January 2025 Update
What happened? It's 2025 already!
Welcome to the January 2025 Edition
Is it me, or does time seem to be accelerating. What was that sound - that was January flying past!
Fortunately, we’ve been on the ball and collected the interesting videos and articles that happened during the month. So, if you were still recovering from the haze of Christmas and New Year, you aren’t going to miss anything.
We’ve got 3D printer camera upgrades, firmware exploits on thermometers, fancy silk screen, adventures in AI, lasers, a long read from the Electronic Engineer and much much more!
So put your feet up, grab a tea/coffee/beverage of your choice and catch up on what happened.
Things to watch
Taking a close look at his nozzle…
Mellow Labs wants to see what’s happening at the hot end of his 3D printer. With a bit of hacking around, he’s repurposed an affordable endoscope camera. Super handy for debugging troublesome prints, and looks really cool too!
Complex KiCad silk screen
Everyone loves(?) KiCad, but it’s a PCB design tool, not a graphics tool. Atomic14 has bunch of empty space on his PCB and wants to fill it full of instructions. Follow along in this video as he shares his approach.
Flashing thermometers
Not happy with stock firmware on your thermometer? Aaron Christophel walks us through bypassing the signed firmware update on a Xiaomi thermometer. Now you can update it over the air without a USB converter.
AI light switches…
Simple Electronics asks: “My lack of coding skill sometimes gets between me and my project goals - can I use FREE LLMs to help me bring a project to life?” find out in the video if he succeeds.
Frickin' laser beams
The dream of every electronic engineer is to attach laser beams to everything be able to iterate on PCBs as fast as a 3D print - no waiting for the Board Shop to ship or paying through the nose for quick delivery. Stephen Hawes is trying to make that a reality.
The long read
We’re including the occasional longer article in the newsletter. This month The Electronic Engineer is continuing his story from the November edition. If you would like to contribute - let us know!
Vocoder journey Part II ( I got a little sidetracked )
Here I was, still falling down that rabbit hole I mentioned in the November newsletter. During my fall, I managed to hold on to some branches and catch a glimpse of the world outside my little office space…
While, in the very near future, you’ll be able to play around with your own open-source vocoder, for now, you’ll have to take my word for it: it’s really so much fun to learn what you can do with proper analysis and resampling.
I was working on my own vocoder when I stumbled upon some near real-time audio editing using a Raspberry Pi Zero. That’s right—a tiny microcontroller is capable of doing so much using an audio ring buffer.
The way it works is easy to explain. Let’s take a few milliseconds of audio, sample it, and store it in a ring buffer. When the buffer is full, it starts over—hence the name “ring buffer.” At this point, we have the latest chunk of audio stored in a buffer, and we can start applying amazing effects to it.
Imagine a write pointer moving forward at a sampling speed, pointing at the current position of the ring buffer. Now, a second pointer follows the first one but at a different speed. Let’s call this the read pointer. The result is that we can speed up or slow down our playback.
Well, yeah, there are a few things to consider: the read pointer cannot go past the write pointer and vice versa. So we need to apply some additional tricks to prevent this, but you get the idea. Once you have your audio in a buffer, you can try mixing it with other sounds or even adding an echo.
The article (along with this one) I stumbled upon describes how this works and provides a nice schematic and Arduino source code to get you started.
Let me repeat what I also wrote in my personal blog: I did not design this. It was published in PiMag, the magazine. However, I did make some changes in the choice of hardware and designed a nice PCB for it.
You can find all the info here. While you can start playing around with Arduino and sound effects, I’ll keep working on my vocoder.
At this point, I’ve made my first prototype for testing, and it has lots of potentiometers. I will assign each potentiometer to a frequency band, amplitude, mixing, etc., hoping to find the best-tuned parameters for my final design.
When I’m pleased with the result, I will make sure to publish it as open source.
Things to read
Boing boing
It’s the curse of physical switches - the dreaded bounce. Jack Ganssle tries out bunch of switches to see how badly they bounce in part 1 of this 2 part investigation. You can find part 2 where he presents a bunch of solutions here.
TinyTapeout Circuit Simulator
This is very clever - you can see the gates being activated at the same time the VGA screen is being rendered. It’s an impressive combination of WebAssembly, graphics and reverse engineering. The actual TinyTapeout project is pretty cool as well.
Find my thing
Are you jealous of those Apple guys with their “Find my…” functionality? This project taps into Apple's vast "Find My" network through OpenHaystack and Macless-Haystack, making it possible for anyone to create and track their own beacon.
Everyone likes donuts!
It’s another TinyTapeout project - I’m starting to feel like I should do one of these myself! This is pretty impressive - it renders a 3D donut and requires no memory, no sines or cosines, no square roots, no divisions, and technically, not even any multiplications. The whole thing can be rendered with just shifts and adds
Getting secrets from silicon
This article examines how passive voltage contrast (PVC) and focused ion beam (FIB) techniques can be used to extract data from supposedly secure antifuses, challenging long-held assumptions about their security.
Schrödinger’s QR Code
Regular contributors Guy Dupont and Christian Walther have been competing with each other to create crazy QR codes — depending on the angle you scan them at, they will send you to one of two different websites. How? Quantum mechanics? Witchcraft? You can see their chats here.
Closing thoughts
That’s it for the January wrap up - we hope you enjoyed the collection of videos and articles.
We’ll be keeping an eye out during February for more fun and interesting things for you to watch and read.
If you know someone who might enjoy the newsletter then please feel free to share it with them!