qmk_firmware/keyboards/handwired/macroboard/f401/keyboard.json

{
    "usb": {
        "shared_endpoint": {
            "keyboard": true
        }
    },
    "matrix_pins": {
        "cols": ["A5", "A6", "A7", "B0", "B1", "B10"],
        "rows": ["A4", "A3", "A2", "A1", "A0"]
    },
    "diode_direction": "COL2ROW",
    "ws2812": {
        "driver": "pwm"
    },
    "development_board": "blackpill_f401",
    "features": {
        "bootmagic": true,
        "mousekey": true,
        "extrakey": true,
        "nkro": true,
        "rgblight": true
    }
}