LED_Matrix_Light Box with ESP8266 & C++ Program

Today a Christmas gadget as active relationship work... ;-)

The plan was to let some runes shine through transparent filament using LEDs. This works very well in principle:
https://www.thingiverse.com/thing:6386091

Using Fusion360, I drew the symbols and cut them out from a hollow shell,
(which represents the dimensions of the LED matrix -
8×32 256 pixels. 32 horizontal pixels and 8 vertical pixels. Width: 8 cm (3.15 inches) Length: 32 cm (12.59 inches).),

I cannot attach the file here, so it can be found here:
(https://www.thingiverse.com/thing:7237863)
 

I cannot print such a large body, so I had to cut it (dovetail).
Thanks to the "INLAY", the body cannot slide apart once the structure is assembled.
Thanks to the incorporated gap, no post-processing was necessary; the parts fitted "snugly" but without air gaps.

The LED matrix is flexible, so I have provided "beams / supports" for backing / fixing the LED MATRIX.
Whether all cutouts / beams are used is up to each individual to decide.

Since the many LEDs can consume approx. 0.3W/LED, I had planned a 5V/40W power supply...
(256 *0.3W approx. max. 80W)
In practice, with the software, I only control the visible LEDs, and only in one color... This SEEMS to extremely limit the power consumption; no heating can be detected anywhere, neither on the power supply nor on the box. (Programming and testing on the PC USB port was also unproblematic...)

The software on the ESP8266 changes the color of the symbols every few minutes with a smooth transition...
I soldered this using wires to the 5V power supply of the LED matrix and the control line to D1.

I soldered a cut USB cable (red/black) to the "official" power supply of the LED matrix.

Since this compilation of zodiac signs is probably only relevant to me/us, I have also attached the Fusion file. It is not my most elegant design, but it obviously worked...

Parts list:
WS2812ECO 8×32 256 Pixel LED-Matrix RGB-Alloy Wires 5050 SMD individually addressable
(https://www.amazon.de/gp/product/B088K1KDW5)

D1-Mini:
e.g.  D1 ESP8266 Mini Board NodeMCU WiFi ESP8266-12F
(https://www.amazon.de/5v-ESP8266-NodeMCU-ESP8266-12F-CH340G/dp/B0D66LXTTK)

Various M3 screws

USB cable or 5V power supply

Since Markdown syntax does not (easily) support a listing, I have attached the c++ files...