lcamtuf’s thing

lcamtuf’s thing explores the intricacies of modern and traditional electronics, challenges and insights from moving to a rural area, the basics and applications of electronic components, the impact of AI in understanding technology, the philosophy of effective altruism, and reflections on corporate life and technology's evolution. It blends technical tutorials with personal experiences and broader technological discussions.

Electronics Rural Living and Challenges Electronic Components and Circuits AI and Technology Effective Altruism Corporate Life Technology Evolution

The hottest Substack posts of lcamtuf’s thing

And their main takeaways

A neophyte's introduction to video

1020 implied HN points • 06 Dec 22
  1. Videos add a new dimension - time - and require different techniques like frequent cuts for good pacing and spatial continuity.
  2. For filming, consider short takes with a tripod for DIY projects, and longer takes with a wide-angle lens for family videos.
  3. Editing involves choosing soundtracks, using transitions synced to beats, mixing audio, color correction, and rendering high-quality backups.

What's in an op-amp?

816 implied HN points • 11 Feb 23
  1. An operational amplifier typically consists of a differential input stage, a voltage amplifier, and a push-pull output circuit.
  2. The behavior of a field effect transistor (FET) in amplification is distinct from that of a typical resistor due to its strong dependence on input signals and voltages.
  3. To improve op-amp circuits, components like FETs and current mirrors can be used to create a wide range of voltage drops and maintain a steady flow of current, enhancing performance.

MCU land, part 8: DMA bit-vending machines

612 implied HN points • 03 Mar 23
🕹 Technology Microcontrollers
  1. DMA controllers on microcontrollers like Cortex-M7 allow for memory transfers without CPU involvement.
  2. Building a "bit-vending machine" with DMA can streamline communication protocols for displays or other devices.
  3. Using DMA with hardware sync signals like PIODCCLK or PWM can enable precise, fast data transfers in digital circuits.

Not so fast, Mr. Fourier!

119 HN points • 12 Mar 24
🔬 Science Computing Signal Processing Mathematics Algorithms Engineering
  1. The discrete Fourier transform (DFT) is a crucial algorithm in modern computing, used for tasks like communication, image and audio processing, and data compression.
  2. DFT transforms time-domain waveforms into frequency domain readings, allowing for analysis and manipulation of signals like isolating instruments or applying effects like Auto-Tune in music.
  3. Fast Fourier Transform (FFT) optimizes DFT by reducing the number of necessary calculations, making it more efficient for large-scale applications in computing.

Now you're thinking with relays

209 HN points • 01 Nov 23
🕹 Technology Hardware Circuits Microcontrollers
  1. Building a one-bit computer with an ALU is possible and can simplify circuitry.
  2. Relays are well-suited for building digital logic due to their binary operation and signal amplification.
  3. Implementing arithmetic operations like addition, subtraction, multiplication, and division using relays is feasible but requires thoughtful circuit design.
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Signal reflections in electronic circuits

185 HN points • 25 Nov 23
🕹 Technology Electronics Circuits
  1. Signal reflections in electronic circuits can cause echoes of previously-transmitted signals due to impedance discontinuities.
  2. Electronic signals do not propagate through wires instantly, but travel at high speeds, around 80% of the speed of light in vacuum.
  3. Matching the characteristic impedance of the transmission line to the transmitter helps avoid issues with signal reflections in high-speed digital electronics.

The asymmetry of nudges

103 HN points • 24 Feb 24
🕹 Technology Big Tech API Browser Extensions Privacy
  1. It's common to blame big businesses for unethical practices, but often founders and CEOs are genuinely trying to do the right thing.
  2. The development of Manifest V3 in Google Chrome, though controversial, aimed to address major security and privacy risks posed by browser extensions.
  3. The concept of the asymmetry of nudges highlights how well-intentioned changes in tech companies can inadvertently limit user choices or negatively impact user experience.

The evolution of expert communities

125 HN points • 12 Nov 23
🎭️ Culture Online Communities Expertise Community Dynamics
  1. Online expert communities follow a general lifecycle model with stages of orderly growth, deluge, crackdowns, meme slope, and terminal plateau.
  2. Uncontrolled growth of online communities can lead to issues like repetitive questions, declining discussion quality, and the need for elaborate rules.
  3. As online expert communities evolve, they might face challenges like elitism, loss of meaningful discussions, and a shift towards off-topic topics.

A reactionary take on memory safety

42 HN points • 01 Mar 24
🕹 Technology Security Programming Government Software Coding
  1. Memory safety in programming languages like C and C++ is a significant issue due to the risk of buffer overflows and other coding errors.
  2. Although there is a push to adopt memory-safe languages like a mandate from The White House, the practicality and necessity of such a move is questionable.
  3. Challenges in enforcing a complete shift to memory-safe languages include the limited exposure of critical code to attacks and the fact that other security vulnerabilities are more common in causing breaches.

How do transistors work, anyway?

175 HN points • 29 Nov 22
  1. Understanding transistors is essential for grasping electronics' impact on our daily lives.
  2. Conduction in solid-state electronics hinges on electron flow and pressure equalization.
  3. Different types of transistors like JFETs, MOSFETs, and BJTs have unique characteristics and functions.

Writing at work

80 HN points • 02 Dec 22
  1. Recognize the importance of proofreading and reading text out loud for clarity.
  2. Craft a clear tagline for your writing and focus on key points to convey.
  3. Tailor your writing to your audience, prioritize clarity over complexity, and simplify sentences for better engagement.

Afternoon project: JPEG DCT text lossifizer

3 HN points • 17 Mar 24
🕹 Technology Algorithms Compression Text Analysis
  1. Using discrete cosine transform (DCT) for lossy compression can be applied to text data by converting it into frequency coefficients, quantizing them, and then reversing the process to obtain reduced-fidelity text.
  2. Mapping text data to numerical representation through a perceptual character table, rather than ASCII, can significantly improve readability even in high quantization settings.
  3. In text compression, focusing on higher-frequency components is crucial for maintaining readability, unlike image compression where higher-frequency components are reduced more aggressively.

Product security: barking up the wrong tree

2 HN points • 13 Mar 24
🕹 Technology Security Software Enterprise Coding Vulnerability
  1. The focus on product security often overshadows the more critical aspect of enterprise security.
  2. Enterprise security faces challenges like employee actions that can bypass security measures, demonstrating the need for a paradigm shift.
  3. Successful security programs accept the inevitability of compromise and prioritize detection, response, and containment over aiming for perfect defenses.

A brief history of counting machines

3 HN points • 26 Aug 23
💾 History Technology Trade Invention Development Evolution
  1. The history of counting machines dates back thousands of years, with early tools like abacus and multiplication tables.
  2. Slide rules were a significant invention in the 17th century, simplifying multiplication and division through logarithms.
  3. The evolution of calculators saw advancements like carry mechanisms and the separation of input and accumulator registers, paving the way for modern electronic calculators.

Confessions of an infosec has-been

3 HN points • 01 Dec 22
  1. Success in tech can come despite habits or beliefs.
  2. Corporate life values problem-solving and results over authority.
  3. In management, focus on nurturing leadership and fairness within the team.

You should write more

2 HN points • 06 Dec 22
  1. Writing helps clarify your thoughts and assumptions when you put them on paper.
  2. Sharing your writing can help others discover new interests and improve their skills.
  3. You don't have to be an expert to write about what excites you; knowledge transfer is about refining and expanding on existing ideas.