qmk_firmware/keyboards/bastardkb/tbkmini/v2/stemcell/info.json

{
    "keyboard_name": "TBK Mini STeMCell",
    "usb": {
        "device_version": "2.0.0"
    },
    "split": {
        "soft_serial_pin": "D2"
    },
    "processor": "STM32F411",
    "bootloader": "stm32-dfu"
}