio and video files and provides users with more efficient data compression methods sufficient memory also allows devices to run applications that require large amounts of memory to implement, like as Java etc TAUCHI MMIG G. Evreinov p 03_

two major subjects are to develop very high density magnetic medium and very sensitive reading head technology using Giant Magnetic Resistance Effects [3] Association of Super-Advanced Electronics Technology (ASET) TAUCHI MMIG G. Evreinov p 04_

IBM has demonstrated a GMR (Giant Magneto Resistive) head with an areal density capability greater than 35.3 billion bits per square inch and laboratory demonstrations up to 130 Gbits/in2 have been reported in the industry, indicating that future disk drives could exhibit capacities at least two times higher than today IBM Magnetic Hard Disc Drive Technology [5] TAUCHI MMIG G. Evreinov p 05_

added functionality implemented in recent 2G and 2.5G terminals source: UMTS (Universal Mobile Telecommunications System) Forum [1] TAUCHI MMIG G. Evreinov p 06_

the above-mentioned multifunctional devices are based on a mobile phone centric approach new multimedia and mixed data services would create further opportunities for UMTS devices to be complementary to other electronic devices considering the high level of complexity entailed in integrated multifunctional devices, a feasible approach is to enable traditional portable (consumer or business user) devices to interwork with UMTS terminals implementing core access functionality examples would include a digital camera interworking with a UMTS terminal, which would enable a user to transfer a digital image to the terminal for incorporation in a multimedia message the possible combinations are very wide ranging TAUCHI MMIG G. Evreinov p 07_

many different applications are expected to be implemented in UMTS devices for each application, corresponding additional components or elements need to be employed this will have some impact on the terminal design from a form factor perspective on the other hand, most users want to carry as small and as light a device as possible even though new functionality or features are added further miniaturization is one of the key issues and this requires further miniaturization or integration of all related components on UMTS devices TAUCHI MMIG G. Evreinov p 08_

several approaches for further integration and miniaturization LSI - Large Scale Integration LTCC - Low Temperature Co-fired Ceramics; integrate high frequency passive components into one ceramic substrate MEMs - MicroElectroMechanical Systems an advanced technology that makes possible to integrate passive elements into semiconductor MEMS is also known as micromachine technology source: Nikkei Electronics No. 782, cit. in [1] TAUCHI MMIG G. Evreinov p 09_

Trends in component technology
Engineering basics for computer interaction Trends in component technology TAUCHI MMIG G. Evreinov p 10_

Display technology Engineering basics for computer interaction
sometimes the user may be concerned more with viewing a screen than with listening to an ear piece the display represents the most important component in the future of communication perhaps users will interact through the display in many different environmental conditions for almost all device applications they will need to view high information content multimedia as well as the high bandwidth video the display is also likely to function as an input device through the use of ”soft keys” for effective interaction between users and displays, a direct-view display must be as large as possible within the constraints of a portable device TAUCHI MMIG G. Evreinov p 11_

no single display technology can currently satisfy all of requirements, like resolution, contrast / brightness, illumination, colour, frame rate, interface, bezel (non-display area), thickness, weight the simplest displays, including for mobile applications, are passive matrix displays a passive matrix display is an array of pixels, each of which contains an optical element that is sandwiched between column and row electrodes passive addressing via the column and row electrodes puts limitations on the achievable display resolution and levels of grey-scale that can be programmed at each pixel TAUCHI MMIG G. Evreinov p 12_

in STN Liquid Crystal Displays, the optical element is a Super Twisted Nematic (STN) liquid crystal that modulates (between 180 to 260 degrees resulting in better contrast) the transmission of light through polarisers positioned at each side of the liquid crystal cell STN materials have a sharp transmission-voltage response and a slow switching speed (e.g. >100ms), and as such are well suited to binary (black or white state) passive addressing, although 3-4 bit grey-scale can be achieved displays of this type are particularly suitable for text and simple graphics display, and this is sufficient for many of today’s low-bandwidth applications, while they have a limited viewing angle these reflective displays are very low power and are commonly illuminated by a (near white) LED, and are very cheap to manufacture TAUCHI MMIG G. Evreinov p 13_

higher performance colour STN LCDs offer desirable benefits for multimedia applications, though the introduction of colour filters can reduce total display brightness and increases the unit cost transflective technology helps ensure that pixels make the most of both ambient light and back-light sources although not capable of matching the performance of TFT (Thin Film Transistor) LCDs, the best CSTNs of today can achieve 65,000 colors for still images and 15 frames per second video at intermediate resolutions one of the more interesting technological developments is the move to plastic substrates; plastic STN LCDs offer lighter weight, greater impact resistance and the option to have custom (e.g. non-rectangular) display shapes TAUCHI MMIG G. Evreinov p 14_

these transistors do not generate light or color, an often-made mistake this is where the liquid crystals (LC) and their alignment come into play the transistors control the orientation of the LC, thus allowing them (LC) to pass (or not pass) light from the backlight XtraViewTM Wide Viewing Angle Technology [9] TAUCHI MMIG G. Evreinov p 15_

by having the electrodes on the same glass substrate, they allow the crystals to remain horizontal to the glass substrates in both the on and off states such design improves the viewing angle by passing the light through the crystals at their most efficient orientation – a horizontal orientation – thus dispersing the light more efficiently XtraViewTM Wide Viewing Angle Technology [9] TAUCHI MMIG G. Evreinov p 16_

