98-key high-speed USB keyboard, 8000Hz polling rate, 10 yuan main control chip

Key parameters: USB 2.0 HS protocol, 8000Hz polling rate, 250µs trigger latency, 2ms release latency.
 
The CH32V305FBP6's ports are almost fully utilized. The SPI interface is used to read button scan signals, and the UART is used to send LED data. Since the start and stop bit levels of the UART are exactly opposite to the control signals of the WS2182, an inverter was added.
 
 
Each button has a 120Ω resistor in series to eliminate signal oscillation and improve signal quality.
 
Without the resistor, the circuit would ring due to parasitic inductance/capacitance at the moment of conduction.
 
The 120Ω resistor in series significantly improves signal quality
 
and the current lighting effect. The randomly colored RGB
 
 
casing is made of 2mm thick basswood, cut and assembled. A set of 450*880mm can be directly cut, costing approximately 40 yuan.
 
 
The PCB and positioning board are fixed with 2mm double-through copper pillars and screws.
The copper pillars are M2*5 (outer diameter 3.2mm), and the screws are M2*3.
 
The USB connection uses a separate small board, fixed with a 3D-printed base
(the flying wires were damaged during debugging, please ignore them).
 
 
The main program is entirely based on the CH32 BSP, and additional lighting effects will be added later.
Current keyboard shortcuts:
Fn+Esc (long press) = Reboot to BootLoader;
 
Fn+Enter = Alt+Enter;
 
Fn+C = Calculator;
Fn+PgDn = Calculator;
 
Fn+F10 = Mute
; Fn+F11 = Volume Down;
Fn+F12 = Volume Up;
 
Fn+Home = Mute;
Fn+End = Volume Down;
Fn+PgUp = Volume Up; Fn
 
+F7 = Previous Track ;
Fn+F8 = Play/Pause;
Fn+F9 = Next Track
 
 
 
. Finally, the firmware consists of two parts: BootLoader and main program.
The BootLoader uses a virtual USB drive; dragging the main program into the virtual USB drive will upgrade the firmware. Currently, no verification has been performed; do not include non-firmware files.
 
First, use the WCH-LinkE1V3 to write LtKeyboard_Bootloader.bin to the chip.
Then, after powering on, copy LtKeyboardFW.bin to the virtual USB drive; the keyboard will automatically restart and update.