We have completed our final design report for the spring quarter. An electronic copy of the report can be viewed by clicking the link below. To view detailed information in regards to the group meetings please reference our "Meeting Notes" section of the web page.
View Spring Quarter Final Report
View Final Presentation Slides
Gumstix JFFS2 Filesystem Image
|
 This project is being performed by David Kesler, Dustin Grimmeissen, and Richard Anderson at the University of Cincinnati. Our advisor is Professor Philip Wilsey. The project is to create a small form factor computer that will act as a frontend in a MythTV environment. MythTV is an open source personal video recorder that operates on a client/server model. This model allows for a large backend computer to be placed away from the television set while a small frontend can be placed near the media center that only performs MPEG decoding and MythTV command interpreting. Our project is to build a frontend computer that takes up less space than a small book, while maintaining quality standards for sound, heat, and performance.
The computer we have selected to design the project on is the Gumstix connex 400xm designed by Gumstix. This board features a 400 MHz Intel XScale® PXA255 processor, 16 MB of flash space, and 64 MB of RAM. With dimensions of 80x20mm, the board is approximately the size of a stick of gum.
Along with the Gumstix motherboard, we have purhcased an expansion called the netMMC ethernet expansion board. This board connects to the 92-pin connector of the motherboard to provide an ethernet port as well as an MMC adapter. The ethernet port will be used to pass data over the network between the frontend and backend computers, and will also be used to load images to the 16 MB flash. Currently we do not plan to use the MMC adapter unless more than 16 MB is required to run the MythTV software on the Gumstix.
 A major portion of this project is to fit all of the Linux and MythTV software onto the very small space provided by the Gumstix computer. While building a Linux distribution in a small space can be performed, it may be difficult to install MythTV to this machine as well as provide the space to allow for MPEG decoding and other processing. We have chosen Gentoo Linux as the distribution that we will run our frontend system on. Gentoo provides maximal flexibility when designing operating system images and will allow us to only install the absolute necessary software for running the frontend. Using the uClibc compiler, Gentoo, MythTV, and other software programs can be compiled for placement on a tiny embedded system. This system must then be cross compiled for the ARM processor, which is the type of hardware running on the Gumstix connex board.
The final portion of our project will be to design a custom board to generate the s-video signal necessary to display the video on a television. The ARM processor outputs digital RGB information and the custom board will take this signal, downsample it, generate the necessary control signals, and pass it through two circuits. The first converts the digital RGB signals to analog RGB signals while the second generates an s-video signal based on input analog RGB values. We will also be designing IR communications so that a remote control can be used to operate the MythTV software.
|