organic electroluminescent (OEL) materials emit light in proportion to the current flowing through them, and have the advantages of high brightness and of being very thin higher performance displays are composed of active matrix pixels each pixel typically includes an optical element and switch the switch is an active component such as a TFT (thin-film transistor) or a TFD (thin-film diode), and is addressed by column (data) and row (scan) lines TFTs are normally fabricated from a thin-film of amorphous Silicon (a:Si); though complete construction of the TFT requires the deposition of several additional layers, including the addressing lines, today, this can be achieved with a minimum of five photolithographic masks, which keeps the cost of active matrix displays competitive TAUCHI MMIG G. Evreinov p 17_

four of the most common active matrix display cross-sections to maximize the use of ambient light, a single polariser can be used; micro-reflective structures and careful choice of colour filters can increase brightness at the expense of contrast ratio and of viewing angle source: UMTS Forum [1] TAUCHI MMIG G. Evreinov p 18_

although more expensive to manufacture than passive displays, the active matrix pixel switch permits a larger total number of pixels in the display, higher resolution, higher contrast and accurate grey-scale pixel programming in transmissive TFT LCDs, the optical element is usually a Twisted Nematic liquid crystal that modulates the transmission of light supplied by a back-light through orthogonal polarisers positioned at each side of the liquid crystal cell Twisted Nematic materials have a shallow transmission-voltage response and a fast switching speed (e.g. 25ms), and can therefore achieve 8-bit or higher RGB grey-levels (16 million colours) at 60 Hz updates (i.e. “true colour“ video) high performance active OEL displays based on poly-silicon TFTs are being considered since more than one of them can be implemented at each pixel to implement a small current-mode driver circuit this “pixel circuit“ is very power efficient and can minimize luminance non-uniformity across the display TAUCHI MMIG G. Evreinov p 19_

Low Temperature Poly-Silicon organic electroluminescent Super Twisted Nematic source: Advanced Data Research, Japan (11/09/00) [1] TAUCHI MMIG G. Evreinov p 20_

Input devices Engineering basics for computer interaction
usability is a key issue affecting both the implementation of applications and device design unification of input methods is an important factor in realizing “easy to use” user interfaces, but unification of new features could bring complexity to users to understand which input device is doing which function and/or feature some UMTS devices will have similar input methods and components like current mobile units (keypad and pointing device), others may employ touch screens and voice recognition devices should not only support the display of character encodings and character sets in supporting internationalized content in local languages, they must also allow for the input of text in those local languages the support of character encodings that work across multiple languages, such as Unicode and UTF-8, as well as the most popular encoding types in use on the Internet today is vital to the widespread availability of localized and internationalized content and services TAUCHI MMIG G. Evreinov p 21_

Engineering basics for computer interaction Keyboards and keypads
a basic requirement for a mobile unit input device is to employ at least ten keys for activating the phone and the line and for inputting telephone numbers for this basic feature, most current mobile phones employ between 14 and 17 keys, normally realized using carbon printed or gold flashed substrate combined with a carbon printed rubber sheet, poly-dome sheet or metal contact sheet reliability is becoming an increasingly important factor as mobile phones change from voice-oriented to games-oriented usage for i-mode phones in Japan, the minimum life cycle for the key panel has to guarantee at least one million contact cycles small form factors as well as the use of hands free kit result in phones being carried in users’ pockets for much of the time; sensitivity to moisture from the human body becomes an issue TAUCHI MMIG G. Evreinov p 22_

direct membrane/polydome switches printed circuit board contact patterns the most important single design objective is to provide as many shorting paths as possible so best switch operation can be realized when the button is actuated indirect full-travel membrane switch switch technologies [10] TAUCHI MMIG G. Evreinov p 23_

wire-free soft technology Engineering basics for computer interaction demo 1 the three modes of ElekTex™ sensor operation - position sensing (X-Y positioning), pressure measurement (Z sensing) and switch arrays – are normally achieved through four connections to each fabric interface TAUCHI MMIG G. Evreinov p 23_

1. rubber keypad (non-conductive) 2. spacer/Adhesive 3. membrane/polydome layer with conductive ink 4. spacer/Adhesive 5. PCB 6. conductive ink sample designs illustrating indirect polydome construction this width should be same as length of key-travel + 0.2mm Printed Circuit Board (PCB) design for use with membrane/polydome switches Logistic Design (UK) Ltd. [12, 13] TAUCHI MMIG G. Evreinov p 24_

the snap ratio (or click ratio) of any conductive rubber keypad directly affects the tactile feel realized by the operator keypads with snap ratios of % have excellent tactile feel and relatively long life, while keypads with snap ratios below 30% have relatively weak tactile feel, but longer life dual-durometer keypads also improve tactile feel the snap ratio of any keypad can be calculated by working with the formula F1-F2 divided by F1, where F1 is the actuation force and F2 is the contact force ICHIA Technologies Inc. [11] TAUCHI MMIG G. Evreinov p 25_

it is very difficult to recommend specific guidelines for creating best tactile feel however, if actuation force and stroke are identified for a given application, it is possible to design a keypad's switch membranes precisely to realize the identified parameters a very general guideline that can be followed for developing good tactile feel is to specify higher actuation forces for keypads with large keys than those with small keys this rule also applies to key heights: tall keys require higher actuation forces than short keys ICHIA Technologies Inc. [11] TAUCHI MMIG G. Evreinov p 26_

another typical guideline for actuation force is to specify a minimum actuation force of grams for keys with heights of mm and a minimum actuation force of grams for keys with heights of mm care should be taken when designing tactile feel so a minimum return force of 30 grams is realized this minimum return force will help greatly to eliminate the potential problem of sticking keys, as will proper bezel design [11] even though it is possible to use ten keys for writing s or inputting characters, this would not be acceptable to users other solutions have to be considered today, several sub-systems and technologies are already available to support these requirements; some have already been used in market products TAUCHI MMIG G. Evreinov p 27_

separate small keyboards are available for current mobile units and PDAs pen-input technology (touch screen, track pad and click) or voice recognition technology could also improve usability as alternatives to keypad-based input methods in terms of keypad features, lessons should be drawn from past industry oversights concerning different digits and alphanumeric layouts on device keypads with the trend towards even more innovative device features and designs that go beyond conventional keypads - often incorporating icons, pictograms, and symbols for interaction and inputting instead of keys - there are new sets of usability challenges to be met by the UMTS device sector TAUCHI MMIG G. Evreinov p 28_

