A NeoPixel Driver using AVR Hardware [2]

My previous article described a driver for NeoPixel (WS2812) LED displays using the SPI peripheral on an AVR processor in conjunction with a Timer/Counter and the Configurable Custom Logic (CCL).

This article shows how to go one step further, and eliminate most of the interconnections between the pins on that circuit by taking advantage of an additional feature of recent AVR processors, the Event System:

NeoPixel Driver using the hardware peripherals and Event System in an AVR128DA28.

The article A NeoPixel Driver using AVR Hardware [1] described a program for AVR processors that created the stream of pulses needed by the NeoPixel protocol,...

Применение дешевых NFC меток NTAG213/215/216 работающих по стандарту ISO/IEC 14443A для дома и других сфер применения

Рассматриваются современные NFC метки NTAG213, NTAG215 и NTAG216 разработанные компанией NXP Semiconductors, работающие по стандарту ISO/IEC 14443-A. Эти метки очень популярны благодаря своей доступности, универсальности и совместимости с большинством NFC-считывателей, включая смартфоны. Фактор дешевизны и доступности определяет массовое распространение этих NFC-меток. Что такое NFC NFC или Near Field Communication – это технология «связи ближнего действия». Она позволяет пользователям обмениваться информацией, просто поднося устройства друг к другу на расстояние до 10 см. По сути NFC это частный случай RFID (Radio Frequency Identification) — механизма радиочастотного обмена данными, хранящимися в так называемых транспондерах или метках, который основан на стандартах ISO/IEC 18092 NFC...

Why do people keep writing about the imaginary compound Cr2Gr2Te6?

I was reading the latest issue of the journal Science, and a paper mentioned the compound Cr2Gr2Te6. For a moment, I thought my knowledge of the periodic table was slipping, since I couldn't remember the element Gr. It turns out that Gr was supposed to be Ge, germanium, but that raises two issues. First, shouldn't the peer reviewers and proofreaders at a top journal catch this error? But more curiously, it appears that this formula is a mistake that has been copied around several times.

The Science paper [1] states, "Intrinsic ferromagnetism in these materials was discovered in Cr2Gr2Te6 and CrI3 down to the bilayer...

Here be dragons: Preventing static damage, latchup, and metastability in the 386

I've been reverse-engineering the Intel 386 processor (from 1985), and I've come across some interesting circuits for the chip's input/output (I/O) pins. Since these pins communicate with the outside world, they face special dangers: static electricity and latchup can destroy the chip, while metastability can cause serious malfunctions. These I/O circuits are completely different from the logic circuits in the 386, and I've come across a previously-undescribed flip-flop circuit, so I'm venturing into uncharted territory. In this article, I take a close look at how the I/O circuitry protects the 386 from the "dragons" that can destroy it.

Name that Ware, August 2025

The Ware for August 2025 is shown below.

Thanks to Curtis Galloway for contributing this bit of nostalgia! This board has the look of one that was laid out by hand using masking tape or rubylith – back in the day before computers became affordable and powerful enough to regularly use them for making new computers. It also looks hand-soldered, instead of wave-soldered. I only ever designed a couple of boards using tape, but even today I’m still hand-soldering boards – BGAs, 0201’s and all. I do a lot less of it than I used to, but you still gotta fix...

Winner, Name that Ware July 2025

The Ware for July 2025 is a Vernier Lab Pro. While researching the ware with FETguy, we noticed that the OEM for the product is probably Inventec, which also made a line of products for TI calculators at the time. That particular OEM design team applied its design language in several products. I’ll give the prize to Jin who got the exact make and model of the board. Congrats, email me for your prize!

August Update: Note-able Tablet Updates

Hello RSS users! In this update we announce a new community manager, updates to the PineTab2 and PineNote, FreeBSD on the PinePhone Pro, a guide on upstreaming PinePhone Pro patches and a small bit for you Pinecil users.

A Quick Community Update on PinePhone Pro and What’s Next

Hey everyone! As many have noticed, the PinePhone Pro is currently out ot stock on the Pine Store. Unfortunately we have to deliver you the following news: the PinePhone Pro is officially discontinued. We were told it didn’t sell well enough to keep production going. But the good news for current owners are that spare parts will still be made for up to two years, depending on demand. Meanwhile, the trusty PinePhone (A64) is still alive and kicking, and Pine Store plans to keep it rolling for about two more years.

Candle Flame Oscillations as a Clock

Todays candles have been optimized for millenia not to flicker. But it turns out when we bundle three of them together, we can undo all of these optimizations and the resulting triplet will start to naturally oscillate. A fascinating fact is that the oscillation frequency is rather stable at ~9.9Hz as it mainly depends on gravity and diameter of the flame. 

We use a rather unusual approach based on a wire suspended in the flame, that can sense capacitance changes caused by the ionized gases in the flame, to detect this frequency and divide it down to 1Hz.

Candlelight is a...

Reverse Engineering the Raspberry Pi Zero 2W

Reverse Engineering the Raspberry Pi Zero 2W

This is not a Raspberry Pi Pico. Despite it's tiny size and castellated edges, this is actually a full Raspberry Pi Zero 2W.

Well, sorta. At Open Sauce, probably the most interesting encounter I had was with Jonathan Clark.

You see, I was on a Reverse Engineering panel at Open Sauce, but I mentioned on Twitter, I wouldn't call myself a reverse engineer, more like a 'guy who breaks things sometimes taking them apart, and learns many ways to not break things, sometimes.'