1. Universal remote
A universal remote is a remote control that can be programmed to operate various brands of one or more types
of consumer electronics devices. Low-end universal remotes can only control a set number of devices
determined by their manufacturer, while mid- and high-end universal remotes allow the user to program in new
control codes to the remote. Many remotes sold with various electronic devices include universal remote
capabilities for other types of devices, which allow the remote to control other devices beyond the device it came
with. For example, a VCR remote may be programmed to operate various brands of televisions.
Most universal remotes share a number of basic design elements:
 A power button, as well as a switch or series of buttons to select which device the remote is controlling at
the moment. A typical selection includes TV, VCR, DVD, and CBL/SAT, along with other devices that
sometimes include DVRs, audio equipment or home automation devices.
 Channel and volume up/down selectors (sometimes marked with + and - signs).
 A numeric keypad for entering channel numbers and some other purposes such as time and date entry.
 A set button (sometimes recessed to avoid accidental pressing) to allow selection of a particular set of
codes (usually entered on the keypad). Most remotes also allow the user to cycle through the list of
available codes to find one that matches the device to be controlled.
 Most but not all universal remotes include one or more D-pads for navigating menus on DVD players and
cable/satellite boxes.
Certain highly reduced designs such as the TV-B-Gone or keychain-sized remotes include only a few buttons,
such as power and channel/volume selectors.
Higher-end remotes have numerous other features:
 Macro programming, allowing the user to program command sequences to be sent wi th one button press
 LCD to display status information.
 Programmable soft keys, allowing user-defined functions and macros
 Aliases or "punch through", which allow multiple devices to be accessed without changing device modes (for
example, using the TV's volume control while the remote is still in DVD-player mode.)
 IR code learning, allowing the remote to be programmed to control new devices not already in its code list
 PC configuration, allowing the remote to be connected to a computer for easy setup
 Some universal remotes have the ability to also make phone calls replacing your home phone in that room.
 Repeaters are available that can extend the range of a remote control; some remotes are designed to
communicate with a dedicated repeater over RF, removing the line-of-sight requirement of IR repeaters,
while others accept infrared signals from any remote and transmit them to the device being controlled. (The
latter are sometimes built as hobby projects and are widely available in kit form.)
 Some devices, such as some computers and game consoles, use Bluetooth or a similar RF protocol rather
than infrared as the main transmission form; universal remotes compatible with those designs are available
Source of the data is: http://en.wikipedia.org/wiki/Universal_remote