Engineering basics for computer interaction Pointing devices
beside keypads, some recent mobile units employ so-called “pointing devices” that allow the user to scroll the menu or to select a subject on the display many different kinds of pointing devices have been implemented onto mobile applications for such usage currently available surface mounted devices (SMD input devices) for mobile phones: (a) top-faced slide switch with centre push; (b) side-faced slide switch with centre push; (c) small rotary encoder (Jog); (d) 4-directional switch with centre push; (e) very small rotary encoder source : ALPS Electric Co., Ltd [2] TAUCHI MMIG G. Evreinov p 29_

film GlidePoint slide potentiometers low-profile type TACT & mechatronic detection switches small rotary encoder colorless tablet with a high transparency of 88%; deadspace of 2.0 mm; micro dot spacers to maintain visibility hollow shaft encoders for level control 8-Directional operating switches with thin center-push switch source : ALPS Electric Co., Ltd [2] TAUCHI MMIG G. Evreinov p 30_

Engineering basics for computer interaction pressure sensitive direction devices provide a user interface to facilitate user navigation through increasingly complex menu structures pressure sensitive direction switches H01C 010/46 USA Pat. No 6,313,731 TAUCHI MMIG G. Evreinov p 31_

the round grid pattern for directional navigation are shown, where the signal and output contact regions U, D, L, R, G are circumferentially displaced and arranged in a circular pattern capacitive pointing stick apparatus G09G 005/08 USA Pat. No 6,437,772 pressure sensitive direction switches H01C 010/46 USA Pat. No 6,313,731 TAUCHI MMIG G. Evreinov p 32_

multi-directional symbol input [7] X-conductors (24) and Y-conductors (25) are placed on a flexible base plate (26); the membrane (28) and the contacts (29) are located under the base plate (26); the membrane (28) and the contacts (29) form a dome switch the X-conductors (24) and the Y-conductors (25) are electrically connected to a Module of Measuring Touch Point Coordinates (30) which electrically interacts with a Module of Analysis of Lateral Movement Trajectory (31); an Interface Module (32) interacts with both the Module of Analysis of Lateral Movement Trajectory (31) and a Module of Mechanical Keypad (33) to which dome contacts (34) are connected TAUCHI MMIG G. Evreinov p 33_

switch technologies [10] contact switch capacitive magnetic reed ferrite core mercury contact TAUCHI MMIG G. Evreinov p 34_

capacitance switch with a compression spring resistance increases until switch closure this poor responsiveness is disturbing for most situations, and unacceptable for repetitive use (due to the increased risk of RSI), so is rarely found in contemporary products bent spring the bent spring, though more expensive, provides slightly better feedback than electrometric mat underlay (with domes under each key) switch technologies [10] TAUCHI MMIG G. Evreinov p 35_

pressure-actuated pointing device [14] the magnitude of the applied positive pressure gradient and point of pressure application on the finger pad determine the magnitude and direction of the cursor's displacement on the graphics screen TAUCHI MMIG G. Evreinov p 36_

tongue touch keypad is the “keyboard” that utilizes key chording this device is available for quadriplegics who need in computer access the keypad contains a miniature circuit board with a nine-button keypad and radio transmitter that fits into a standard dental retainer worn in the roof of the mouth TAUCHI MMIG G. Evreinov p 37_

a pair of ear-microphones output signals were examined to detect the side of teeth-chattering, right or left at discriminator block [Hashimoto, Yonezawa and Itoh 15] TAUCHI MMIG G. Evreinov p 38_

tonguepoint is an isometric tongue pointing device was developed in IBM Almaden Research Center [16] a tonguepoint is a mouthpiece that, similar to a dental night guard or a sports mouth guard, is form fitted to each individual's upper teeth and hard pallet because of this fixture the user may relax at normal jaw posture when wearing the mouthpiece speaking with the tonguepoint inserted in the mouth is also feasible Die Zungensteuerung (PROTOS System) TAUCHI MMIG G. Evreinov p 39_

analog button the analog button and testing software has also been designed in TAUCHI Unit a pilot investigation was carried out to study behavior patterns in hand-eye coordination and some new strategies of their exploitation the results suggest that there is potential for further development and applications of these alternative input devices to control by different entities (menu pointing, scrolling, etc.) of information environment TAUCHI MMIG G. Evreinov p 40_

TAUCHI MMIG G. Evreinov p 41_

pointing devices can improve usability for specific applications and functionality applications such as mobile gaming will require dedicated pointing devices to satisfy the “easy to play” principle for users development trends for pointing devices focus on further miniaturization and the ability to deploy re-flow soldering techniques on current devices already employed in consumer electronic products IR LED IR-Photodiode TAUCHI MMIG G. Evreinov p 42_

