Left-Handed Gaming Keypad (08gamerst)

35-key left-hand gaming keypad + 1 knob · USB wired · QMK firmware · VIA

08gamerst is the CZMao left-hand gaming keypad PCB: STM32F103CBT6 (Blue Pill), 6-row × 7-column matrix keeping the left-hand block (ESC / F1–F4, `–6, the QWERT block) plus one EC11 knob at the bottom right. It comes in two versions: with two USB 2.0 HUB ports (plug in the receivers of your main keyboard and mouse and stand the pad up on a bracket) or without HUB. The knob uses virtual key positions, so both directions can be remapped independently in VIA. QMK firmware, open source, VIA-compatible.

1. Specifications

Item	Value
PCB model	08gamerst (left-hand gaming keypad)
Keys	35 keys + 1 knob
Matrix	6 rows × 7 columns (COL2ROW)
Connection	USB wired (single mode)
Port	USB Type-C (C-to-C supported)
MCU	STM32F103CBT6 (Blue Pill)
Knob	1 × EC11 encoder (A5 / A6, resolution 4)
USB HUB	Optional version with 2 × USB 2.0 HUB ports
USB VID / PID	0x4E08 / 0x4E08
Lighting	WS2812 per-key RGB @ B13, 34 LED positions
Default effect	cycle_left_right
Layers	3 (0–2)
N-key rollover	Yes, on by default (NK_TOGG toggles it)
Polling rate	1000 Hz
Firmware	QMK (open source)
Keymap tool	VIA (web)
Source code	github.com/micahyy/czm_qmk

2. Hardware / pinout (PCB design)

Function	Pin / value
Matrix rows	B4, A7, B0, B1, B10, B11
Matrix cols	B15, A8, A9, A10, A15, B3, A4
Diode direction	COL2ROW
Knob A / B	A5 / A6 (resolution 4)
WS2812 data pin	B13
Bootloader	stm32duino

2.1 Knob virtual key positions

The knob's CW / CCW map to the virtual positions VOLU / VOLD on row 5 (ENCODERS_MATRIX_MAP) — the two right-most positions of the bottom row. They have no physical switch and are editable per layer in VIA (default: volume up / down).

3. Lighting

• WS2812 per-key RGB, 34 LED positions, default effect "cycle left/right", max brightness 180.
• CapsLock indicator: LED 18 lights white while CapsLock is on.
• Layer indicator: the whole board changes color per layer — layer 1 red, 2 green, 3 blue, 4 pink, 5 yellow, 6 purple, 7 white.
• Everything can be adjusted with FN + ALT + key (below) or in the VIA Lighting tab.

4. Layers and shortcuts

3 layers (0–2):

Action	Result
Hold FN (2nd key from the left on the bottom row)	Layer 1
Hold FN and then hold ALT	Layer 2 (FN + ALT + key)

4.1 Layer 0 (default)

Row	Keys
1st	ESC, F1, F2, F3, F4, Mute
2nd	`, 1, 2, 3, 4, 5, 6
3rd	Tab, Q, W, E, R, T
4th	Caps, A, S, D, F, G
5th	LShift, Z, X, C, V, B
6th	LCtrl, FN, LAlt, Space, knob (Vol+ / Vol-)

4.2 Layer 2 (FN + ALT — lighting & maintenance)

Shortcut	Function
FN + ALT + LShift	RGB toggle (RM_TOGG)
FN + ALT + Z	Next effect (RM_NEXT)
FN + ALT + W / FN + ALT + S	Hue + (RM_HUEU)
FN + ALT + X	Hue - (RM_HUED)
FN + ALT + E / FN + ALT + D	Saturation + (RM_SATU)
FN + ALT + C	Saturation - (RM_SATD)
FN + ALT + Q / FN + ALT + F	Brightness + (RM_VALU)
FN + ALT + V	Brightness - (RM_VALD)
FN + ALT + G	Effect speed + (RM_SPDU)
FN + ALT + B	Effect speed - (RM_SPDD)
FN + ALT + Tab	NKRO toggle (on by default)
FN + ALT + ESC	Factory reset (EE_CLR)
FN + ALT + Mute	Bootloader (QK_BOOT)

Mute is the knob position or F5 depending on the soldered layout.

5. VIA

1. Connect over USB and open VIA: CN server ｜ GitHub Pages
2. Load the keyboard definition JSON in the Design tab on first use
3. Switch to Configure and remap — changes apply instantly and are stored on the keyboard
4. All 37 positions are editable; VOLU / VOLD on the bottom row are the knob

See also: Using VIA

6. Flashing

The PCB uses the stm32duino bootloader:

1. Enter bootloader (either way):
   • Shortcut: FN + ALT + Mute (QK_BOOT)
   • Or: unplug USB, hold the top-left key (ESC) and plug back in (QMK Bootmagic Lite)
2. Flash:
   • QMK Toolbox with the compiled .bin; or
   • CLI: dfu-util -a 2 -d 1EAF:0003 -D <firmware>.bin
3. Re-plug when done.

7. Building the firmware

make czmao/08gamerst:via

Prebuilt binaries: GitHub Actions artifact firmware-08gamerst.

8. FAQ

Q: VIA does not detect the board? A: Use a WebHID-capable browser (Chrome / Edge) and load the definition JSON. Also try another port or cable.

Q: The receiver plugged into the HUB does not work? A: The HUB is a plain USB 2.0 expansion and needs the keyboard's own USB composite device to be enumerated first; connect the keypad, then plug the receiver into the HUB port.

Q: The knob turns the wrong way? A: Swap the VOLU and VOLD functions in VIA.

Q: How do I reset the keymap? A: FN + ALT + ESC (EE_CLR) clears the EEPROM back to defaults.

Q: NKRO is not recognized on some machines? A: Press FN + ALT + Tab to turn NKRO off (it is on by default); some old mainboards / BIOS only support 6KRO.

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QQ group: 677654482

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📥 Firmware & source

• Firmware source (QMK): github.com/micahyy/czm_qmk (PCB path keyboards/czmao/08gamerst)
• Prebuilt firmware: GitHub Actions artifact firmware-08gamerst

See section 6 "Flashing" for flashing instructions.