Glossary

Terms and acronyms used across the wiki.

• VIA: usevia.app, the browser configurator used for all keymap changes (no firmware recompile).
• WebHID: the browser HID API the yunzii-game.com LCD app uses; it strips the report-ID byte.
• HID: USB Human Interface Device; the AL80 exposes 4 HID interfaces (see Hardware).
• RGB565 BE: 16-bit color, 5 bits red / 6 green / 5 blue, stored big-endian (2 bytes per pixel).
• PK_*: the display module's command set, spoken over USART3; the wire opcode equals the PK enum ordinal (see Display commit).
• PK_ADD_PIC: opcode 0x0C, commit-the-scratch-buffer-and-display. The command that actually shows a still image.
• PK_TOGGLE_PIC: opcode 0x0D, advance to the next stored picture slot (not "show this frame").
• yne: the additive checksum carried in bytes[4,5] (16-bit LE); one rule for every packet.
• DFU: Device Firmware Upgrade (bootloader) mode; entered by commands 0xB0–0xB7. Avoid, brick risk.
• NAK: a negative/non-acknowledgement response (device returns FF 00 00 … for unsupported commands).
• ACK: acknowledgement; the device echoes a packet with byte[6] = 0x55.
• CKSUM: a one-byte additive checksum carried in a packet (formulas given per packet type).
• announce / data / finish: the three packet roles in every screen operation: 0x40 / 0x41 / 0x42.
• aw20216s: the SPI LED driver chip that drives both the keys and the 3 side-bar LEDs (NOT WS2812).
• ripple: the YUNZII official v1.21 lighting firmware (bcdDevice 0x0121), the stock build in use.
• b75Pro: a sibling YUNZII board whose QMK source shares the PK_* protocol family; used as a source reference for the AL80.