qmk_firmware/keyboards/handwired/splittest/teensy_2/keyboard.json

{
    "matrix_pins": {
        "cols": ["F7"],
        "rows": ["F5"]
    },
    "diode_direction": "COL2ROW",
    "split": {
        "soft_serial_pin": "D1"
    },
    "ws2812": {
        "pin": "D3"
    },
    "processor": "atmega32u4",
    "bootloader": "halfkay",
    "features": {
        "bootmagic": false,
        "mousekey": false,
        "extrakey": false,
        "console": true
    }
}