My Portfolio

These are projects I’ve worked on either for my own edification or for class assignments.

Cosmonaut

Cosmonaut is a long-term, extremely incomplete, personal project on which I’m working, inspired by things I encounter at my day job. It began as an educational project for me to learn how to write a parser, and now aims to provide a complement to the COSMOS project by Ball Aerospace.

Currently, it can parse COSMOS definition files and create a dictionary in Rust whose members can be used to serialize a record into the bitstream that the COSMOS text defines. I wrote the bitvec crate specifically to address the fact that COSMOS definitions of wire protocols permit, and we use at work, fields that are a combination of:

  • not an even multiple of bytes in width
  • not guaranteed to start or end on a byte boundary
  • able to cross a byte boundary

These constraints are impossible to cleanly service in standard Rust, and the other bit-vector libraries I encountered did not support such manipulation. Furthermore, because I work in esoteric hardware, the endianness of bits in an element matters to the network layer, so I need to bring both bitvec and endian_trait into play in order to match the bitstream that actually transfers over the wire.

bitvec

I wrote the bitvec crate to satisfy a need I had in Cosmonaut to fill up and manage a buffer by bits instead of bytes. The other bit-vector crates I found were insufficient to my needs, and since this name wasn’t taken, I opted to write my own.

The link above goes to my more detailed article about the crate, but as a brief summary, bitvec offers:

  • control over the element type used to hold the bits (u8, u16, u32, u64)
  • extensible cursor behavior via the Endian trait, to define any ordering of bits in an element
  • comprehensive support for Rust standard traits, operators, and type properties
    • iteration
    • bit arithmetic (&, |, ^, !, <<, >>)
    • numeric arithmetic (+, -)
    • allocated type extends borrowed type, just as Vec<T> extends [T]
    • (immutable) indexing

The slice handle is two words in size and the vector handle is three words, just as the slice and vector types in the Rust stdlib.

Due to limitations of how Rust implements indexing, mutable index cannot be implemented.

Lilliput

The endian_trait crate provides a trait and a custom-derive macro to implement the trait that together enable complex structures to perform endianness-conversions of their members. This is only valid to do on aggregates of platform-independent primitives, so endian_trait only provides implementations on the Rust primitive types, and not on pointers or usize or isize. The crate also provides implementations on mutable slices over types that are endian-convertible, flipping them in place, and on small arrays (up to 256), performing a large copy. Without const generics, Rust arrays are not able to be fully targeted for generic use, so large arrays must be converted by slice.

The goals of this crate are to ease the serialization to, and deserialization from, the network for aggregate structs by performing the conversion before a serializer reads their fields. This permits decoupling of the de/serialization process from the byte ordering, so that order-agnostic de/serializers can work without issue on systems where the sender, network, and/or receiver might have byte-order mismatches.

libwyzyrdry

Nothing says “cool” like puns on an author’s name. I trust I don’t need to explain the thought process that created the above consonant salad.

There’s no such thing as an un-improveable tool, and everyone has their own personal touches to make a tool or environment truly theirs. Much as dotfiles make one’s $HOME (or %HOMEPATH%, Windows users are people too) a unique and distinctive …home, collections of programming libraries make one’s workshop.

I use the base name wyzyrdry for my personal library projects, and decorate it as each language requires.

Currently, I am only making my C and Rust libraries publicly available, as those are the only languages in which I’m actively working and have noticed needs strong enough to fill.

wyzyrdry-c

The C library is currently getting the most activity, as I use C for my day job and find its standard library extremely lacking. I will also freely confess that the items populating it are inspired by, if not directly stolen from, Rust. The Vec (growable array) and Slice (pointer/length tuple) are absolute plagiarism.

I am also writing Str (length-prefixed variable length array) and RingBuf components, which are taken directly from work projects and will be wheels I do not wish to reinvent after this.

wyzyrdry-rs

The Rust library doesn’t have much, but I’ve found that macros for early exit and for printing to stderr instead of stdout are invaluable for my uses. So I wrote an alert! and alertln! macro that functions identically to print! and println!, but targeting stderr, and an exit! macro that supports custom program return values and optionally printing a farewell message indicating the cause of the exit.

Senior Design

My Senior Design project is the largest and most complex project I have completed to date. The code itself is available on my GitHub profile. Our team also created a YouTube video summary of the completed vehicle. I can provide other documents such as our design specifications, presentations, and reports upon request.

I designed a robust Real-Time Operating System capable of using both scheduled and interrupt-driven tasks to drive an autonomous vehicle. I also wrote the hardware drivers for my peripherals – GPS, compass, ultrasonic sensors, and motors – and the RTOS modules which consumed them.

My software design received high marks from my professors, and the system interfaced flawlessly with the hardware. Our public demonstration was a complete success, and we were able to navigate our route fully without colliding with pedestrians or straying off of the sidewalk.

The software I engineered demonstrates my excellent grasp of the software design patterns and engineering principles requisite in any complex project.

MIPS CPU

For my Logic and Computer Design class, I implemented a 32-bit pipelined MIPS CPU in Verilog. I am not able to showcase the code from that class due to some licensing constraints. My design included features such as:

  • Five-stage pipeline with operand forwarding and stall detection
  • 32-element register file with half-cycle latency
  • ALU with replaceable arithmetic logic
    • Ripple-carry addition at first
    • Look-ahead-carry addition
    • Finally, Kogge-Stone addition
  • RAM access (we also designed the RAM banks and controllers)
  • von Neumann architecture: I was able to load and execute basic MIPS object code with my project, and support self-modifying program execution.
  • Access to peripheral devices using drivers I wrote

Light Show

Digital Systems, the precursor to Logic and Computer Design, had a final project that required me to create a complex behavior sequence in Verilog for an Altera FPGA. The project required an elaborate state machine and the construction from scratch of functionality taken for granted in higher languages. Code.

This Website

My talents and education lie primarily in architecture and engineering. I firmly believe in the importance of a broad skill set and mastery of new topics. I designed this website myself to understand design and UI concepts. I also improved my understanding of systems administration and networking by hosting it myself.

The code governing this site is available on GitHub.

Hermaeus

Hermaeus (homepage, source code, Gem page) is a scripted reddit client designed to archive posts. It operates by processing index pages and retrieving the content they reference. Hermaeus is capable of reformatting the downloaded text and storing it to disk; future goals include storing texts in SQL and NoSQL databases, and powering a website for public browsing of the archive it manages.

One of my design goals with Hermaeus is to have it be usable by non-technical people, namely, the moderators of a reddit community I frequent and for whom it was designed. Hermaeus achieves this goal with an easy-to-use launcher script.

Computer Assembly and System Administration

I built my server and desktop. Both machines run Arch Linux; the desktop also boots Windows, OpenBSD, and for a brief period OSX Yosemite. I am fully self-hosted; every service at this domain is run on a three-year-old box in my basement. By having a personal Linux server at home, I gained a wealth of additional experience for my classes and my own pursuits. One of the fruits of my labor is a personal VPN that allows me to distribute work and data across my machines. I employ this network as a transparent backup system, which has successfully kept my data intact through hardware failure.

/r/teslore CSS

I architect the stylesheet for /r/teslore. The source code for the current sheet is here; it is several years old and showing it. I am rebuilding the sheet in my spare time, but unfortunately am not at liberty to publicize any part of the code yet.

Rainbow Snake

I built a very simple Snake implementation for my C++ class, using Qt. I am not sure I still have the source or binaries anymore. This was the only project from my foundation classes that was publicly demonstrated, so I feel obliged to mention it even if I can no longer showcase it.