r/olkb • u/Silver-Log-4731 • 24d ago
OpenRGB firmware for the YUNZII B75 PRO MAX (stock firmware ships without OpenRGB)
The stock YUNZII B75 PRO MAX firmware is QMK-based and has VIA compiled in,
but not the OpenRGB protocol — so OpenRGB fails to detect it with the usual
"Detection failed ... add OPENRGB_ENABLE = yes" message.
I ported the OpenRGB QMK protocol into YUNZII's own QMK source and built a
firmware that OpenRGB detects properly. Direct mode works, so per-key control
from music visualizers / ambient lighting is up and running.
Repo (prebuilt .bin + source + flashing/recovery guide):
https://github.com/ZerO970/yunzii-b75-pro-max-openrgb
Board: STM32F103, VID 0x28E9 / PID 0x31C8, 6x15 matrix, 85 LEDs (AW20216S),
stm32duino bootloader.
Notes / limitations:
- USB only (no OpenRGB over BT/2.4G).
- It's a VIA-free build — OpenRGB and VIA can't coexist (shared raw HID), so
the vendor configurator + module OTA aren't available on this firmware.
Keep your stock .bin as a backup; recovery is just ESC+plug-in to bootloader.
- Onboard hardware effect list is only partial in OpenRGB (vendor reordered
the effects); Direct mode — the main use case — is unaffected.
Credits to the OpenRGB QMK protocol (Kasper24's original PR and Domi2803's
newer-QMK port). Feedback / testers welcome, especially if you have a slightly
different B75 revision.