Writing

Droplet Capacitance Sensing

microfluidics

electronics

projects

This is a throwback to something I worked on a few years ago: the PurpleDrop digital microfluidic (DMF) device and a capacitance sensing method I designed for it that turned…

Rust static init with None

embedded

rust

Today I learned: initializing a rust static with None does NOT ensure a zero initialized variable!

2025 Book Reviews

books

With 2025 coming to a close, I’m going through the annual tradition of reflecting on, and summarizing the year. One of the things I’m reviewing is my reading log, so here’s…

Adding PDO Defaults to zencan

zencan

embedded

rust

Adding a simple feature to zencan brought up some thorny topics.

Publishing zencan crates

zencan

embedded

rust

I’ve finally published v0.0.1 of zencan to crates.io.

Building an application for the CoreMP135 using Rust and Slint

coremp135

embedded

linux

buildroot

rust

This is a followup to Creating linux images for the M5Stack CoreMP135 with Buildroot. The last post talked about using buildroot to make a linux image, and this post is…

Creating linux images for the M5Stack CoreMP135 with Buildroot

coremp135

embedded

linux

buildroot

rust

This post is about the M5Stack CoreMP135: why I like it, and a tutorial about how to use buildroot to create a linux image for it. A follow-up post describes how I create…

Building Custom Steel and Wood Furniture

furniture

projects

I recently finished building a pair of bedside tables in a stlye I’ve used a couple times before. This post is about the project and the process I used to do it.

Zencan Device Demo Video

rust

programming

embedded

zencan

Two weeks ago, I posted about a Rust CANOpen Stack I was working on. It was in a bit of a disfunctional state at the time. Since then, I’ve ported two firmware projects to…

Introducing Zencan: Easy CANOpen with Rust

rust

programming

embedded

zencan

I’ve been kicking around an idea for a while now to create a CAN bus communication stack for Rust, and now it is finally taking shape. It’s still a work-in-progress, but I’m…

Errors using RTT and WFI

rust

programming

embedded

This is for future-me, and for future internet searchers.

Using a Rust async function as a polled state machine

rust

programming

How to poll an async function manually, and then use the rust compiler as a finite-state-machine generator

The Gauss Speedway

electronics

projects

Here’s a fun toy project I finally finished this month. It’s a racetrack built with a printed circuit board, and small 3D printed magnetic cars. They just drive around the…

Acoustic Beamforming Notes

electronics

projects

DSP

Around August of 2022 I started working on an acoustic phased array. I bought some microphones, wired them up to an STM32H7 dev board, and wrote some Rust code to process…

High Voltage Amplifier

projects

electronics

An open-source design for a high-voltage amplifier based on the Apex PA88 450V opamp.

KiCad Racetrack Layout with Python Plugin

projects

kicad

In 2022, I designed a small magnet racetrack on a PCB, and to do it I had to create some python tools for programmatically adding tracks and via to the PCB design. This post…

Collecting home environmental sensor data with SDR, prometheus, and grafana

home automation

software

projects

Although I explored a design for a custom humidity and temperature sensor, here I describe the solution I ultimately ended up with and which I would recommend to anyone…

Custom Temperature and Humidity Sensor with E-ink Display

embedded

electronics

projects

home automation

In 2019 I wanted some sensors to spread around my new house, and I wanted a new project, so I designed this little sensor. It was a fun exercise controlling the e-paper…

Tapper: A flexible, packaged touch-screen kit for STM32

electronics

projects

embedded

Tapper is a general purple STM32 + touchscreen in a box with flexible IO for quick prototyping.

KiCad automated component layout via configuration file

electronics

kicad

A KiCad plugin for quick programmatic layout of components on your PCB.

Ultrasonic Acoustic Levitation

electronics

projects

After seeing some cool demos of acoustic levitation with ultrasonic sound pressure waves, I decided to build a levitator of my own.

Core Memory Part 2: 64-bit memory array

electronics

projects

I decided to build a modern version of an old-school core memory, for fun and to learn how they work. This article is about the design of the final memory array using a…

Core Memory Part 1: Ferrite Comparison

electronics

projects

Originally published: Sep 04, 2019

SVG Vector Graphics in Python

software

projects

Here’s a quick example of how to generate vector graphics using python and the svgwrite package. This can be handy if you need to diagram something structured and…

Programmatic Layout with KiCad and Python

kicad

For a very geometric/repetitive design, it may be easier to describe it with code than to place parts manually. To arrange LEDs at regular spacing around a circle, I used…

How to build a reflow toaster

I use my toaster oven pretty regularly for other things, but I actually only rarely use it for reflow. If you just want to reflow boards effectively, consider purchasing a…

Janissary: An Age of Empires II recording parser and analyzer

Janissary is a python parser for multiplayer game recordings from Age of Empires 2. It generates an HTML report with embedded React application for interactively viewing…

M5Stack ESP32 Dev Board

Despite their popularity, I’d never programmed an ESP32 until recently. So last month, when I needed a processor and dev board for a couple of projects I’m working on, I…

Toepler-Holtz Electrostatic Machine

projects

Back in May I had one of those fortuitous moments in an antique shop called “The Barn” in Santa Margarita, near Paso Robles. While there, I came across a couple old…

Nikon D90 Shutter Timing Measurement

I’ve been working on some electronics and software to do precisely timed photography setups for capturing water drops. One of the issues I encountered was that I seemed to…

Flaming Martini Photo Shoot

photography

This weekend, I made another attempt at photographing fire, and this time got much better results. I have seen some really cool burning beverage photos on flickr recently…

Melting Ice

photography

I set out to capture a cool fire and ice shot tonight. I didn’t have a lot of success with that; I think I need a better burning surface, and maybe a better fuel. However, I…

Reverse Engineering Nikon CLS Remote Flash Control

If you know me at all (or have read this blog much), you probably know that I’ve developed an interest in photography. I’m also an engineer, a good part of my job involves…