@dendrobatus_azureus

A binary clock only needs 9 leds. With multiplexing, that's just 6 leads. With #Charlieplexing... five?

So, either an ATTiny with some kind of decoder chip, or a slightly larger ATmega chip?

Oh, maybe this!!! https://www.adafruit.com/product/3677
That could even drive the LEDs individually, no multiplexing!

I wish I was better at #soldering. It low-key terrifies me. 😆

I could maybe bodge a design for a surface-mount LED board and send it to pcbway and have them a$$emble it?!? 🤷‍♂️

Adafruit ItsyBitsy 32u4 - 5V 16MHz

What's smaller than a Feather but larger than a Trinket? It's an ItsyBitsy! Small, powerful, Arduino-compatible - this microcontroller board is perfect when you want something very ...

Как я сделал брелок на ATtiny13, научил его трем гипнотическим режимам и превратил в набор для пайки

Представьте: маленький брелок лежит в кармане. На нём — мордочка кота из популярного мема. Нажимаешь кнопку на затылке — и в центре головы загорается круг из двенадцати ярких SMD-светодиодов. Два огонька начинают бегать по кругу с коротким хвостом. Ещё одно нажатие — и запускается спиннер: три луча вращаются по часовой, потом три круга против. Третий режим — маятник, три светодиода плавно качаются взад-вперёд, как загипнотизированный взгляд. Четвёртое нажатие — и всё гаснет. Батарейка CR2032 отдыхает. Всё это работает на самом дешёвом микроконтроллере ATtiny13. Четыре пина управляют двенадцатью светодиодами через Charlieplexing. Никаких Arduino, никаких сдвиговых регистров.

https://habr.com/ru/articles/1044438/

#ATtiny13 #Charlieplexing #DIY #набор_для_пайки #SMD #светодиоды #брелок #встраиваемые_системы

Как я сделал брелок на ATtiny13, научил его трем гипнотическим режимам и превратил в набор для пайки

Представьте: маленький брелок лежит в кармане. На нём — мордочка кота из популярного мема. Нажимаешь кнопку на затылке — и в центре головы загорается круг из двенадцати ярких SMD-светодиодов. Два...

Хабр

And now a followup on how to actually update a row of LEDs efficiently, using bitplanes:
https://aykevl.nl/2026/01/bitplanes/

#EmbeddedSoftware #firmware #hardware #leds #Charlieplexing

Binary Code Modulation

Bitbanging many LEDs from a microcontroller can be very fast, when using Binary Code Modulation and some assembly.

Charlieplexing LEDs is actually really neat, if you understand how it works. It's basically just a LED matrix where you use the same pins on both sides of the matrix. I've written about it in my latest blog post:
https://aykevl.nl/2026/01/charlieplexing/

Charlieplexing is what allows my 36-LED earrings to have so many LEDs - I would have needed a bigger microcontroller without Charlieplexing.

#Charlieplexing #led #LEDMatrix

Charlieplexing

Charlieplexing is kinda difficult to wrap your head around initially, but once you understand it, it actually makes a lot of sense. This post will try to show you how it works and why it's actually quite beautiful.

Trying to charlieplex a 10 segment bargraph with 4 different colours (and hence 4 different resistances) off 4 pins. Without using 10 resistors because I don't have that much space on this little board. Which I can almost do trivially except one of the colours is 4 bars so can't get them all through one resistor but have to share with one of the other colours...

Time to get the random number generating computer program out.

#Charlieplexing #LEDs

Thanks to some really useful tip-offs, I've been reading up on #Charlieplexing (why is it even called that?), and I think it could be ideal for my model level-crossing lights. I've got three LEDs to control (amber and 2x flashing red) and it looks like I can control all three with just two GPIO pins on my Raspberry Pi Pico. Then, one of my 'wires' can be the hollow metal pole of the sign, with the other going up the middle - which would be perfect.

Zu viele LED anzusteuern und zu wenige Ausgänge am Controller übrig?

#Charlieplexing kann eine Lösung sein

https://dd3ah.de/charlieplexing/

Charlieplexing - DD3AH

Charlieplexing senkt die Anzahl der benötigten Ausgänge zur Ansteuerung von LEDs deutlich

DD3AH
test printing a 3x3 #charlieplexing circuit, will probably pack this tighter if there's partial success.

2 days of learning charlieplexing and PIO on the rp2040 only for it to just not work and have no real indication as to why. Best guess is that maybe the LEDs aren’t all the same. I guess tomorrow I’m playing around with that PIO emulator - and therefore once again installing the JDK 😫

Also I suspect that my PIO program isn’t very good. No idea what would improve it though! #rp2040 #pico #charlieplexing #LEDs #pio

Heart-Shaped Heartwarming Valentine’s Day Pendant

This is no ordinary heart-shaped PCB pendant project! To us, it's also symbol representing the striking amount of love that [SaltyPaws] has put into its design and documentation. He tells us that he designed it for the two daughters he is raising, as an electronics and general STEAM introduction - with outstanding educational and aesthetic qualities, giving insights into a wide range of topics while looking . The PCB is mostly through-hole, making for easy soldering and quick return on the effort investment. The project is thought-out beyond the PCB, however - this pendant is designed to be wearable day-to-day, which is why it's accompanied by a 3D-printed frame, protecting its wearer from sharp PCB edges and through-hole lead ends!

Open-sourcing things is a gift, and today, we are also the recipients. [SaltyPaws] has open-sourced everything involved - PCB files, 3D cover files, firmware, BOM, everything you would need to build your own version. All of this is in a GitHub repository, with detailed sourcing and assembly instructions in the README.md - we couldn't ask for more! If you have loved ones that would take delight in putting such a pretty pendant together, you have about a week to order the PCBs - after that, Chinese New Year will likely thwart your plans!

Looking for more accessories that double as electronics projects? We've covered a wide variety, even when it comes to pendants alone - check out this edge-lit fluorescent acrylic educational Maker Faire accessory, or this circuit sculpture BEAM-inspired bird-imitating one, or this tiny SAMD21-powered pendant with an IPS LCD!

#wearablehacks #charlieplexing #pcbart #pendant #steameducation