STC32 Eight-Sided Exquisite Development Board

This development board is based on the STC32G design, referencing the official "Dragon Slayer" development board.
Board resources include:
all I/O ports are brought
out, 49 onboard LEDs , 8 DS18B20 LEDs, and
a reserved I²C OLED screen interface (an SPI interface was omitted due to my OCD; for compatibility, one wouldn't be centered...). No CAN interface chip is included, but all I/O ports are brought out; if you need CAN functionality, purchase a CAN module. It supports STC USB hardware download and all USB-to-TTL serial downloaders (verified, but USB hardware download only works correctly when switched to 3.3V; the reason is unknown. USB TTL works normally with both 5V and 3.3V).     I'm a farmer in my 30s, so I can't dedicate all my time and energy to this; I only have time to work on it during the off-season. Since it's all self-taught, errors are inevitable. I welcome corrections from experienced developers! Front view of the board (the 5V and 3V3 silkscreen markings are reversed; the open-source PCB has corrected this). Back view of the board (the TTL interface silkscreen markings were forgotten; the open-source PCB has them). 48 I/O LED test, OLED test , WS2812B test (requires switching to 5V).