Controlling 24 LEDs with just 6 pins - the Berlin Clock (Charlieplexing)

I just received back the circuit boards I ordered for two new projects, one of which I will present here: a famous street clock in Berlin. The 24 LEDs of the display are connected to the microcontroller with just 6 GPIO pins, using Charlieplexing.
en.wikipedia.o...
en.wikipedia.o...
This video is unsponsored and not monetized, as usual.
00:50 unboxing the package from pcbgogo
05:40 my previous prototype
08:00 the theory of charlieplexing
13:00 the schematics in KiCAD
14:10 importing an outline in .dxf-format
14:50 the layout in KiCAD
16:00 about the Berlin Clock (Mengenlehreuhr)
16:50 assembling the circuit board
30:15 first test of the soldered LEDs
32:00 soldering the components on the backside
35:00 connecting the board to an Arduino nano (clone)
37:00 starting a project in PlatformIO
40:00 the code for Charlieplexing
50:00 being halted by a defective USB cable
53:30 going to a higher refresh rate for a flicker free display
source code: pastebin.com/e...
circuit boards made by www.pcbgogo.com/
- 1.6 mm thick
- white solder mask, black silkscreen
- lead-free HASL
other tools used:
LED Test Tweezers www.thingivers...
TS-100 solder iron
Felder Iso-Core Clean Sn100Ni+ solder wire 0.5 mm
Arduino nano (clone), ATmega328 16 MHz, 5V
Software used:
KiCAD PCB layout www.kicad.org/
QCAD general 2D design www.qcad.org/en/
VS Code code.visualstu...
PlatformIO plugin platformio.org/

[@Some11]

Nice work and a neat led drive technique!

[@7alfatech860]

Wow, fine soldering skills!

[@uwezimmermann5427]

Thank you! It's not that difficult - you just need some practice and ok tools - but most often when failing it is not the tool which is to blame.

[@Erlandsson1964]

Comment, Comment comment ;)

[@uwezimmermann5427]

😉

[@austinfox4130]

Reply, Reply Reply ;)