An adaptive morse code to RS-232 terminal unit This is a really nice project which I abandoned mostly because the technology is obsolete. People are now using sound cards to do what this does,
A miniature E-Field instrument This was a prototype to prove a circuit operational. The design was never implimented, but three of these were built and tested and the performance was exceptional.
The smallest DDS in the world? I built this little direct digital synthesizer on the AD9833 a couple of years ago just for fun. It later occurred to me that I have not seen a smaller one anywhere, so I thought I'd put it on the web. Please contact me if you know of one that is smaller. This circuit is usable from DC to 8 MHz, but can be made to operate up to 12.5Mz . The oputput is about 600 mV, sinewave.
A PIC18F252 based microcontroller for the AD9833 DDS. The controller board features an RS232 interface that allows you to use a dumb terminal to set the frequency of the DDS to within a few millihertz.
Here is a more advanced PIC microcontroller design. It has 5 A/D channels, eight digital I/O lines, an on-board temperature sensor, the option for RS-232 or RS-422, and can be used with a wide range of microcontrollers. 16C73 is shown , but this will work well with many 16F and 18F series MCU's. 18F252 would be well suited for use in this as a data capture and I/O controller unit.
A real-time barometric altitude beacon for small rockets. Get accurate barometric altitude data at altitudes up to 24000 feet!
A simple class C, HF transmitter I built this just for fun in one evening. It worked so well I thought I would share it. It delivers 1 Watt minimum into a 50 ohm load from about 1MHz to around 5 MHz.
A MINI ITX BEOWULF CLUSTER! I've built a MINI-ITX based massively parallel cluster named PROTEUS . I have 12 nodes using VIA EPIA V8000A , 800 MHz motherboards. The little machine is running FreeBSD 4.8, and MPICH 1.2.5.2. Troubles installing and configuring Free BSD and MPICH were few. In fact, there were no major issues with either FreeBSD or MPICH.
I had no idea at the stir this thing would cause on the internet until I posted it on mini-itx.com early this year. I'm still getting email, and the number of links and postings on the net connected with this machine continues to increase. Do a web search for "mini-cluster" and see for yourself. I get the impression that there are a lot of Beowulf/HPC fans out there.
The construction is simple and inexpensive. The motherboards were stacked using threaded aluminum standoffs and then mounted on aluminum plates. Two stacks of three motherboards were assembled into each rack. Diagonal stiffeners were fabricated from aluminum angle stock to reduce flexing of the rack assembly.
The controlling node has a 160 GB ATA-133 HDD, and the computational nodes use 340 MB IBM microdrives in compact flash to IDE adapters. For file I/O, the computational nodes mount a partition on the controlling node's hard drive by means of a network file system mount point.
Each motherboard is powered by a Morex Procase 60 dc-dc converter, and the entire cluster is powered by a rather large 12VDC swithcing power supply.
With the exception of the metalwork, power wiring, and power/reset switching, everything is off the shelf.
Click here for an image of the origital 6 node configuration.
Click here to see an image of the completed 12 node cluster.
Here is an image showing the power use (60 watts) at idle for 6 nodes.
Performance (NEW! Proteus now has 14 nodes and a new network topolgy!)
Much has changed since I first built the mini cluster! The idle power consumption is now 170 Watts (for 14 nodes) with peak demand measured at 438 Watts. The machine runs cool and quiet. The original controlling nodes have 256 MB RAM , gigabit ethernet, and a 40GB ATA 100 IDE hard disk drive. The NFS server node is similarly equipped. The computational nodes have 256 MB RAM, each and boot from 340 MB IBM microdrives by means of compact flash to IDE adapters. The computational nodes share a common NFS mount point on the controlling node, for storage and to allow for a very simple MPI configuration.
Peak performance comes out to 5.2 GFLP and 10,400 MIPS with 13 computational nodes.
At present, the mini cluster has been getting some use running imaging filters on large raw data image files. The performance is good, and the machine seems to be ready for doing "real" work.
Click here for the construction details for the mini cluster.
Click here to read a HOWTO on configuring Free BSD for use on the Mini Cluster
A matlab generated mass flow model for a 300 newton second nitrous/HTPB hybrid rocket motor. The model assumes a constant oxidizer tank presure as well as a constant combustion chamber pressure . It also does not allow for tank ullage, but motors built from this data ought to produce usable thrust. The model is also steady-state and says nothing about changes in the motor's behavior over time.
Here are some MATLAB M files for a VERY simplistic model of a coil gun that is powered by a bank of storage capacitors. This model illustrates why coil guns have a limited velocity and are grossly inefficient. It also suggests a simple means of improving the efficiency of coil guns. See if you can figure out how and why. This model consists of two files;SETUP.TXT and COIL.TXT.
Links to some of my older projects:
GOOEY An MS-DOS graphical user interface. This program has found it's way into embedded systems, probably because of it's simplicity. Source code and full documentation are included.
DRATE A realtime rate of penetration recorder/display for geophysical and P/G exploration. Has a simple GUI that is very easy to use. It features a simple, easy to construct hardware interface. Full documentation is included. This program has proven to be quite useful for directional drilling, and for drilling projects that require a precise, adjustabe display.
INDEXER An archiver/html generation tool. A program which creates a web page with links to files in a directory tree. This program is old, and written in an inelegant style, but what it does is extremely powerful and useful if you manage a web site with lots of downloadables . It was originally written so I could easily update a large (over 10,000 files) collection of downloadables in a sane manner without having to do tons of work. This version is written for Windows NT, running IIS.
More old stuff...
If you do a google search for my full name, it turns up a lot of information about some of my past work. CSCENE E-Zine (now defunct). I liked to write a few articles for it when I was in college.