Cameras Engineering basics for computer interaction
Complementary Metal-Oxide Semiconductor (CMOS) image sensors have been highlighted recently with a smaller size and reduced weight as a candidate technology for integrating digital camera capability into mobile phones CMOS image sensors offer lower power consumption and a much smaller physical integration area than the Charge-Coupled Device (CCD) image sensors which are conventionally used for digital still cameras and camcorders that require high picture quality for a long time CMOS image sensors have been “a modest product” lagging CCD image sensors as most image sensors were designed for high picture quality products CMOS image sensors have been accepted only for certain products that focus on low power consumption rather than picture quality demo 2 TAUCHI MMIG G. Evreinov p 43_

the latest CMOS sensor technology could bring around 110,000-pixel (that is, based on 352 x 288 pixels, they can provide Common source Intermediate Format (CIF) compliant quality levels) with 1/7” optics, a form factor of < 101010 mm3 and low consumption of < 100mW CCD could bring 350,000 ~ 380,000-pixel with 1/6” optics however, the physical integration area is rather bigger than that for CMOS sensors as CCD requires 3-4 different supply voltages and power consumption for CCD is still over 200mW the next opportunity for image sensors would be to satisfy the requirements of the PDA and notebook PC markets TAUCHI MMIG G. Evreinov p 44_

an image sensor must achieve 640 x 480 dots, or Video Graphics Array (VGA) compliant CMOS and CCD image sensors will be competing technologies in sensor market that needs products with a resolution of VGA-compliant quality CMOS image sensors used in dark environments suffer deterioration in colour production quality and increase of output noise CCD image sensors offer better quality but rather high power consumption as well as a larger integration area CMOS image sensors are facing the challenge of improving picture quality along with downsizing whilst CCD image sensors are facing the challenge of reducing their size and power consumption TAUCHI MMIG G. Evreinov p 45_

proximity detector for a seeing eye mouse motion produces successive frames of translated patterns of pixel information, which are compared by autocorrelation to ascertain the direction and amount of movement [6] a hold feature suspends the production of movement signals to the computer, allowing the mouse to be physically relocated on the work surface without disturbing the position on the screen of the pointer TAUCHI MMIG G. Evreinov p 46_

Solid-State Optical Mouse Sensor the HDNS-2000 is a reflective optical sensor that provides a non-mechanical tracking engine for implementing a computer mouse it is based on optical navigation technology which measures changes in position by optically acquiring sequential surface images (frames) and mathematically determining the direction and magnitude of movement the sensor is mounted in a plastic optical package and designed to be used with the HDNS-2100 (Lens), HDNS-2200 (LED Assembly Clip), and HLMP-ED80 (High Light Output 639 nm LED), providing a complete and compact tracking engine this optical tracking engine has no moving parts and requires no precision optical alignment resolution is specified as 400 cpi (characters per inch) at rates of motion up to 12 inches per second source: Agilent Technology [3] TAUCHI MMIG G. Evreinov p 47_

source: Agilent Technology [3] TAUCHI MMIG G. Evreinov p 48_

virtual keyboard with one CCD camera [17] Fingertip Detector outputs a list of fingertips’ 2-D coordination only if fingertips were detected; Stroke Detector watches the alternation of the moving vectors of each fingertip; Keyboard Checker translates fingertip’s coordinates detected as stroke to user-defined key character TAUCHI MMIG G. Evreinov p 49_

a full-size virtual keyboard can be projected by light on to any surface [18, 19] it can be integrated into mobile phones, laptops, tablet PCs or even sterile medical environments the keyboard, manufactured by Developer VKB Inc, in Israel ( ) the mini projector that detects user interaction with the surface also simulates a mouse pad (Hanover, Germany, CeBIT 2002) TAUCHI MMIG G. Evreinov p 50_

Demo 3 facial gesture musical interfaces [20] the musculature of the face allows for fine motor control of actions so it is interesting to explore the possibility of machine interfaces that are driven by facial action because facial action is involved in both speech production and emotional expression, there is a rich space of intuitive gesture to sound mappings for face action TAUCHI MMIG G. Evreinov p 51_

Body motions [32] secondbig.jpeg TAUCHI MMIG G. Evreinov p 52_

human movement tracking technology [24] TAUCHI MMIG G. Evreinov p 53_

muscle twitch switches are activated by muscle contraction they can be used with eyebrow movement and finger flexion [21] reed switch magnet TAUCHI MMIG G. Evreinov p 54_

“Body Coupled FingeRing”: Wireless Wearable Keyboard [30] the transmitter (TX) mounted on the base of finger and the receiver (RX) mounted on the wrist TAUCHI MMIG G. Evreinov p 55_

Senseboard [ works by tracking the muscle movements in the palm of the hand: when you extend your left pinky finger in midair and strike it down as if you were going to strike the "Q" key Senseboard displays the letter "Q" on the monitor Samsung's Scurry works by attaching motion sensors to each finger; It doesn't detect muscle movement, but rather uses gyroscopic technology to detect angular movements of fingers through space this approach works better, however, both devices are too bulky [ ] Samsung Scurry wearable keyboard Futurelooks.com TAUCHI MMIG G. Evreinov p 56_

GestureWrist is a wristband-type input device that recognizes hand gestures and forearm movements unlike DataGloves or other hand gesture-input devices, all sensing elements are embedded in a normal wristband GesturePad is a sensing module that can be attached on the inside of clothes, and users can interact with this module from the outside it transforms conventional clothes into an interactive device without changing their appearance TAUCHI MMIG G. Evreinov p 57_

measuring wrist-shape, forearm movements and gestures [34] TAUCHI MMIG G. Evreinov p 58_

clothes as communication surfaces [34] TAUCHI MMIG G. Evreinov p 59_

SmartSkin: An Infrastructure for Freehand Manipulation on Interactive Surfaces [35] demo4 demo5 TAUCHI MMIG G. Evreinov p 60_

demo6 the Gesture Wall [36-38] injected a 50100 kHz signal into the body of the user through an electrode on the floor; the strengths of this signal, as capacitively received at electrodes placed in the four corners of the display, were used to track the position of a hand as it moved around the display surface although this system was very sensitive to gesture, it required fairly stiff postural constraints on the part of the user - one hand forward and body back, since the entire body radiates the transmit signal, not just the hand to be tracked TAUCHI MMIG G. Evreinov p 61_

