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

Top posts of the year

And their main takeaways

Goodbye, real electronic lab kits?

3499 implied HN points • 02 Dec 23
🕹 Technology Electronics Education STEM Learning
  1. Traditional electronic lab kits are disappearing, replaced by newer products like Snap Circuits
  2. The older kits offered a hands-on, educational experience with detailed schematics and components
  3. Newer products like Snap Circuits focus more on quick gratification than teaching electronics concepts

Not so fast, Mr. Fourier!

2332 implied 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.

Product security: barking up the wrong tree

2332 implied 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.

Gemini: how did we end up here?

2166 implied HN points • 02 Mar 24
🕹 Technology AI Ethics Language Models Big Tech Content Moderation
  1. The development of large language models (LLMs) like Gemini involves mechanisms like reinforcement learning from human feedback, which can lead to biases and quirky responses.
  2. Concerns arise about the use of LLMs for automated content moderation and the potential impact on historical and political education for children.
  3. The shift within Big Tech towards paternalistic content moderation reflects a move away from the libertarian culture predominant until the mid-2010s, highlighting evolving perspectives on regulating information online.
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Resistors are out to get ya

2166 implied HN points • 28 Nov 23
🔬 Science Electronics Components Circuits
  1. Some components in electronics, like resistors, may not behave exactly as expected especially at high frequencies.
  2. Parasitic impedance and capacitance in resistors can affect circuit performance, especially in applications like feedback loops for operational amplifiers.
  3. Using a two-stage amplifier can help mitigate issues caused by resistor parasitics and ensure better signal integrity.

Energy in electronic circuits

1833 implied HN points • 16 Oct 23
🔬 Science Physics Electronics Energy Circuits
  1. Designing electronic circuits has become more stringent over the years due to advancements in technology.
  2. Understanding how energy travels through electronic circuits is crucial for circuit stability and efficiency.
  3. High-speed signals in electronic circuits can lead to significant energy expenditure and signal integrity issues.

DACs and ADCs, or there and back again

1499 implied HN points • 19 Feb 24
🕹 Technology Electronics Microcontrollers
  1. Digital circuits often require digital-to-analog and analog-to-digital converters to interface with the physical world.
  2. For digital-to-analog conversion, architectures like binary-weighted DACs and R-2R DACs are commonly used, but the latter addresses practical issues with resistor values.
  3. Analog-to-digital converters (ADCs) can be complex, involving methods like flash ADCs and slope-based ADCs, which use principles like comparison, integration, and sigma-delta modulation for accurate voltage readings.

MCU land, part 9: ST7789, the final frontier

1499 implied HN points • 09 Sep 23
🕹 Technology Microcontrollers Graphics Programming Electronics
  1. Driving a 2.8" 240x320 IPS panel with a Microchip SAM S70 Cortex-M7 MCU can be surprisingly simple.
  2. The steps to set up the ST7789 display controller involve minimal and straightforward commands like hardware reset and configuration for color mode.
  3. Generating image data for the display in 16 bpp RGB565 color mode is achievable through tools like ImageMagick.

The asymmetry of nudges

1499 implied 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.

MCU land, part 10: blocks all the way down

999 implied HN points • 20 Sep 23
🕹 Technology Graphics Audio
  1. Using a 32-bit MCU was necessary for storing graphics assets like bitmaps and ensured smooth gameplay.
  2. The display quality is not just about resolution; advancements in technology like camera sensors and display panels also play a crucial role.
  3. Game development on microcontrollers involves considerations like random number generation, handling rapid player inputs, and optimizing rotations for a smooth gameplay experience.

Hell is other people: performance management at Big Tech

282 HN points • 29 Jan 24
💼 Business Tech Companies Promotions Corporate culture
  1. Performance management at Big Tech companies can cause anxiety and stress among employees due to the focus on fairness and comparison with peers.
  2. Tech companies like Google have introduced peer-based performance evaluations to enhance fairness and transparency.
  3. Despite efforts to create more egalitarian performance management processes, the actual outcomes often involve bland feedback and reliance on managers for decisions.

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.

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 evolution of expert communities

125 HN points • 12 Nov 23
🎭️ Culture Online Communities Expertise
  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.

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.

Afternoon project: JPEG DCT text lossifizer

2 HN points • 17 Mar 24
🕹 Technology Algorithms Compression
  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.