An unusual demilitarized slide rule The post War and Peace appeared first on Nathan's Possibly Interesting web site.

I built a tiny piano app and found a chord that physically cannot be played on a MacBook keyboard. The bug wasn't in my code—it's soldered into the keyboard, and it's been there for sixty years.

Quick and encouraging update on last week's complaints about how hard Eurorack rails are to get right : using a template seems to have solved all my problems. I created this template , grabbed some…

In the before-times, when Raspberry Pi CM5s were (relatively) affordable, I built a number of Pi clusters (example), and one of the most annoying parts of the build was flashing Raspberry Pi OS to…

The interaction between hardware design and firmware implementation requires strict consistency in embedded systems. Firmware must exactly match the schematic-level component configuration and…

What do you mean, a clone of Akai's S56usb USB card? As often happens, it's a long story that began in the early 2000s with the purchase of an AKAI S5000. The machine seemed very interesting to me…

Well it was a good idea. I was able to combine all eight of my serial interrupt signals into one using only a 74F688 comparator and a 2N2222 transistor. It worked great! Any interrupt on any of the 8…

One of the questions I get asked most often about plug-in solar is surprisingly simple: Can I add a plug-in solar and battery system if I already have residential solar and batteries? The answer is…

A year on the Rockchip RK3588 NPU: from hacking a closed toolchain to run one vision encoder, to an open, extensible compiler and runtime that works from PyTorch, ONNX, and JAX.

OpenNPU v1.0 is an MIT-licensed compiler and runtime that runs ONNX, PyTorch, and JAX models on the Rockchip RK3588 NPU through raw DRM ioctls, with no closed-source dependency. This report covers…

Related work Baby QRO Switching RF amplifier for HF Digitally Adjustable RF PA Supply A new generation of the Baby-QRO switching amplifier targets 10 W to 500W+ of RF output for FT8 and other FSK…

Several months back I posted on the Fediverse about a wind turbine project I was working on for a university class - sharing my troubleshooting efforts as I try and power through an interesting…

There’s a thing people do on Bluesky a lot where they post “one like = one thought on [thing],” and then, well, for every like that skeet gets (yes, I am ride-or-die that they are…

Reviewing my robot builds

Embedded firmware must be resilient and recover even from impossible conditions because eventually the impossible happens. This post discusses techniques to make firmware more resilient and keep on…

Twenty-three-year-old Edwin Herbert Hall discovered the Hall effect in 1879, while working on his doctorate at Johns Hopkins University. He found that when electric current flows through a conductor…

About a year ago I made an Arduino board that worked with old MFM/RLL (“Winchester”) drives by utilizing a Western Digital controller chip. As this was limited to a particular format…

The developer says: [SDR Oxide is a] powerful SDR transceiver client with a GPU panadapter, dual VFOs, neural noise reduction, built-in skimmers, a full stack of digital modes, Winlink radio email,…

I got my Clicks Power Keyboard today and i have to admit, i am whelmed. I preordered it on a whim back in January and I am not sure what I thought (I blame the grief!). I didn’t even remember…

I am of an age that I remember well the cool stereo systems we had in the 1980's, 1990's and early 2000s. Especially I love stereo system components - Amplifier, Radio, Graphic equaliser, tape deck,…

Your next group birthday gifts should be home batteries. Most birthday gifts are forgotten within a year. Batteries save your friends money every day and keep essential devices running when the power…

Complete device takeover by blinking at it!

Touch is arguably the most human sense — and the humble button, the most misunderstood switch. A tour of touch receptors, debouncing, and a dozen ways engineers have reinvented the click.

This is a description of how I build programmable hardware. Everything that goes into Cocoapuffs, my RISC-V system-on-chip on an Artix-7 FPGA: the RTL, the firmware, the simulations, the synthesis,…

My experience fixing my Framework 13" laptop with AMD 7060 series that was bricked due to a failed BIOS update with US$20 worth of tools, instead of replacing the motherboard as suggested by…

Hacking the DC34 badge: a shared loader-jump foothold, different temporary-Xous routes for K0 and Flag1, and an IFR instruction-reconstruction extension.

Background Filters are a hotly contested topic in the realm of Meshtastic and Meshcore. Often for mesh radios, bandpass filters are the specific type of filters of primary interest. The job of these…

Background The goal of this post is to assist others with demonstrating how measure typical characteristics of a Meshtastic / Meshcore band pass filter. Equipment A few very basic pieces of test…

Check out the main review here: Product Review: LiJiANi RD-239S + W2. This post is some accumulated notes. Antenna The W2 repeater comes with a 4.2m antenna, terminated in a 3.5mm plug. The other end…

blog post: my new-ish wimpy electronic drum kit go there

More Bluetooth (hardware) shenanigans

I am often asked to explain my distaste for RISC-V. Here it is.

The Studio Display XDR is almost everything I wanted, and it has an extremely normal and reasonable connectivity situation.

A couple of months ago, I had my HVAC controller replaced in an effort to save on electricity. I controlled the previous board with an IR blaster that I loaded with a full matrix of {mode,fan_speed,…

This is a Hall effect 65% board. For what it is, it’s a real bargain. It’s aimed at gamers, and comes with an in-your-face set of flashy keycaps. Some important specs: 3.5mm travel Wired only No side…

I have targeted the following M5 Stack models with my C64/C128/Vic-20/Apple 1 emulator : M5Stack Fire IoT M5 Core2 M5 CoreS3 (Even though I have targeted other boards, I had only implemented touch on…

How I silenced the second hand of my second-hand vintage Audubon bird clock by replacing the clock movement

Vivid EV has ceased to exist, so you have to come up with clever ways to find replacement parts

Firmware update for mouSTer a universal USB HID class device to db9 adapter. mouSTer 3.23.5313: Added option for actvepotlines for Amiga mouse to support Mega65 Amiga core. (and possibly more)…

One day I was strolling through IKEA and stumbled upon VARMBLIXT wall lamp. I found the design intriguing and thought it would complement my living area perfectly. For the most part, the lamp…

Dennis (AD6DM) told me about Meshtastic before Defcon 34, so I bought 2 little radios from the merch area to try it out. If I'm being honest, what hooked me was the adorable 3d-printed tomagotchi1…

Building a wireless environment monitor with a BME680 sensor and an ESP32 running Tasmota, sending temperature, humidity and air quality data over MQTT.

low level control on a Unitree R1 EDU: making the elbow joint go up and down, and all the math that shows up on the way