tactile array sensor top: exploded view showing sensor construction bottom: side view showing the crossed layers of copper strips separated by silicone rubber spacers a protective rubber coating is added on the contact surface [26] TAUCHI MMIG G. Evreinov p 62_

infant health monitoring system [27] TAUCHI MMIG G. Evreinov p 63_

dynamic system for determining human physical instability [28] a dynamic system adapted to test a human subject to determine the degree to which his physical stability is impaired without regard to the cause of impairment electronic sensors are mounted on the platform yield signals which depend on the deviation of the platform from the X and Y axes when the subject standing on the platform shifts his weight thereon to change the orientation of the platform, the resultant signals are indicative of the degree to which the stability of the subject is impaired TAUCHI MMIG G. Evreinov p 64_

respiration and movement monitoring system [29] a monitoring system (10) includes a first sensor (12) for detecting the respiration and/or movements of an infant (14), and a sensor (18) for detecting the presence or movement of the infant or proximal objects (20); an accelerometric sensor (22) detects movements of a platform (16); an audio sensor (24) detects sounds associated with the infant or proximal objects none of the sensors are physically attached to the infant the high-impedance element and the sensor forming a voltage divider that produces from the signal a sensor voltage that is proportional to the impedance of the first sensor TAUCHI MMIG G. Evreinov p 65_

elastic porous non-conductor elastic conductor + 5V Ix Gnd Iy PadGraph is a registrar of body motions based on capacitive sensors [22] TAUCHI MMIG G. Evreinov p 66_

HoloWall is a wall-sized computer display that consists of a glass wall with rear-projection sheet behind it a video projector displays images on the wall, while inputs are recognized with infrared (an array of IR LEDs) and a video camera with an IR filter (840 nm) installed behind the wall when a user moves a finger close enough to the screen (0-30 cm, depending on the threshold value of the recognition software), it reflects IR light and thus becomes visible to the camera through image processing technique, the finger shape can be separated from the background [33] TAUCHI MMIG G. Evreinov p 67_

schematic of haptic interaction system based on Lorentz force magnetic levitation [40, 41] TAUCHI MMIG G. Evreinov p 68_

Magnetic Imaging System of Virtual Objects in Haptic Space [42] a detection of density gradient of magnetic field through the small “probe-magnet” (5) coupled to the finger TAUCHI MMIG G. Evreinov p 69_

experimental setup for magnetic imaging system 1 - cardboard box; 2 - constant magnets; 3 - the probe magnet; 4 - a copying-paper; 5 - distance control (attenuation of magnetic field) TAUCHI MMIG G. Evreinov p 70_

Communication With PC Input & Output capabilities
Engineering basics for computer interaction Communication With PC Input & Output capabilities TAUCHI MMIG G. Evreinov p 71_

Joystick Port Engineering basics for computer interaction
the joystick interface card was designed to be as simple and cheap as possible the card consisted only of bus interface electronics and four monostable multivibrators (in 558 chip) those monostable multivibrators were simple timer circuits which put out a pulse with width directly proportional to the joystick resistance value the pulse width was then measured using software loop source: Joysticks and other game controllers [43-45] TAUCHI MMIG G. Evreinov p 72_

pin purpose 1 potentiometer common (Joy A) 2 button (Joy A) 3 X coordinate potentiometer (Joy A) 4 button common (Joy A) 5 button common (Joy B) 6 Y coordinate potentiometer (Joy A) 7 button (Joy A) 8 unused 9 potentiometer common (Joy B) 10 button (Joy B) 11 X coordinate potentiometer (Joy B) 12 MIDI TXD (transmit) (computer-> midi) 13 Y coordinate potentiometer (Joy B) 14 button (Joy B) 15 MIDI RXD (midi -> computer) the joystick consists of two potentiometers with variable resistance value between 0 Ohm and 100 kOhm (in some joysticks up to 150 kOhm) the potentiometer resistances have the minimum values when the joystick is at the top left position one end of the potentiometer is connected to +5V pin and the center pin is connected top the analogue input of the joystick TAUCHI MMIG G. Evreinov p 73_

to read the joysticks (or your slide potentiometer positions), you must first write a byte to port 201h, this triggers the 558 timer on the game adapter it doesn't matter what value you send, as long as you perform an I/O write Game port 201h byte: | | | | | | | | | | but4 | but3 | but2 | but1 | stk4 | stk3 | stk2 | stk1 | the most machine-independent way to sample the game port is to use a timer NOTE the time just before you trigger the 558 (e.g., read the countdown register in Timer 0, you need pretty fine resolution and this timer performs counts every 55 ms) after triggering, sit in a loop reading port 201h and examining bits 0-3 for those bits that have a joystick potentiometer attached, you'll see them sit for a while at 0, then become 1 as each bit flips back to 1, note the time again when all bit 0-3 have flipped back to 1, you're almost done compute elapsed time for each bit, and you end up with a value that is proportional to potentiometer position TAUCHI MMIG G. Evreinov p 74_

potentiometers are normally 0-150k variable resistors, and according to the IBM techref, the time is given by Time = 24.2e-6s e-6s * R/Ohms this equation does not accurately represent the real situation, where there are differences in absolute components values in reality you have to calibrate the joystick for the application you use the most straightforward way to calibrate the stick for the program is to record the values the joystick gives in extreme positions and in the center position buttons can be read at any time just by reading port 201h and looking at bits 4-7 No triggering is required button bits are normally 1; while a button is depressed, its bit will flip to 0 TAUCHI MMIG G. Evreinov p 75_

