elobau can bus joystick

# https://www.amazon.de/gp/product/B07Q812QK8
# https://www.fischl.de/usbtin/
# https://python-can.readthedocs.io/en/master/


from subprocess import run
from can.interfaces.socketcan import SocketcanBus


def set_baudrate(interface, bitrate):
    run(["sudo", "ip", "link", "set", interface, "type", "can", "bitrate", str(bitrate)])


def _set(interface, up_down):
    run(["sudo", "ip", "link", "set", up_down, "dev", "can0"])


def set_up(interface):
    _set(interface, "up")


def set_down(interface):
    _set(interface, "down")


def can_joystick(data):
    D1, D2, D3 = data
    if 0 < D1 <= 0x64:
        direction_x = "right"
        x = D1
    elif 0x9c <= D1 <= 0xFF:
        direction_x = "left"
        x = 0x100 - D1
    elif D1 == 0:
        direction_x = "middle"
        x = 0

    if D2 == 0:
        y = 0
        direction_y = "middle"
    else:
        y = 0x100 - D2
        direction_y = "down"

    return f"{x:03d}: {direction_x} | {y:03d}: {direction_y} | Button: {bool(D3 & 0x01)}"



if __name__ == "__main__":
    interface = "can0"
    bitrate = 125_000
    node_id = 0x1a4
    set_down(interface)
    set_baudrate(interface, bitrate)
    set_up(interface)
    bus = SocketcanBus(interface)
    while True:
        if (msg := bus.recv()).arbitration_id == node_id:
            print(" "*80, end="")
            print("\r", end="")
            print(can_joystick(msg.data), end="", flush=True)