ftd2xx.py 文件源码

def listDevices(flags=0):
    """Return a list of serial numbers(default), descriptions or
    locations (Windows only) of the connected FTDI devices depending on value
    of flags"""
    n = _ft.DWORD()
    call_ft(_ft.FT_ListDevices, c.byref(n), None, _ft.DWORD(LIST_NUMBER_ONLY))
    devcount = n.value
    if devcount:
        # since ctypes has no pointer arithmetic.
        bd = [c.c_buffer(MAX_DESCRIPTION_SIZE) for i in range(devcount)] +\
            [None]
        # array of pointers to those strings, initially all NULL
        ba = (c.c_char_p *(devcount + 1))()
        for i in range(devcount):
            ba[i] = c.cast(bd[i], c.c_char_p)
        call_ft(_ft.FT_ListDevices, ba, c.byref(n), _ft.DWORD(LIST_ALL|flags))
        return [res for res in ba[:devcount]]
    else:
        return None