Pointing+Devices

=__**Pointing Devices**__=

toc **__ Mechanical mice __**
This device was one with a tracking ball which allows the mouse to move in multiple directions without being restricted. The ball mouse has two freely rotating rollers. One roller detects the forward–backward motion of the mouse and other the left–right motion. Opposite the two rollers is a third one that is spring-loaded to push the ball against the other two rollers. Each roller is on the same shaft as an encoder wheel that has slotted edges. The slots interrupt infrared light beams to generate electrical pulses that represent wheel movement.

__// Advantages //__
- This mouse has little restriction on movement - This mouse has multiple buttons which makes it easy to use - This was the most popular mouse for personal computers when first released

__//Disadvantages//__
- This mouse is connected via a wire - This mouse can be broken easily - This mouse is relativly old and out of date

**__Wireless Mice__**
To transmit their input, typical cabled mice use a thin electrical cord terminating in a standard connector. Cordless mice instead transmit data via infrared radiation although many such cordless interfaces are themselves connected through the aforementioned wired serial buses.

__//Advantages//__
- This mouse is cordless which leaves it more comfortable for use - This mouse can be moved more freely - This mouse are more modern and are currently dominating the market

__//Disadvantaes//__
- This mouse needs to be charged - This mouse can be easily lost or misplaced - This mouse may require a sensor which opperates via a usb port

__**Trackball**__
A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes like an upside down mouse. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor. Large tracker balls are common at workstations for easy precision. Before the advent of the touchpad, small trackballs were common on laptops where there may be no desk space on which to run a mouse. Some small thumbballs clip onto the side of the keyboard and have integral buttons with the same function as mouse buttons.

__//Advantages//__
- This device is easy to use for first time users - This device can be useful and easy for navigating - This device gan be useful for gaming

__//Disadvantages//__
- This device is usually wired - This device is relatively out of date - This device isn't as popular as a mouse etc.

__**Joystick**__
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick.

__//Advantages//__
- Easy to use for computer gaming - Many buttons for easy commands - A joystick is that it is very easy to learn to use and they have a very simple design so they can be inexpensive.

__//Disadvantages//__
- Can be restricted to foward back left and right - Can be easily broken - May be only useful for gaming

__**Touch Pad**__
A touch pad or trackpad is a flat surface that can detect finger contact. It's a stationary pointing device, commonly used on laptop computers. At least one physical button normally comes with the touchpad, but the user can also generate a mouse click by tapping on the pad. Advanced features include pressure sensitivity and special gestures such as scrolling by moving one's finger along an edge.



__//Advantages//__
- They are small - Easy to use - They are very sensitive

__//Disadvantages//__
- They are small - Only on laptops - Not alot of movement aloud

**__Example Question__**
1.A joystick is used in a computer game. ** (a) ** Explain how data is captured using a joystick.

2.

Describe play a game.
 * two ** advantages of using a joystick instead of the keyboard to

1.

2.

_ [4] 1 (a) As the stick is moved forwards/backwards/left/right ... the movement is detected by sensors/switches ... which detect the // x //

and // y // -coordinates of the stick A sensor detects the depression of the button

The signals from the sensors are input to the computer

AD conversion may be used

[1] for each of (b) The stick can be moved in a more natural/intuitive way to control movement
 * four ** points [4]

... than continually pressing “arrow” keys on a keyboard

[1] for each of The user only needs to learn how to move a stick and press a button
 * two ** points

... compared to mastering all/most of the keys on a keyboard

[1] for each of Feedback possible via joystick
 * two ** points

… for a more realistic environment

[1] for each of [2] for each of
 * two ** points
 * two ** advantages