Infrared Remote And Chips Are IntroducedPeople's eyes can see the visible wavele ngth from long to short accord ing to the arrangement, in order to red, orange, yellow, green, green, blue, violet. One of the red wavelengths for 0.62 ~ 0.76 mount, Purple is 0.38 wavelength range ~ mount. Purple is shorter than the wavelength of light called ultraviolet ray, red wavele ngths of light is Ion ger tha n that of in frared light. In frared remote control is to use wavelength for 0.76 ~ 1.5 mount between the near in frared to tran sfer con trol sig nal.Com mon ly used in frared remote con trol system of gen eral poi nts transmit and receive two parts. The main component part for the launch of infrared light emitting diode. It is actually a special light emitting diode, due to its internal material differs from ordinary light emitting diode, resulting in its ends on certain voltage, it is a rather infrared light. Use of infrared light emitti ng diode the in frared wavele ngths, for 940nm appeara nee and ordin ary, just the same light emitting diode five different colors. Infrared light emitting diode gen erally have black and blue, tran spare nt three colors. Judgme nt of infrared light emitting diode and judgment method, using a millimeter to ordinary diode electric block measure of in frared light emitti ng diode, reverse resista nee. The in frared light emitti ng diode lumin esce nce efficie ncy to use special in strume nt to measure precise, and use only spare con diti ons to pull away from roughly judgme nt. Recei ving part of in frared recei ving tube is a photose nsitive diode.In actual application of it receiving diode to reverse bias, it can work normally, i.e., the infrared receiving circuit application in diode is used to reverse, higher sensitivity. Infrared receiving diode usually have two round and rectangular. Due to the power of infrared light emitting diode (or less commonly 100mW), so ir receiving diode received signals is weak, so will in crease high-ga in on es.the amplifier circuit.In common CX20106A, etc. PC1373H moon infrared receiving special amplifier circuit. In recent years both amateur or formal products, mostly using in frared recei ving head fini shed. The head of in frared recei ving product packages gen erally has two kin ds: one kind USES sheet shield ing, A kind of plastic packaging. There are three pin, namely the power is (VDD), power negative (GND) and data output (VO or OUT). Infrared receiving head foot arrangement for types varied, manufacturer's instructions. Finished the advantages of infrared receiving head is not in need of sophisticated debugg ing and shell scree n, use rise as a tran sistor, very convenient. But whe n used in the infrared receiving attention finished first carrier frequency.In frared remote com mon carrier freque ncy for 38kHz, this is tran smitted by using 455kHz Tao Zhen to decide. At the launch of crystals were integer frequency, frequency coefficients, so commonly 12, so 455kHz 宁12 hun dredth kHz 38kHz hun dredth 379,000. Some remote con trol system adopts 36kHz, 56kHz, etc. general 40kHz launched by the crystals of oscillation freque ncy to decide.In frared remote characteristic is not in flue nee the surro unding environment and does not interfere with other electric equipment. Due to its cannot pen etrate walls, so the room can use com mon household applia nee of remote control without mutual interferenee, Circuit testing is simple, as long as give n circuit connection, gen erally does not n eed any commissi oning can work, Decod ing easily, can un dertake multiple remote con trol. Because each manufacturer produces a great deal of infrared remote application-specific integrated circuit, when need press diagram so jip. Therefore, the infrared remote now in household applia nces, in door close (less tha n 10 meters) in the remote con trol is widely used.Multiple infrared remote control system of infrared emission control buttons, there are many parts general representative of different controlfunction. Whe n pressed a butt on, corresp ondin gly in the receiver with differe nt output.Receiving the output state can be roughly divided into pulse, level, self-lock ing and in terlock, data five forms. "The pulse output is accord ing to laun ch" whe n the butt on, the receiver output term in als output corresp onding "effective", a pulse width 100ms in general. "Level" refers to the output launch press butt on, the receiver output corresp onding 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 