And now a followup on how to actually update a row of LEDs efficiently, using bitplanes:
https://aykevl.nl/2026/01/bitplanes/
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.
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.
Zu viele LED anzusteuern und zu wenige Ausgänge am Controller übrig?
#Charlieplexing kann eine Lösung sein
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
That project is a « fork » of the city clock, a binary clock from https://www.instructables.com/id/The-Binary-Clock-the-City-Clock/ [https://www.instructables.com/id/The-Binary-Clock-the-City-Clock/] but uses an ESP8266 instead of an arduino (to sync time at startup instead of using an real time clock module).
Ayke van Laethem
Ben Clifford
Pater Practicus
DD3AH 📡📶 🏳️🌈🌐
Hazelton
Other-worldly Hugh
hackaday unofficial
Grégory PAUL