Author: John Elliot V

137 Articles

Piers holding a USB One ROM.

One ROM Gets A USB Stack

October 9, 2025 by 3 Comments

Our hacker [Piers Finlayson] is at it again, and this time he has added USB support to One ROM.

With this new connectivity you can attach your One ROM to your computer with a USB cable and then in a matter of seconds upload new firmware from your Chrome (or Chromium) web browser. This new connectivity will supplement but not replace the existing serial wire connectivity because the serial wire connectivity enables certain advanced use cases not supported by the USB stack, such as reprogramming a ROM in-place as it’s being served. The new USB interface will probably suit most users who just want to use One ROM to manage the ROMs for their old kit and who don’t need the extra functionality.

Addressing the question as to why he didn’t have USB connectivity from the start [Piers] claimed it was because he didn’t like soldering the USB sockets! But given this is a service he can get from his board house that is no longer his problem! [Piers] said he picked Micro USB over USB-C because the former demands less circuit board real estate than the latter. Squeezing everything on to the board remains a challenge!

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Where Is Mathematics Going? Large Language Models And Lean Proof Assistant

October 8, 2025 by 31 Comments

If you’re a hacker you may well have a passing interest in math, and if you have an interest in math you might like to hear about the direction of mathematical research. In a talk on this topic [Kevin Buzzard], professor of pure mathematics at Imperial College London, asks the question: Where is Mathematics Going?

It starts by explaining that in 2017 he had a mid-life crisis, of sorts, becoming disillusioned with the way mathematics research was being done, and he started looking to computer science for solutions.

He credits Euclid, as many do, with writing down some axioms and starting mathematics, over 2,000 years ago. From axioms came deductions, and deductions became mathematical facts, and math proceeded in this fashion. This continues to be the way mathematical research is done in mathematical departments around the world. The consequence of this is that mathematics is now incomprehensibly large. Similarly the mathematical proofs themselves are exceedingly large, he gives an example of one proof that is 10,000 pages long and still hasn’t been completely written down after having been announced more than 20 years ago.

The conclusion from this is that mathematics has become so complex that traditional methods of documenting it struggle to cope. He says that a tertiary education in mathematics aims to “get students to the 1940s”, whereas a tertiary education in computer science will expose students to the state of the art.

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ASIC physical layout

The Entire Process Of Building An Open Source Analog ASIC

October 8, 2025 by 6 Comments

Our hacker [Pat Deegan] of Psychogenic Technologies shows us the entire process of designing an analog ASIC. An ASIC is of course an Application-Specific Integrated Circuit, which is basically just custom hardware. That’s right, “just” custom hardware.

Services such as those from Tiny Tapeout make it possible to get your hardware designs built. And tools such as those found in Tiny Tapeout Analog Design VM with Skywater 130 PDK make it possible to get your hardware designs… designed.

In the video [Pat] takes you through using xschem (for schematic capture) and magic (for physical layout) to design a custom ADC. We learn that when it comes to hardware you have the choice of many different types of FETs, and not much else. Capacitors are expensive and to be avoided. Inductors are verboten. Getting specific values for things (such as resistors) is pretty much impossible so you generally just have to hope that things come out in relative proportions.

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The site controller board

Homebrew Dam Control System Includes All The Bells And Whistles

October 8, 2025 by 26 Comments

Over on brushless.zone, we’ve come across an interesting write-up that details the construction of a dam control system. This is actually the second part, in the first, we learn that some friends purchased an old dysfunctional 80 kW dam with the intention of restoring it. One friend was in charge of the business paperwork, one friend the mechanical side of things, and the other was responsible for the electronics — you can probably guess which ones we’re interested in.

