Keychron K8 Reverse Engineering

These are unofficial firmwares, please use at your own discretion.

Keychron K8

NOTE: This code in this repository may be outdated. Please see the SonixQMK repository for the latest Keychron firmwares.

Direct link to all Keychron firmwares folder here

---

This fork brings QMK to the Keychron K8.

If you have never touched QMK before: https://docs.qmk.fm/#/newbs. Make sure you have QMK MSYS set up.

Progress:

• QMK custom keymaps are working properly
• RGB works properly, no more flickering
• Bluetooth does not work, currently waiting for QMK to release an official Bluetooth API
• VIA does not work, currently no EEPROM support

Setup repo + dependencies

1. Clone this repository: https://github.com/SonixQMK/qmk_firmware, and make sure you are on the sn32_master branch
2. In the root of the qmk_firmware directory, run these commands:
   • git submodule add https://github.com/SonixQMK/ChibiOS-Contrib.git
   • make git-submodule
   • util/qmk_install.sh
3. You should be able to compile firmwares now:
   • Open QMK_MSYS, cd to the qmk_firmware directory root, then run these commands:
     • qmk setup (if you haven't already)
     • make keychron/k8/rgb/ansi:default

Instructions on how to flash QMK to the K8:

1. Customize your keymap and compile your firmware
   • Keymaps can be found under keyboards/keychron/k8/keymaps
   • For example, if you want a firmware for the Keychron K8 ANSI, edit the keymap.c under keyboards/keychron/k8/keymaps/ansi
   • Then run make keychron/k8/rgb/ansi:ansi in QMK_MSYS
2. Download this flashing tool and run it: https://github.com/qmk/qmk_firmware/files/5862715/SONiX_USB_MCU_ISP_Tool_V2.3.1.7-.zip
3. Click 'Load File' and select SN32F24xB on the right, then choose your *.hex QMK firmware file
4. VID - 0C45, PID - 7040
5. Put your K8 into DFU/bootloader mode:
   • Remove the spacebar and short the BOOT pin to P7 pin
   • Note: There are 5 pins on the left of the spacebar switch, BOOT and P7 are the two rightmost pins
6. Connect your K8 to your computer
7. Click 'Flash' in the Sonix flashing tool
8. Enjoy

TODO List - QMK support

• Ability to safely flash bootloader
• Ability to revert to factory firmware
• Confirm Chibios functionality
• Get QMK Working
• Get RGB working
• Get VIA working (currently no EEPROM support, which is required for VIA)
• Bluetooth functionality (currently waiting on official Bluetooth support from QMK)

Chips

• Main MCU - HFD2201KBA - appears to be based on/clone of SONIX SN32F24xB

• Bt module CYPRESS CYW20730A2KFBG

• Charge IC - TPU5000

Key Matrix & MCU

MCU-Diagram - Keyboard matrix diagram on the MCU

---	col	C0	C1	C2	C3	C4	C5	C6	C7	C8	C9	C10	C11	C12	C13	C14	C15	C16
row	pin	25	26	27	28	29	30	31	32	34	35	36	37	38	39	40	41	42
R0	64
R1	63
R2	62
R3	61
R4	60
R5	59

MCU-Diagram - LED matrix

g	b	r	---	---	---	col	C0	C1	C2	C3	C4	C5	C6	C7	C8	C9	C10	C11	C12	C13	C14	C15	C16
ch1	ch2	ch3	pin	pin	pin	pin	25	26	27	28	29	30	31	32	34	35	36	37	38	39	40	41	42
Q13	Q7	Q1	01	02	04	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---
Q14	Q8	Q2	05	06	07	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---
Q15	Q9	Q3	08	09	10	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---
Q16	Q10	Q4	11	12	13	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---
Q17	Q11	Q5	14	15	47	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---
Q18	Q12	Q6	50	49	48	---	--	--	--	--	--	--	--	--	--	--	---	---	---	---	---	---	---

MCU-Diagram - mac/win and bt/off/cable dip switches

• Bluetooth / O / Cable Mode: pin 57
• Win - Android / Mac - iOS Mode: pin 58

MCU Pinout - SN32F248BF

Bluetooth module

seems to be wired like the Blitzwolf BW-KB1(https://github.com/IslamAlam/blitzwolf-bw-kb-1)