qmk_firmware/keyboards/handwired/meck_tkl/blackpill_f401/info.json

{
    "matrix_pins": {
        "cols": ["B4", "B5", "B6", "B7", "B8", "B9", "A1", "A2", "A3", "A4", "A5", "A6", "A7", "B0", "B1", "A0", "B10"],
        "rows": ["B15", "A8", "A9", "B14", "A15", "B3"]
    },
    "diode_direction": "COL2ROW",
    "indicators": {
        "caps_lock": "C13",
        "on_state": 0
    },
    "processor": "STM32F401",
    "bootloader": "stm32-dfu",
    "board": "BLACKPILL_STM32_F401"
}