Parallel Port Engineering basics for computer interaction
25-way Female D-Type Connector the original IBM-PC's Parallel Printer Port (the Standard Parallel Port (SPP)) had a total of 12 digital outputs and 5 digital inputs accessed via 3 consecutive 8-bit ports in the processor's I/O space [46-47] 8 output pins accessed via the DATA Port 5 input pins (one inverted) accessed via the STATUS Port 4 output pins (three inverted) accessed via the CONTROL Port The remaining 8 pins are grounded source: Use of a PC Printer Port for Control and Data Acquisition [46-47] TAUCHI MMIG G. Evreinov p 76_

various enhanced versions of the original specification have been introduced over the years Bi-directional (PS/2) Enhanced Parallel Port (EPP) Extended Capability Port (ECP) each printer port consists of three port addresses; data, status and control port these addresses are in sequential order; that is, if the data port is at address &H378 the corresponding status port is at &H379 and the control port is at &H37a Printer Port Data Status Control LPT1 &H3bc &H3bd &H3be LPT2 &H378 &H379 &H37a LPT3 &H278 &H279 &H27a TAUCHI MMIG G. Evreinov p 77_

Pin (25 pin connector) & Port (bit) Assignments on the three ports [46] TAUCHI MMIG G. Evreinov p 78_

in normal printing STROBE is high all outputs on the Data Port are true logic; that is, writing a logic one to a bit causes the corresponding output to go high however, the /SELECT_IN, /AUTOFEED and /STROBE outputs on the Control Port have inverted logic; that is, outputting a logic one to a bit causes a logic zero on the corresponding output this adds some complexity in using the printer port, but the fix is to simply invert those bits using the exclusive OR function prior to outputting why the designers of the printer port used inverted logic? assume you have a printer with no cable attached an open usually is read as a logic one; thus, if a logic one on the SELECT_IN, AUTOFEED and STROBE leads meant to take the appropriate action, an unconnected printer would assume it was selected, go into the autofeed mode and assume there was data on the outputs associated with the Data Port the printer would be going crazy when in fact it wasn't even connected [46] TAUCHI MMIG G. Evreinov p 79_

Printer Port - Typical Application [46] NOTE, 5V is an external source Logic 1 on output DATA 0 (Data Port - Bit 0) causes LED to be off Logic 0 causes LED to turn on normally open push-button causes +5V (logic 1) to appear on input BUSY (STATUS PORT - Bit 7) when depressed, push-button closes and ground (logic 0) is applied to input Busy when idle (waiting), push-button is open and LED is off on depressing push-button, LED blinks on and off at nominally 5 pulses per second TAUCHI MMIG G. Evreinov p 80_

Serial RS232 Port Engineering basics for computer interaction
what are the advantages of using serial data transfer rather than parallel? the serial port transmits a '1' as -3 to -25 volts and a '0' as +3 to +25 volts where as a parallel port transmits a '0' as 0v and a '1' as 5v therefore the serial port can have a maximum swing of 50V compared to the parallel port which has a maximum swing of 5 Volts therefore cable loss is not going to be as much of a problem for serial cables than they are for parallel if the device needs to be mounted a far distance away from the computer then 3 core cable (Null Modem Configuration) is going to be a lot cheaper that running 19 or 25 core cable source: TAUCHI MMIG G. Evreinov p 81_

many palmtop computers and microcontrollers have in built SCI – Serial Communications Interfaces Serial Communication reduces the pin count of these MPU's only two pins are commonly used, Transmit Data (TXD) and Receive Data (RXD) compared with at least 8 pins if you use a 8 bit Parallel method + Strobe the serial transmission is used where one bit is sent at a time IrDA-1 (the first infra red specifications) was capable of 115.2k baud and was interfaced into a UART (Universal Asynchronous Receiver / Transmitter) the pulse length however was cut down to 3/16th of a RS232 bit length to conserve power TAUCHI MMIG G. Evreinov p 82_

the electrical specifications of the serial port is contained in the EIA (Electronics Industry Association) RS232C standard, tt states many parameters such as - 1. a "Space" (logic 0) will be between +3 and +25 Volts 2. a "Mark" (Logic 1) will be between -3 and -25 Volts 3. the region between +3 and -3 volts is undefined 4. an open circuit voltage should never exceed 25 volts (in Reference to GND) 5. a short circuit current should not exceed 500mA, the driver should be able to handle this without damage TAUCHI MMIG G. Evreinov p 83_

Abbreviation Full Name Function TD Transmit Data Serial Data Output (TXD) RD Receive Data Serial Data Input (RXD) CTS Clear to Send this line indicates that the Modem is ready to exchange data DCD Data Carrier Detect when the modem detects a "Carrier" from the modem at the other end of the phone line, this Line becomes active DSR Data Set Ready this tells the UART that the modem is ready to establish a link DTR Data Terminal Ready this is the opposite to DSR. This tells the Modem that the UART is ready to link RTS Request To Send this line informs the Modem that the UART is ready to exchange data RI Ring Indicator goes active when modem detects a ringing signal from the PSTN TAUCHI MMIG G. Evreinov p 84_

above is the standard port addresses, which should work for most PC's if IBM P/S2 has a micro-channel bus, then expect a different set of addresses and IRQ's TAUCHI MMIG G. Evreinov p 85_

