qmk_firmware/keyboards/tronguylabs/m122_3270/bluepill/info.json

{
    "usb": {
        "device_version": "0.0.3"
    },
    "matrix_pins": {
        "cols": ["B1", "B10", "B11", "B12", "B13", "B14", "B15", "A8", "B0", "A10", "A7", "A6", "A15", "B3", "B4", "B5", "B6", "B7", "B8", "B9"],
        "rows": ["C13", "C14", "C15", "A1", "A2", "A3", "A4", "A5"]
    },
    "diode_direction": "ROW2COL",
    "processor": "STM32F103",
    "bootloader": "stm32duino"
}