In this video we're going to review the pointing devices Pointing devices are, along with the keyboard, one of the most popular input peripherals. They are fundamental in graphical user interfaces, since we need to move the on a two-dimensional environment: the screen. The most popular one is the mouse. The mouses we buy today are optical and they recognise the displacement over a surface and its speed using a light beam. Most of them have two or three buttons and a scrolling wheel, something that the most advanced ones have substituted by a multi- tactile surface on their top. You can find wired and wireless mouses. First cabled mouses used the or apple desktop bus to connect to the , but nowadays most of them use an USB port. Wireless mouses, as keyboards, can be connected to the computer using proprietary RF technology, the bluetooth standard (that also uses radio waves) or infrared technology. Infrared has the inconvenience of needing a free line of sight path to work.

There are ergonomic mouses to provide optimum comfort and avoid injuries such as carpal tunnel syndrome, arthritis and other repetitive strain injuries. They are designed to fit natural hand position and movements. You can also find gyroscopic mouses that don’t need a table, as they detect the movements of the user. The is similar to the old, mechanical mice, but upside down. The user moves the ball with the fingers (thumb or index, depending on the ball position) and press the buttons like in a ordinary mouse. Another common device is the pointing stick. It is used mainly in some and consists of an small stick situated in the middle of the keyboard that moves in four directions (up, down, right and left), But the most common device for laptops is the . It is a tactile panel that follows the movement of the finger over its surface. The modern ones detect more than one point of pressure and basic gestures can be associated to different actions, such as zoom or scroll. Besides, some other pointing devices with specific purpose can be found in the market. The is one of them, normally associated to games. It can be used in other applications, as in industry, for instance, to control machinery or robots.

There are other gaming devices that are not strictly pointing devices, as steering wheels, pedals, dancing pads or game pads, among others. Graphic tablets are similar to . The main difference is that we need a special pencil to interact. Besides, they detect different pressure levels (more than one thousand, just the basic ones), so many different writing instruments can be emulated. They are a basic tool for digital artists and designers.

There are also digital pens that don’t need a tablet. They can act as a mouse, pointing and clicking, or they can be used as pencils detecting different pressure levels. Some of them have memory to be able to work away from the computer, transfer the result later and incorporate optical character recognition software (OCR) to convert the hand made writing into digital text. And finally, we have the touch screen, used in tables and smartphones. We can consider it as a combination of a screen and a transparent touchpad, what makes it an input and .

It is normally used with the fingers and is able to recognise several touching points at the same time in what is called multitouch. This enables tablets to recognise several gestures and assign them to different commands.

They can also be used with special pens that transform the tablet into a drawing board.