CSTC40

This keyboard has 3 known hardware revisions, please be sure to flash the correct firmware for your PCB

A 40% hotswap ortholinear RGB keyboard from KP Republic

Revision 1: "daughterboard"

• STM32F402RCT6 MCU with IS31FL3733 LED driver, using stm32-dfu bootloader. Uses a separate daughterboard for USB connection.

• Upon entering bootloader mode QMK Toolbox will display this message:
  STM32 DFU device connected (WinUSB): STMicroelectronics STM32 BOOTLOADER (0483:DF11:2200)

Revision 2: "single pcb"

• STM32F402RCT6 MCU with IS31FL3733 LED driver, using stm32-dfu bootloader. Integrated USB connection.

• Upon entering bootloader mode QMK Toolbox will display this message:
  STM32 DFU device connected (WinUSB): STMicroelectronics STM32 BOOTLOADER (0483:DF11:2200)

Revision 3: "FXTwink single pcb"

• STM32F402RCT6 MCU without separate LED driver, using tinyuf2 bootloader. Integrated USB connection.

• Upon entering bootloader mode the board will appear in your computer's file system as a new USB mass storage device.