Low-Level Design of Wireless Fan - Case Study Example

TABLE OF CONTENTS ii PREFACE iii I. INTRODUCTION II. THE REPORT GUIDELINES 2 A. Content 2 B. Organization and Format 2 1. Report Organization 2 2. Cover Page 2 3. Page Numbering 3 4. Page Format 3 5. Figures and Tables 3 6. Equations 4 7. Abbreviations, Symbols, and Numbers 4 8. A Reminder about Style 5 C. Acknowledgment of Materials 6 III. CONCLUSIONS AND RECOMMENDATIONS 7 REFERENCES 8 APPENDIX A. Exemplary Report Cover Page A-1 APPENDIX B. Motorola 68HC12 Specifications B-1 1. Scope 1.1 Abstract This low‐level design document is derived for a control system for a wireless fan. As such, the wireless fan allows the users to control the fan by remote. This fan has multiple levels of speed selection. This project will be developed by a microcontroller. The intended customers would be elderly people and those with special needs. The design is made with several key aspects in consideration, economical which includes the component costs, flexibility, low power consumption, and less maintenance costs. 1.2 Document Overview This document will show the layout of the low‐level design for this wireless fan. This document will also document the hardware and software which will be employed. In this document, the researcher will discuss all the components that will be on the board as well as the software of the microcontroller. The heart of the analysis will be dependent upon the IR remote Controller that involves a transmitter and a receiver circuit operation based on using infrared red rays as a medium of a wireless communication. As such, the device is used for all sorts of electronic devices like televisions air conditioners. The document is intended to capture and convey the significant design decisions which have been made in preparation for the development of the system being discussed in this document. 1.3 Terms DC: Direct Current AC: Alternating Current IR: Infrared  PIC: Peripheral Interface Controller V: Volt A: Amp (current) 2. Functional Guidelines 2.1 Required Specifications Windows PC Board connected to the computer Microcontroller to send data to the computer PIC Infrared  (IR) 2.2 Low Level Functional Overview The wireless fan should contain components and entities which will enable the system to work perfectly. After setting up the device the users will be able to relax and control the fan via the remote. The first process of the system will be the starter mechanism that is made available to the user via the buttons. When the button is pressed, the signal leads up the wire to the PIC. Once there, it is then translated via the logical inputs and given to the microchip unit through the diodes. This output signal is served to the IR LED’s through the current limitation resistors; where the electrical signal is changed to an optical signal. At this point, the motor will start. There are three additional switches which are designed to alternate between fan speeds. Sender Figure 1 Receiver Figure 2 2.3 Functional Definitions Microcontroller The microcontroller is a device that connects to the computer PC. It is incorporated into the electronic board and contains a memory, processor core, and a programmable input/output. This is therefore used to program the PIC of the remote and the receiver by use of the assembly language. PIC PIC stands for Peripheral Interface Controller. The PIC therefore works as a memory which is programmed to save and run the code for the inputs/outputs of the remote and receiver. IR Transmitter Infrared (IR) is electromagnetic radiation with wavelength between 0.7 and 300 micrometers; or roughly equivalent to the frequency range between 1 and 400 terahertz. IR receiver The IR Receiver is to receive the infrared (IR). IR receiver detects infrared light that is being projected from the transmitter. By using an infrared signal to maintain a charged capacitor, this in turn keeps the run relay ready. Motor The motor itself is the machine that converts electrical energy into mechanical ability to complete the work; for instance, the electric motors used to run multiple machines and mechanical equipment such as washing machines and air conditioners. In this way, electric motors rely on magnets to produce the electric power needed to run machinery or mechanical equipment. 3. System Design Overview 3.1 Complete Architecture The wireless device utilizes an infrared (IR) controller. This infrared (IR) serves the purpose of enhancing transmission to activate the movement of the fan. It is important to note that the switches will have an indirect link to the decoder. This is to enable to use of switches. In addition, the switches will be able to control the motor with reference to overall speed. These two components have more than a functional part. The core parts possess a physical and functional separation between the sending and receiving components. This mechanism therefore has a first infrared (IR) and a second infrared (IR) that link to transmit signals. The decoder is separated in order to send and receive signals through the system of infrared (IR). The infrared (IR) will have a relationship between the two links in a sense that the two signals shift between the objects they control. Therefore, the decoder connects to the motor that rotates to start the movement of the fan as illustrated below in figure 3. Figure 3 3.1.2 I/O Architecture For a clear way to understand the inputs and outputs see figure 4 below. Figure 1 Inputs Outputs of the Figure 2 4. Components Design 4.1 Overview The components will have two circuits the first circuit is the transmitter and the second is the receiver. In this components design it shall show each component on the both circuits and how it works. 4.2 PIC 16F883 The wireless fan system should have utilized the PIC 16f883 for both transmitter and receiver. The PIC has a 14 pin input and 14 pin outputs. It is connected to the external devices via switches for the transmitter and the IR receiver. Furthermore, the software designated frequency sort of 8 MHz to 32 kHz. As figure 4 will explain, each output and input (for example, number 1 is input for power, number 2 to 6 is input for switches to increase the speed of the fan, pin of Vdd means the positive supply voltage, pin of Vss means the negative supply voltage, pin number 26 should be the IR) have specific uses and means of conveyance. Likewise, figure 5 and 6 show an example for the pic receiver and transmitter with relation to pin 40. Figure 4 Figure 5 (transmitter) Figure 6 (receiver) 4.3 IR receiver The IR receiver connects the output IR receiver to micro electrodes. When linking future infrared with a processor, it must be set to the 4.7uF capacitor in parallel with the poles of nutrition for the future and as close as possible to those electrodes; however, this is not guaranteed to work in most cases. The following figure illustrates the circuit appropriate for this future see figure 4. In the figure below, 1 denotes the output, 2 denotes the ground, and 3 denotes Vss. Figure 7 4.4 IR Transmitter Generally, the basic building block of any infrared transmitter is revision of the information signal with the carrier signal; due to the fact that the receiver units are available and ready-made ​​for a particular carrier frequency. So it is clear that when one chooses a special IR receiver unit, one will also need to refer to a wave modulator with the same carrier frequency as that of the module IR receiver (see figure 8). The transistor and resistance is based and supplied via the infrared diode (LED). Figure 8 4.5 Motor The most important thing to set up the wireless fan is of course the motor. The motor will connect to the receiver; which in turn receives orders from the PIC. This project should require the 6v motor because the DC supply is also 6v and the diode will be 1.8v with a maximum current of 10 mA. The proposed value of resistance is 420 ohms. The ability for the resistance is 0.046 w. 5. Software Design 5.1.1 Microcontroller The microcontroller is an integrated circuit chip containing a basic unit which includes a microprocessor, memory sub-units, input and output units, and temporary processor clock to run digital analog converter and an analog-digital converter. The language that should be use in this program is assembly language. The microcontroller should control the transmitter and receiver. The program will able to control the speed of the fan and also control and the receiver to receive the signals from the LED that comes from the transmitter. Resources http://www.coregravity.com http://www.wvshare.com Read More