Homebrew Phosphorescence Detector Looks For The Glow In Everyday Objects

Spoiler alert: almond butter isn’t phosphorescent. But powdered milk is, at least to the limit of detection of this homebrew phosphorescence detector. Why spend a bunch of time and money on s…

A Homebrew Gas Chromatograph That Won’t Bust Your Budget

Chances are good that most of us will go through life without ever having to perform gas chromatography, and if we do have the occasion to do so, it’ll likely be on a professional basis using…

A Brief Look Inside A Homebrew Digital Sampler From 1979

While we generally prefer to bring our readers as much information about a project as possible, sometimes we just have to go with what we see. That generally happens with new projects and work in p…

Arduino Measures Remaining Battery Power With Zero Components, No I/O Pin

[Trent M. Wyatt]’s CPUVolt library provides a fast way to measure voltage using no external components, and no I/O pin. It only applies to certain microcontrollers, but he provides example Ar…

Upgraded Toy Guitar Plays Music

Getting the finishing details on a Halloween costume completed is the key to impressing friends and strangers alike on the trick-or-treat rounds. Especially when it comes to things like props, thes…

Guitar Distortion With Diodes In Code, Not Hardware

Guitarists will do just about anything to get just the right sound out of their setup, including purposely introducing all manner of distortion into the signal. It seems counter-intuitive, but it w…

STM32 Oscilloscope Uses All The Features

[jgpeiro] is no slouch when it comes to building small, affordable oscilloscopes out of common microcontrollers. His most recent, based on an RP2040 with two channels that ran at 100 MSps, put it o…

A High Precision ADC That You Can Understand!

In a world where an analogue to digital converter is all too often an integrated peripheral buried inside a microcontroller, it’s easy to forget how simple these devices can be when built fro…

Audio Playback Toy For DSP Adventures

The declining costs of single-board computers has made serious computing power available for even the most trivial of tasks. It’s easy enough to slap a Raspberry Pi onto almost anything for n…

A Straightforward Old-Fashioned DAC

With modern microcontrollers, the process of interfacing with the analogue world is easy. Simply enable the on-board DAC or ADC, and talk to the world. If you’ve ever done this with a slightl…

A Pi Pico Oscilloscope

At the budget end of the oscilloscope range lie the so-called pocket ‘scopes. About the size of a deck of cards, they combine a microcontroller and an LCD screen to make an instrument with a …

Bare-Metal STM32: Adding An Analog Touch With ADCs

An Analogue to Digital Converter (ADC) is at its core a straight-forward device: by measuring an analog voltage within a set range and converting the measured level to a digital value we can use th…

Retrotechtacular: The Forgotten Vacuum Tube A/D Converters Of 1965

In any era, the story of electronics has very much been about figuring out how to make something happen with what’s available at the time. And as is often the case, the most interesting devel…

Processing Audio With The RP2040

The Raspberry Pi, although first intended as an inexpensive single-board computer for use in education, is now ubiquitous in electronics communities. Its low price as well as Linux platform and acc…

Our Favorite Things: Binary Search

You might not think that it would be possible to have a favorite optimization algorithm, but I do. And if you’re well-versed in the mathematical art of hill climbing, you might be surprised t…

Pressure Gauge Built In A Vacuum

Necessity might be the mother of all invention, but we often find that inventions around here are just as often driven by expensive off-the-shelf parts and a lack of willingness to spend top dollar…

Homebrew Circuit Explores The Mysteries Of Analog-to-Digital Conversion

When it comes to getting signals from an analog world into our computers, most of us don’t give much thought to how the hardware that does the job works. But as it turns out, there are a numb…

Finding The Right Hack Is Half The Battle

Sometimes you just get lucky. I had a project on my list for a long time, and it was one that I had been putting off for a few months now because I loathed one part of what it entailed — sens…