Design And Implementation Of An Universal Infrared Remote Control System

With the introduction of the concept of smart home,more and more modern appliances are produced.The cheapest way for home appliances to be remotely controlled is through infrared.Therefore,to design a modular universal infrared remote control system,which is an intelligent,used to control a variety of household appliances,has become urgent demand.The subject has been chosen a programmable circuit,which includes data communication I/O port,infrared receiver circuit,infrared transmitter circuit,built-in storing data module,expected to achieve the purpose of functions.In the program design,it is necessary to copy 99%of the remote control code used in the market.It has practical significance to exchange effective data through the I2C communication data interface to other devices.The system can be used as a learning remote control program.Learning remote controls determined functions can be chosen necessary modules from the system for re-development.In this thesis,the basic principle of transmitted circuit and reccepted circuit has been briefly analyzed.Then the waveform of the infrared coded signal has been analyzed in detail.The significance of analysis lies in lossless reception and recovered transmittion.In order to make its main function,the basic functions of the programmable circuit are described in the view of hardware.The circuit includes memory structure,CPU core,I/O port and other common modules.These modules ensure the circuit run,communicate outside,store datas and meet other requirements.In the view of software,programming process is divided into four subroutine blocks,receiving signal subroutine,code recognition subroutine,storage subroutine and launch subroutine.Each subroutine block is designed as follows.First,infrared remote control signal is received.The receivers receive the signal to the optical and converted into different lengths of high and low level sequences.For a solution,the circuit uses the capture module to capture the carrier cycle and duty cycle,and uses the timer to record the infrared signal waveform characteristics of realtime information coding.Then the codes are processed.Special codes are identified and optimized to set the corresponding eigenvalues.Nest,the codes are stored.The circuit built-in MTP module can store code parameters,through the compression of the code parameters,in order to take only 64 bytes of storage space.Finally,the codes are transmitted.When the valid data has been read from the memory module(MTPROM),the data information of the infrared signal is extracted and restored,which extracts the information signal waveforms characteristies and restores wave.Then the built-in drive drives infrared light emitting diodes to emit infrared signals through circuit arrier signal.In general,the software system has been able to achieve the common learning.The advantages of the system used as a slave to learn infrared remote control code.Other devices finish codes transmission and receiving through the I2C communication protocol,s o as to become a module of intelligent home system.The system can also be used as a host.The infrared transmitter directly sends and receives codes.After completed the design of the system,it has been tested in detail.