USB Port or Universal Serial Bus [50]
Engineering basics for computer interaction USB Port or Universal Serial Bus [50] the original motivation for the Universal Serial Bus (USB) came from three interrelated considerations: connection of the PC to the telephone the USB provides a ubiquitous link that can be used across a wide range of PC-to-telephone interconnects ease-of-use the PC’s I/O interfaces, such as serial/parallel ports, keyboard /mouse /joystick interfaces, etc., do not have the attributes of plug-and-play port expansion the lack of a bi-directional, low-cost, low-to-mid speed peripheral bus has held back the creative proliferation of peripherals such as telephone/fax/modem adapters, answering machines, scanners, PDA’s, keyboards, mice, etc. existing interconnects are optimized for one or two point products as each new function or capability is added to the PC, a new interface has been defined to address this need TAUCHI MMIG G. Evreinov p 86_

the more recent motivation for USB 2.0 stems from the fact that PCs have increasingly higher performance and are capable of processing vast amounts of data at the same time, PC peripherals have added more performance and functionality user applications such as digital imaging demand a high performance connection between the PC and these increasingly sophisticated peripherals USB 2.0 addresses this need by adding a third transfer rate of 480 Mb/s to the 12 Mb/s and 1.5 Mb/s originally defined for USB USB is a fast, bi-directional, isochronous, low-cost, dynamically attachable serial interface that is consistent with the requirements of the PC platform of today and tomorrow TAUCHI MMIG G. Evreinov p 87_

the USB is a cable bus that supports data exchange between a host computer and a wide range of simultaneously accessible peripherals the attached peripherals share USB bandwidth through a host-scheduled, token-based protocol the bus allows peripherals to be attached, configured, used, and detached while the host and other peripherals are in operation the USB transfers signal and power over a four-wire cable the signaling occurs over two wires on each point-to-point segment TAUCHI MMIG G. Evreinov p 88_

USB data transfers take place between host software and a particular endpoint on a USB device, such associations are called pipes data movement though one pipe is independent from the data flow in any other pipe, a given USB device may have many pipes; while one supports transporting data to the USB device, another supports transporting data from the USB device the USB architecture comprehends four basic types of data transfers: Control Transfers: used to configure a device at attach time and can be used for other device-specific purposes, including control of other pipes on the device Bulk Data Transfers: generated or consumed in relatively large and bursty quantities and have wide dynamic latitude in transmission constraints Interrupt Data Transfers: used for timely but reliable delivery of data, for example, characters or coordinates with human-perceptible echo or feedback response characteristics Isochronous Data Transfers: occupy a prenegotiated amount of USB bandwidth with a prenegotiated delivery latency (also called streaming real time transfers) TAUCHI MMIG G. Evreinov p 89_

Hubs are a key element in the plug-and-play architecture of the USB, serve to simplify USB connectivity from the user’s perspective and provide robustness at relatively low cost and complexity hubs are wiring concentrators and enable the multiple attachment characteristics of the USB Hubs in a Desktop Computer Environment [50] TAUCHI MMIG G. Evreinov p 90_

hubs can detect attach and detach at each downstream port and enable the distribution of power to downstream devices; each downstream port can be individually enabled and attached to either high-, full- or low-speed devices a USB 2.0 hub consists of three portions: the Hub Controller, the Hub Repeater, and the Transaction Translator the Hub Repeater is a protocol-controlled switch between the upstream port and downstream ports, has reset and suspend/resume signaling the Host Controller provides the communication to/from the host; hub-specific status and control commands permit the host to configure a hub and to monitor and control its ports the Transaction Translator provides the support of full-/low-speed devices behind the hub, while transmitting all device data between the host and the hub at high-speed TAUCHI MMIG G. Evreinov p 91_

Data Encoding/Decoding the USB employs NRZI* data encoding when transmitting packets in NRZI encoding, a “1” is represented by no change in level and a “0” is represented by a change in level the high level represents the J state on the data lines a string of zeros causes the NRZI data to toggle each bit time a string of ones causes long periods with no transitions in the data J a data stream and the NRZI Data Encoding Non Return to Zero Invert (NRZI) - a method of encoding serial data in which ones and zeroes are represented by opposite and alternating high and low voltages where there is no return to zero (reference) voltage between encoded bits, eliminates the need for clock pulses TAUCHI MMIG G. Evreinov p 92_

Universal Serial Bus Revision 2.0 specification [50, 51] (.zip, 6.50 MB, 650 pages!) provides the technical details to understand USB requirements and design USB compatible products (12/21/2000) the Enhanced Host Controller Interface (EHCI) specification [52]describes the register-level interface for a Host Controller for the Universal Serial Bus (USB) Revision 2.0. The specification includes a description of the hardware/software interface between system software and the host controller hardware. Some key features of the EHCI specification are: Full, Robust Support for all USB 2.0 Features Low-risk support for Full- and Low-speed peripherals System Power Management Provides simple, robust solutions to USB 1.1 Host Controller Issues Optimized for Best Memory Access Efficiency Minimized Hardware Complexity Support for 32 and 64-bit Addressing TAUCHI MMIG G. Evreinov p 93_

References Engineering basics for computer interaction
[1] Key Components for 3G Devices, Report No. 15 from the UMTS Forum, January [2] ALPS Electric Co., Ltd [3] Mouse sensors for optical navigation. Datasheets are available at: [4] Association of Super-Advanced Electronics Technology, [5] IBM Magnetic Hard Disk Drive Technology, [6] Gordon, et al, Proximity detector for a seeing eye mouse, Agilent Technologies, Inc. (Palo Alto, CA), G09G 005/08, USA Pat 6,281,882 [7] Multi-directional symbol input, [8] Subramanian, V. Fabrication of thin film transistors for Liquid Crystal Display applications. ESCI 577 Literature Review Report. [9] XtraViewTM Wide Viewing Angle Technology, financial/downloads/xtraview.pdf [10] Griffin, T. Haptic Feedback in Button Technologies, 1999, [11] Force / Travel Diagram, ICHIA Technologies Inc. [12] Logistic Design (UK) Ltd. [13] Logistic Design (UK) Ltd. [14] Gervais, J-Ph. A.F.M., Pressure-actuated pointing device, G09G 003/02, USA Pat. No 5,508,719 [15] Hashimoto, M., Yonezawa, Y. and Itoh, K. New mouse-function using teeth-chattering and potential around eyes for the physically challenged. In: Interdisciplinary Aspects in Computers Helping People with Special Needs. 5th Int. Conf. ICCHP'96 Linz, Austria, July R. Oldenbourg Verlag GmbH Munich, Germany, Part 1, pp TAUCHI MMIG G. Evreinov p 94_

