MCU #13: building a graphics stack

Going from pixels to usable graphics with an ST7789 display hooked up to a generic microcontroller. | Continue reading


@lcamtuf.substack.com | 2 years ago

I'm not cheerleading for the CISA pledge

Earlier this week, the Cybersecurity & Infrastructure Security Agency (CISA) announced that 68 tech companies — notably including heavyweights such as Google and Microsoft — signed the agency’s voluntary information security pledge. The pledge compels the signatories to pursue a … | Continue reading


@lcamtuf.substack.com | 2 years ago

MCU #12: music with one bit to spare

Retrofitting waveform playback onto a single digital output pin of a microcontroller. | Continue reading


@lcamtuf.substack.com | 2 years ago

That time I built an LD_PRELOAD worm

Teenagers' hands are the devil's playthings. | Continue reading


@lcamtuf.substack.com | 2 years ago

Sir, there's a cat in your mirror dimension

Pets do the darndest things, especially if you teach them a bit of math. | Continue reading


@lcamtuf.substack.com | 2 years ago

Fractals #2: understanding Mandelbrot

The Mandelbrot fractal is known to almost all computer geeks. But where does its complexity come from? | Continue reading


@lcamtuf.substack.com | 2 years ago

You can't handle the Buddhabrot!

Exploring the little-known sibling of the world's most famous fractal. | Continue reading


@lcamtuf.substack.com | 2 years ago

The internet's knowledge problem

Easy access to information is making it more difficult to learn hard sciences at home. | Continue reading


@lcamtuf.substack.com | 2 years ago

Is the frequency domain a real place?

The discrete Fourier transform is vital to electronics, signal processing, and radio -- but we're reading too much into what it means. | Continue reading


@lcamtuf.substack.com | 2 years ago

OSS backdoors: the folly of the easy fix

Intelligence agencies and Big Tech, not hobbyists, should shoulder the responsibility for preventing the next xz-style hack. | Continue reading


@lcamtuf.substack.com | 2 years ago

Technologist vs spy: the xz backdoor debate

Well — we just witnessed one of the most daring infosec capers of my career. Here’s what we know so far: some time ago, an unknown party evidently noticed that liblzma (aka xz) — a relatively obscure open-source compression library — was a dependency of | Continue reading


@lcamtuf.substack.com | 2 years ago

An ode to freelance historians

I was born in a country that shouldn’t exist: a Central European state that couldn’t even be found on a map from 1795 to 1918, that served as the focal point of German Lebensraum between 1939 and 1945, and that was handed over to the Soviets right after the war — remaining under … | Continue reading


@lcamtuf.substack.com | 2 years ago

Radios, how do they work?

A brief introduction to antennas, superheterodyne receivers, and signal modulation schemes. | Continue reading


@lcamtuf.substack.com | 2 years ago

The myth of the sheltered mind

Online filter bubbles probably don't shape our views. Too bad. | Continue reading


@lcamtuf.substack.com | 2 years ago

Afternoon project: JPEG DCT text lossifizer

Earlier this month, I posted a gentle introduction to two pivotal frequency-domain algorithms: discrete Fourier transform (DFT) and discrete cosine transform (DCT). The first one has countless applications in signal processing, from Auto-Tune to MRI. The second one reigns supreme … | Continue reading


@lcamtuf.substack.com | 2 years ago

Product security: barking up the wrong tree

AppSec is fine. We're not paying enough attention to corporate infrastructure risks. | Continue reading


@lcamtuf.substack.com | 2 years ago

Not so fast, Mr. Fourier!

An intuitive introduction to discrete Fourier transform (DFT, FFT), discrete cosine transform (DCT), and their inverses. | Continue reading


@lcamtuf.substack.com | 2 years ago

Gemini: how did we end up here?

LLM bias is real, but it's not as meaningful as one might think. | Continue reading


@lcamtuf.substack.com | 2 years ago

A reactionary take on memory safety

How much money should be spent on a problem that's largely solved? | Continue reading


@lcamtuf.substack.com | 2 years ago

The asymmetry of nudges

Answering the age-old question: why do bad decisions happen to good companies? | Continue reading


@lcamtuf.substack.com | 2 years ago

DACs and ADCs, or there and back again

A look at how digital-to-analog and analog-to-digital converters work - from resistor ladders to delta-sigma modulation. | Continue reading


@lcamtuf.substack.com | 2 years ago

Impedance, part 2: why do LCR meters exist?

Impedance is complex, and a common workbench gadget is not quite what it seems. | Continue reading


@lcamtuf.substack.com | 2 years ago

Hell is other people: performance management at Big Tech

I spent a fair portion of my adult life working for large tech companies. In all my interactions with peers, no other topic caused as much cynicism and angst as the question of performance management — that is, the labyrinthine processes the companies follow for deciding who to f … | Continue reading


@lcamtuf.substack.com | 2 years ago

Life, the universe, and accidental Sokoban

What rural living has to do with a Japanese puzzle game from 1982, and why are so many of you unsubscribing? | Continue reading


@lcamtuf.substack.com | 2 years ago

Primer: core concepts in electronic circuits

Back to the basics: defining key concepts in electronics without breaking out a plumbing wrench. | Continue reading


@lcamtuf.substack.com | 2 years ago

Goodbye, real electronic lab kits?

The archetypal STEM toy killed by our obsession with STEM toys. | Continue reading


@lcamtuf.substack.com | 2 years ago

Resistors are out to get ya

Resistors in op-amp feedback loops tend to behave in unexpected ways. PCB ground planes come with gotchas too. | Continue reading


@lcamtuf.substack.com | 2 years ago

Signal reflections in electronic circuits

What's the deal with "signal reflections" - and do they matter in real life? | Continue reading


@lcamtuf.substack.com | 2 years ago

The evolution of expert communities

Much has been written about the usual evolution of general-interest online communities. Less attention has been paid to the dynamics of more specialized, expert-led forums — and the unique if ultimately destructive role of expertise. Over the past 25 years, I participated in doze … | Continue reading


@lcamtuf.substack.com | 2 years ago

On corporate life

There are jobs that change the world. Yours probably isn't one of them. | Continue reading


@lcamtuf.substack.com | 2 years ago

Why I'm done with Mouser Electronics

I seldom complain about online retailers. When operating at a scale, a business needs to make tough calls to keep fraudsters and unreasonable customers at bay. In this spirit, I let most small grievances slide — and if I’m fed up, I vote with my money without making a fuss. | Continue reading


@lcamtuf.substack.com | 3 years ago

The magic of DC-DC voltage conversion

Every other consumer electronic device on the market performs some form of DC voltage conversion. The reason is simple: the voltage you get out of a typical battery or a cheap wall wart is seldom right for every part of the circuit — from motors, to LCD backlights, to latest-gene … | Continue reading


@lcamtuf.substack.com | 3 years ago

Fake Books

Late last year, at the peak of the non-fungible token (NFT) craze, I purchased about a dozen highest-rated NFT books on Amazon: I did this because I wanted to publish a balanced critique of NFTs; I figured the most honest approach would to get familiar with the best-articulated a … | Continue reading


@lcamtuf.substack.com | 3 years ago