Design Of In-door Air-conditioning System Based On PIC18F4550

With the development of air-conditioner industry, the control technique of the air-conditioner also takes place huge variety. From the single speed air-conditioner to the air-conditioner whose frequency can be converted automatically, the renewal of each generation product can cause a kind of new control technique's revolution in the controlling of air-conditioner.This thesis proposes a suit of control scheme for indoor-system of air-conditioner. Each functional module of air-conditioner is the major controlled object in this design. This design carries out the signal receiving of remote device, the controlling of PG motor and stepping motor, the collection of temperature, the asynchronous communication, the display of LCD and so on.In the design of indoor-system, we use PIC18F4550 which is produced by Microchip company as its core. It is developed in terms of the characters of both the hardware and the software involved. PIC18F4550 is a kind of 8 bits MCU which has strong function and includes enhanced flash and the technology of nanowatt. There are four timers embed in it. It also has three external interrupts, two capture/compare/PWM(CCP) modules, one A/D module whose precision is 10 bits and a standard SCI. We realize the receiving of remote device's signals and the speed-adjustment of PG motor which is based on TRIAC with the MCU's CCP module. We also carry out the collection of temperature with the MCU's A/D conversion module. Using the MCU's EUSART module, we realize the semiduplex asynchronous communication. Under the strong support of these integrated modules, the hardware design becomes easy, the cost becomes lower and the difficulties of software design reduced. Also the engineer's work becomes easy.This thesis focuses on each unit's design of indoor-system. It gives a detailed explanation of the design of hardware and software control and provides some methods which are different form traditional ones. It also offers new method and solution for the air-conditioner's control. I wish this thesis could give some contributions to the development of technology for air-conditioning control forces.