[16] Salem, C. and Zhai, S. An Isometric Tongue Pointing Device, IBM Almaden Research Center [17] Nozomu MATSUI and Yoshikazu YAMAMOTO, A New Input Method of Computers with One CCD Camera: Virtual Keyboard, INTERACT’01, pp , [18] The full-size virtual keyboard, , [19] Kolsch, M. and Matthew Turk, M., Keyboards without Keyboards: A Survey of Virtual Keyboards, [20] Facial Gesture Musical Interfaces, [21] Muscle Twitch Switches, [22] Evreinov G., Agranovski A., Yashkin A., Evreinova T. PadGraph. In: Human-Computer Interaction: Communication, Cooperation, and Application Design, Vol. 2 of the Proc. of HCI International '99, Munich, Germany, August 22-26, Hans-Jorg Bullinger and Jurgen Ziegler (eds.) Lawrence Erlbaum Associates, Publishers Mahwah, New Jersey, London, 1999, pp [23] Robert J.K. Jacob, John J. Leggett, Brad A. Myers, et al. An Agenda for Human-Computer Interaction Research: Interaction Styles and Input/Output Devices, [24] Mulder, A. Human movement tracking technology, 1994, [25] Antifakos, S., Sensors, [26] Pawluk, D.T.V., Son, J.S., Wellman, P.S., Peine, W.J. and Howe, R.D. A Distributed Pressure Sensor For Biomechanical Measurements, Journal of Biomechanical Engineering, April, [27] Higgins, et al. Infant health monitoring system, 1996, A61B 005/020.5 USA Pat. 5,479,932 [28] Zanakis, M.F. Dynamic system for determining human physical instability, 1999, A61B 005/103, USA Pat. 5,919,150 TAUCHI MMIG G. Evreinov p 95_

[29] Teodorescu, et al. Respiration and movement monitoring system, 2000, G08B 023/00, USA Pat. 6,011,477 [30] FUKUMOTO, Masaaki, TONOMURA, Yoshinobu, "Body Coupled FingeRing": Wireless Wearable Keyboard, [31] Alternative Control Technologies: Human Factors Issues, RTO NATO, 1998, RTO-EN-3 AC/323(HFM)TP/1, ftp://ftp.rta.nato.int/PubFulltext/RTO/EN/RTO-EN-003/$$EN-003-ALL.pdf [32] Alternative Control Technologies, 1998, RTO-TR-7 AC/323(HFM)TP/3, ftp://ftp.rta.nato.int/PubFulltext/RTO/TR/RTO-TR-007/$$TR-007-ALL.PDF [33] Rekimoto J., HoloWall, [34] Rekimoto, J., GestureWrist and GesturePad: Unobtrusive Wearable Interaction Devices, [35] Jun Rekimoto, SmartSkin: An Infrastructure for Freehand Manipulation on Interactive Surfaces, CHI2002, 2002, [36] J. A. Paradiso, K. Hsiao, J. Strickon, J. Lifton, and A. Adler Sensor systems for interactive surfaces – References, [37] J. R. Smith, T. White, C. Dodge, J. Paradiso, N. Gershenfeld, and D. Allport, “Electric Field Sensing for Graphical Interfaces,” IEEE Computer Graphics and Applications 18, No. 3, 5460 (1998), [38] J. Paradiso, “The Brain Opera Technology: New Instruments and Gestural Sensors for Musical Interaction and Performance,” Journal of New Music Research 28, No. 2, 130149 (1999), [39] Aggarwal, J. K. and Cai, Q. Human Motion Analysis: A Review. In Proceedings of the IEEE Nonrigid and Articulated Motion Workshop IEEE, Piscataway, NJ, USA. TAUCHI MMIG G. Evreinov p 96_

[40] Peter J. Berkelman and Ralph L. Hollis, Magnetic Levitation Haptic Interfaces, [41] P. J. Berkelman, Z. J. Butler, and R. L. Hollis, "Design of a Hemispherical Magnetic Levitation Haptic Interface Device," 1996 ASME IMECE, Atlanta, November 17-22, 1996, DSC-Vol. 58, pp , [42] Evreinov G. Magnetic Imaging System of Virtual Objects in Haptic Space. Computer Helping People with Special Needs. ICCHP2000. Proc. of the 7th International Conference on Computer Helping People with Special Needs. July, 2000, Karlsruhe, Germany, pp [43] Clark, J. May the Force Feedback Be with You: Grappling with DirectX and DirectInput, 1998, [44] Tomi Engdal, Joysticks and other game controllers, [45] PC Game Programmer's Encyclopedia, [46] Anderson, P.H., Use of a PC Printer Port for Control and Data Acquisition, [47] Beyond Logic, (BUS & Ports) [48] Intel’s Developer Site, [49] USB Developers, [50] Universal Serial Bus Specification Revision 2.0, [51] USB-2-0.com, [52] Enhanced Host Controller Interface (EHCI) specification, [53] FLEXIBLE DISPLAYS, [54] Ferroelectric Liquid Crystal (FLC) Spatial Light Modulators (SLMs), [55] Ports’ tutorial, TAUCHI MMIG G. Evreinov p 97_

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