depe nd 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. "Si nee the lock" refers to launch the output of each time you press the butt on, a receiver output corresp onding cha nge, n amely origi nally a state for high level into a low level, orig in ally for low level into high level. The output power switch and mute as control etc. Sometimes also called the output form for "i nv ert". "The in terlock" 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 in put speed, etc."Data" refers to launch the output some key, use a few output form a bi nary nu mber, to represe nt differe nt 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 single-chip microcomputer or are com monly used in terface. In additi on to the above output form outside, still have a "latch" and "temporary" two forms. The so-called "latch" refers to launch the output signal of each hair, the receiver output corresponding ", "new store until you receive signals. "Temporary" output and the in troducti on of "level" output is similar.Remote dista nee (Remote Con trol effect of RF Remote Con trol dista nee)are the major factors as follows:un ched in power tran smissi on power: while dista nee, but great power con sumpti on, easy to gen erate in terfere nee.2. and receiving the receiver sensitivity, receiving, remote distanee in creased sen sitivity to improve, but easy to cause disturba nee maloperati on or abuse.3. antenna, using linear antenna, and parallel, remote distanee, but occupies a large space, in use the antenna spin, pull can in crease the remote dista nee.4. and the higher height: antenna, remote farther, but by objective eon diti ons.5. a nd stop: curre nt 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 block ing will greatly disco un ted remote dista nee, if is rein forced eon crete walls, due to the absorpti on effect eon ductor, radio waves.Con sideri ng the desig n of hardware volume small to be embedded in the remote eontrol, so we chose 20 foot single-chip chip AT89C2051. Below is the in troducti on of the fun eti on.(1)AT89C2051 internal structure and performaneeAT89C2051 is a byte flash 2K with programmable read-only memory can be erased EEPROM (low voltage, high performanee of eight CMOS microcomputer. It adopts ATMEL of high-density non-volatile storage tech no logy manu facturi ng and in dustrial sta ndard MCS - 51 in structi on set and lead. Through the comb in ati on of sin gle chip in gen eral CPL1 and flash memory, is a strong ATMEL AT89C2051 microcomputer, its application in many embedded control provides a highly flexible and low cost solutions. The compatible with 8051 AT89C2051 is CHMOS micro eontroller, the Flash memory capacity for 2KB. And CHMOS 80C51 process, have two kinds ofleisure and power sav ing operati on mode. The performa nee is as follows.5. CUP, 2KB Flash memory,Working voltage range 2.7-6V, 128KB data storage.The static working way: 0-24MH z, 15 root in put/output line.A programmable serial, 2 a 16-bit timing/counters.There is a slice of in side precisi on simulatio n comparator, 5 the in terrupt sources, 2 priority.Programmable serial UART channel, Directly LED driver output,The internal structure of AT89C2051 is shown in figure 1.Figure 1 AT89C2051 in terior structure(2)AT89C2051 chip pin and functionIn order to adapt to the requireme nt of in tellige nt in strume nt, embedded in the chip foot AT89C2051 simplified configuration, as shown in figure b. The major cha nges to: (1) the lead foot from 20 to 40 wires, (2) in creased a simulated comparator.=Diagram b AT89C2051 foot figure.AT89C2051 pin fun ctio n:1. the VCC: voltage.2. to GND.3. P1 mouth: P1 mouth is an 8-bit two-way I/O port. P1.2 ~ P1.7 mouth pin the internal resista nee provides. P1.0 and P1.1 requireme nts on the external pull-up resistors. P1.0 and P1.1 also separately as piece in side precisi on simulatio n comparator with in put (AIN0) and reversed-phase in put (AIN1). Output buffer can absorb the P1 mouth 20mA current and can directly LED display driver. Whe n P1 mouth pin in to a "1", can make its in put. Whe n the pin P1.2 ~ P1.7 as in put and external dow n, they will be for the in ternal resista nee and flow curre nt (IIL). I n flash P1 mouth duri ng the procedure and program code data recei ving calibrati on.4. P3: the P3.0 ~ P3.5 P3, P3.7 is the in ternal resista nee with seven two-way I / 0 lead. P3.6 for fixed in puts piece in side the comparator output sig nal and it as a gen eral I/O foot and in accessible. P3 mouth buffer can absorb20mA curre nt. When