Design Project - Purdue University



Homework 5: Theory of Operation and Hardware Design Narrative Team Code Name: Home Enhancement Suite Group No. 10 Team Member Completing This Homework: Will Bouchonnet E-mail Address of Team Member: wbouchon@ purdue.eduEvaluation:SCOREDESCRIPTION10Excellent – among the best papers submitted for this assignment. Very few corrections needed for version submitted in Final Report.9Very good – all requirements aptly met. Minor additions/corrections needed for version submitted in Final Report.8Good – all requirements considered and addressed. Several noteworthy additions/corrections needed for version submitted in Final Report.7Average – all requirements basically met, but some revisions in content should be made for the version submitted in the Final Report.6Marginal – all requirements met at a nominal level. Significant revisions in content should be made for the version submitted in the Final Report.*Below the passing threshold – major revisions required to meet report requirements at a nominal level. Revise and resubmit.* Resubmissions are due within one week of the date of return, and will be awarded a score of “6” provided all report requirements have been met at a nominal ments:Comments from the grader will be inserted hereIntroductionThe Home Enhancement Suite is a system that allows the average home user to easily and cost effectively set up an autonomous living arrangement. The Suite will be able to control lighting, an HDMI-CEC device such as TV or DVD player, and electronic door lock. The user will have an individual user profile that is configured via a web based application and saved for their specific RFID card. There will be three RFID card readers where the user can activate the system as they enter or leave the room or building. The system will wireless interface with the readers and connect to peripherals through various connectors (HDMI, RJ-11, RJ-45). These peripherals all have certain protocols that will be used to make the setup and function of the Home Enhancement Suite as simple for the user as possible. The end goal of the project is to make the system expandable to larger spaces and create a completely autonomous home. Theory of OperationThe Suite will consist of three different subsystems; the power supply, the RFID card readers, and a main control box that connects to the various peripherals. The power supply will connect to AC power from the wall and using a transformer, bridge rectifier, and several voltage regulators drop the voltage down to 12V/5V/3.3V for use in various subsystems in the project. Coupling capacitors and HF noise capacitor are added as per the data sheet. The main control unit uses a PIC32 microcontroller to process information coming in and takes action accordingly. The operating voltage is 3.3V and maximum of 300mA. It has a large variety of peripherals that are discussed in section 3.0. The X-10 protocol will be used to control the lighting by sending control signals through the power lines. The microcontroller interfaces with a PLIX (Power Line Interface for X-10) chip through an SPI connection. The PLIX chip operates on 5V and requires an external 8 MHz crystal and a couple resistors and capacitors [1]. The data is sent out over a RJ-11 jack to a TW523 module that plugs into the wall and sends and receives the necessary signals through the power lines. Several HDMI-CEC enabled devices will be controlled through the CEC protocol. It operates at 3.3V level logic and pulls power from an appliance, normally the TV [2]. The signal will be sent out over a one wire bus through a CEC PHY chip. There will only be one HDMI connector on the main control unit, but it has the capability to control up to 10 CEC enabled devices that are connected to one another.A LCD on the main control unit will display the active user and other information to the user. A simple 16x2 line white-on-black display operates on 3.3V and communicates via SPI from a PIC16 located onboard with the LCD. A three pin connector will connect the LCD to the main PCB. A small ambient light sensor powered off of 3.3V will take readings and control the brightness on the LCD. The control unit connects to an electronic door lock using a 2-pin connector. The door lock requires 12V and is optically isolated from the output pin on the microcontroller. The lock is fail secure, and will remain in the current state in case of a power failure.The last section within the main control unit is the Ethernet port and Xbee wireless module. The PIC32 supports Ethernet via the use of an external physical layer chip. It communicates over UART at 10/100 Mbps and uses a standard RJ-45 to connect to a network. It will allow our computer program to save the user data on the micro and then be accessed when that user swipes in. The Xbee module communicates via 802.15.4 protocol, operates at 3.3V and runs at 2.4GHz [3]. Its purpose is to communicate with the other Xbee modules in the RFID readers and receive/transmit the specific RFID swiped and check if it was valid. The module requires a UART line on the micro to initiate the data transfer. Power consumption is manageable when transmitting and minimal (<1mW) when in sleep mode. The final subsystem is the wireless RFID readers. They will be battery powered and contain the same Xbee wireless module and an ID-12 RFID chip. The ID-12 is powered off of 5V and will have a switch mode regulator. The power will be stepped down to 3.3V for the Xbee module. The RFID chip will control a transistor to light a LED and buzzer for when a correct/incorrect card swipe has been made. The transmission line will connect to the wireless module and sent the data back to the micro controller to be processed. Additionally, programming and debug headers, debugging switches, extra pin headers, and extra LEDs were implemented for ease and use when debugging the entire circuit. Hardware Design NarrativeWe are using many of the subsystems such as ADC, SPI, UART, and GPIO. The ambient light sensor will go to AN0 for ADC conversion and adjust the brightness of the LCD. UART port 1 is used for the Xbee wireless module and UART 2 for the RFID reader that is located within the main control unit. The SPI1 will be used to send signals to the LCD. SPI2 sends data to the PLIX controller for lighting control. The microcontroller has built in Ethernet capabilities and with the use of an external physical layer chip it will use that port for communication with the web server. Finally several switches and LEDs as well as HDMI-CEC bus will be controlled via GPIO. PortE will control the switches and LEDs for debugging, and PortG will have the HDMI output. Programming and debug headers are connected their respective pins as specified in the datasheet. Extra and special pins that might be needed for testing were also pinned out to a row of headers. SummaryThe Home Enhancement Suite will offer home automation by interfacing with various protocols to control lighting, an HDMI device, and an electronic door lock. The microcontroller will utilize UART, SPI, ADC and GPIO to control this variety of devices. An LCD on the main control unit will display the current user and adjust brightness based on the ambient light sensor. Two external wireless RFID readers were designed using ID-12 to read the RFID card and an Xbee wireless module to transmit the card number back to the main control unit. These modules are battery powered and will beep and light up when an accepted/rejected card is present. The whole system should be easy to set up and will create an autonomous home. List of ReferencesMicromint chips, “Power Line Interface for X-10,” Serial PLIX? datasheet, 2000. [Online]. Available: . [Accessed Feb. 15, 2012].Quantum Data, “Designing CEC into your next HDMI protocol,” , 2005. [Online]. Available: . [Accessed Feb. 15, 2012]. Digi International, “Xbee/Xbee Pro RF Modules,” Xbee wireless Modules datasheet, Sept. 23, 2009. [Online]. Available: . [Accessed Feb. 15, 2012].Appendix A: System Block Diagramlefttop00 ................
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