The site controller is built around a Nucleo-H753 featuring the STM32H753ZI microcontroller, which was selected due to it being the largest single-core version of the dev board available. This site controller board features a dozen output light switches, sixteen front-panel button inputs, dual 24 V PSU inputs, multiple non-isolated analog inputs, atmospheric pressure and temperature sensors, multiple analog multiplexers, a pair of SSD1309 OLED screens, and an ESP32 for internet connectivity. There’s also fiber optic TX and RX for talking to the valve controller, a trio of isolated hall-effect current sensors for measuring the generator phase current, through current transformers, four contactor outputs (a contactor is a high-current relay), a line voltage ADC, and the cherry on top — an electronic buzzer.

The valve controller has: 48 V input from either the PSU or battery, motor phase output, motor field drive output, 8 kV rated isolation relay, limit switch input, the other side of the optical fiber TX and RX for talking to the site controller board, and connectors for various purposes.

If you’re interested in seeing this dam control system being tested, checkout the video embedded below.

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Diagram of C99 designated initializers.

Tips For C Programming From Nic Barker

October 7, 2025 by 47 Comments

If you’re going to be a hacker, learning C is a rite of passage. If you don’t have much experience with C, or if your experience is out of date, you very well may benefit from hearing [Nic Barker] explain tips for C programming.

In his introduction he notes that C, invented in the 70s by Dennis Ritchie, is now more than 50 years old. This old language still appears in lists of the most popular languages, although admittedly not at the top!

He notes that the major versions of C, named for the year they were released, are: C89, C99, C11, and C23. His recommendation is C99 because it has some features he doesn’t want to live without, particularly scoped variables and initializing structs with named members using designated initializers. Also C89 is plagued with non-standard integer types, and this is fixed by stdint.h in C99. Other niceties of C99 include compound literals and // for single-line comments.

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A photo of the front-panel with a bunch of lamps and knobs.

The Making Of A Minimalist Analog Drum Machine

October 1, 2025 by 15 Comments

Our hacker [Moritz Klein] shows us how to make a minimalist analog drum machine. If you want the gory details check out the video embedded below and there is a first class write-up available as a 78 page PDF manual too. Indeed it has been a while since we have seen a project which was this well documented.

A typical drum machine will have many buttons and LEDs and is usually implemented with a microcontroller. In this project [Moritz] eschews that complexity and comes up with an analog solution using a few integrated circuits, LEDs, and buttons.

The heart of the build are the integrated circuits which include two TL074 quad op amps, a TL072 dual op amp, a CD4520 binary counter, and eight CD4015 shift registers. Fifteen switches and buttons are used along with seven LEDs. And speaking of LEDs, our hacker [Moritz] seems to have an LED schematic symbol tattooed to his hand, and we don’t know about you, but this screams credibility to us! :)

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Moondream title with man's face visible in background.

Using Moondream AI To Make Your Pi “See” Like A Human

September 23, 2025 by 9 Comments

[Jaryd] from Core Electronics shows us human-like computer vision with Moondream on the Pi 5.

Using the Moondream visual language model, which runs directly on your Raspberry Pi, and not in the cloud, you can answer questions such as “are the clothes on the line?”, “is there a package on the porch?”, “did I leave the fridge open?”, or “is the dog on the bed?” [Jaryd] compares Moondream to an alternative visual AI system, You Only Look Once (YOLO).

Processing a question with Moondream on your Pi can take anywhere from just a few moments to 90 seconds, depending on the model used and the nature of the question. Moondream comes in two varieties, based on size, one is two billion parameters and the other five hundred million parameters. The larger model is more capable and more accurate, but it has a longer processing time — the fastest possible response time coming in at about 22 to 25 seconds. The smaller model is faster, about 8 to 10 seconds, but as you might expect its results are not as good. Indeed, [Jaryd] says the answers can be infuriatingly bad.

In the write-up, [Jaryd] runs you through how to use Moonbeam on your Pi 5 and the video (embedded below) shows it in action. Fair warning though, Moondream is quite RAM intensive so you will need at least 8 GB of memory in your Pi if you want to play along.

If you’re interested in machine vision you might also like to check out Machine Vision Automates Trainspotting With Unique Full-Length Portraits.

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