【正文】 , can undertake multiple remote control. Because each manufacturer produces a great deal of infrared remote applicationspecific integrated circuit, when need press diagram suo ji. Therefore, the infrared remote now in household appliances, indoor close (less than 10 meters) in the remote control is widely used. Multiple infrared remote control system of infrared emission control buttons, there are many parts general representative of different control function. When pressed a button, correspondingly in the receiver with different output. Receiving the output state can be roughly divided into pulse, level, selflocking and interlock, data five forms. The pulse output is according to launch when the button, the receiver output terminals output corresponding effective, a pulse width 100ms in general. Level refers to the output launch press button, the receiver output corresponding output level , effective transmit to loosen the receiver level disappears. This effective pulse and effective, may be of high level is low, and may also depend on the output corresponding static state, such as feet for low, static high for effective, As for the static, low high effective. In most cases, high for effective. Since the lock refers to launch the output of each time you press the button, a receiver output corresponding change, namely originally a state for high level into a low level, originally for low level into high level. The output power switch and mute as control etc. Sometimes also called the output form for invert. The interlock refers to multiple outputs each output, at the same time only one output. The TV sets of this case is selected, the other is like the light and sound input speed, etc. Data refers to launch the output some key, use a few output form a binary Infrared Remote And Chips Are Introduced 3 number, to represent different keystroke. Normally, the receiver except a few data output, but also a valid output data, so the timely to collect data. This output form with singlechip microputer or are monly used interface. In addition to the above output form outside, still have a latch and temporary two forms. The socalled latch refers to launch the output signal of each hair, the receiver output corresponding , new store until you receive signals. Temporary output and the introduction of level output is similar. Remote distance (Remote Control effect of RF Remote Control distance) are the major factors as follows: 1, launched in power transmission power: while distance, but great power consumption, easy to generate interference, 2 and receiving the receiver sensitivity, receiving, remote distance increased sensitivity to improve, but easy to cause disturbance maloperation or abuse, 3, antenna, using linear antenna, and parallel, remote distance, but occupies a large space, in use the antenna spin, pull can increase the remote distance, 4 and the higher height: antenna, remote farther, but by objective conditions, 5 and stop: current use of wireless remote use of UHF band stipulated by the state, the propagation characteristics of approximate linear transmission, light, small, transmitters and receivers diffraction between such as walls are blocking will greatly discounted remote distance, if is reinforced concrete walls, due to the absorption effect conductor, radio waves. Considering the design of hardware volume small to be embedded in the remote control, so we chose 20 foot singlechip chip AT89C2051. Below is the introduction of the function. 1) AT89C2051 internal structure and performance AT89C2051 is a byte flash 2K with programmable readonly memory can be erased EEPROM (low voltage, high performance of eight CMOS microputer. It adopts ATMEL of highdensity nonvolatile storage technology manufacturing and industrial standard MCS 51 instruction set and lead. Through the bination of single chip in general CPL1 and flash memory, is a strong ATMEL AT89C2051 microputer, its application in many embedded control provides a highly flexible and low cost solutions. The patible with 8051 AT89C2051 is CHMOS micro controller, the Flash memory capacity for 2KB. And CHMOS 80C51 process, have two kinds of leisure and power saving operation mode. The performance is as follows: Infrared Remote And Chips Are Introduced 4 8 CUP, 2KB Flash memory, Working voltage range , 128KB data storage, The static working way: 024MHz, 15 ro