P3 mouth pin in to "1", they are the in ternal resista nceca n push and in put. As in put, and the low exter nal P3 mouth pin pull-up resistors and will use current (IIL) outflow. P3 mouth still used to implement the various functions, such as AT89C2051 shown in table P3 mouth still receive some for flash memory programming and calibration of program con trol sig nals.5. RST: reset in put. RST once, all into high level I/O foot will reset to "1". When the oscillator is running, continuous gives RST pin two machine cycle of high level can finish reset. Each machine cycle to 12 oscillator or clock cycle.6. XTAL1: as the oscillator amplifier in put and in verse internal clock generator in put.7. XTAL2: as the oscillator reversed-phase the amplifier's output.P3 mouth fun cti on as is show n in table 1.addresses, will not meet wrong results. The scope of data storage is OOH(7FH --whe n stack man ipulatio n), also should be no ticed.The in put sig nal is simulated by the origi nal P3.6 foot into the microcontroller, so the original P3.6 foot.Un able to exter nal use. Simulati on comparator can compare two simulation, if the size of the voltage external A D/A converter and its output as A comparator an alog in put, and by simulati ng the comparator ano ther in put voltage to be measured, through the in troduct ion of the software method can realize the A/D con versi on.8. the Flash memory AT89C2051)Provide a 2KB of si ngle-chip AT89C2051 in Flash memory chips, which allows the online program to modify or use special programming program ming.(1) F lash memory en crypti onAT89C2051 SCM has 2 encryption, can programming (P) or programming (U) to obtain different encryption functionality. Encryption functionality table as shown in table 1-1.En crypt a content erased only through chips to erase operatio n.(2) F lash memory program ming and procedures the piece in side chip AT89C2051 Flash memory program ming.Note:1. the cou nters RESET at an EPROM in side the risi ng edge, and 000H RESET to XTAL1 by foot is executed, pulse count.2. pieces of 10ms to erase PROG pulse.3. during the programming P3.1 pulled low RDY/BSY instructions.(3) A T89C2051 SCM in Flash memory chips program ming steps are as follows:1.in the seque nee is the VCC GND pin, add worki ng voltage, XTAL1 pin RESET, recei ving GND pin, other tha n the above time, wait ing for 10ms.2.In P3.2 pin RESET, heighte ning level.3.In P3.3, P3.4, P3.5, P3.7 pin; add model multilevel.4. P1.0 P1.7 -- for the 000H unit add data bytes.5. RESET to in crease the 12V activati on program ming.6. P3.2 jump to a one byte programming or encryption.7. calibration has been programming, data from 12V to RESET logic level "H" and set P3.3 P3.7 -- for the correct level, and can output data in P1 mouth.8. For the n ext addresses) in the unit XTAL1 byte program ming, a pulse, make address coun ter add 1, in mouth add program ming data.9. programmi ng and calibrati on circuit figure c, d.Figure c program ming circuit Figure d calibratio n circuit Expla nati on:(1) P3.1 duri ng programmi ng in structio ns to be low RDY/BSY,(2) single erasing the PROG 10ms need,(3) internal EEPROM address coun ter on the rising edge RESET, and 000H RESET to XTAL1 by foot pulses are executed.Along with the rapid developme nt of scie nee and tech no logy, huma n society has un derg one earth-shak ing cha nges. Make our life more colorful. I n these cha nges, the remote control tech no logy has bee n widely permeates TV aerospace, military, sports and other producti on, all aspects of life. From the broad sense, all equipped with electric locomotive facility or electrical switches, if feel some n ecessary, can con sider to improve existi ng with remote control device, the operation fixed switch to realize the remote operation of the origi nal equipme nt, stop, the variable, etc. Fun cti on.switch, for example, can be used to control the electric control switch the light switch, We design the infrared remote control system to realize the opponent switch quantity control. Infrared remote characteristic is not in flue nce the surro unding en vir onment and does not in terfere with other electric equipment. Due to its cannot penetrate walls, so the room can use com mon household applia nce of remote con trol without mutual in terfere nce, Circuit testi ng is simple, as long as give n circuit conn ecti on, gen erally does not need any commissioning can work, Decoding easily, can undertake multiple remote con trol.红外遥控人的眼睛能看到的可见光按波长从长到短排列，依次为红、橙、黄、绿、青、蓝、紫。