Battery_info:model_name

skyyuzhang · December 12, 2018, 9:05am

why my model is numbers? can I mae text? or make stuff like the end picture? thank you!!!

pavel.kirienko · December 12, 2018, 9:57am

ASCII text and integer arrays are represented by the protocol identically (this could be improved; however, this is a minor issue of a very low priority; after all, the protocol is designed for control tasks in the first order, where text is rarely useful). When you see text in the message view widget, that text is rendered by the GUI tool itself when it believes that the array of integers might actually be a sensible string of text. The heuristics for that decision are implemented here:

github.com

UAVCAN/pyuavcan/blob/1d799f4efbaa29128140ffeed9b4c388aaaba3c4/uavcan/introspect.py#L70


if t.value_type.category == t.value_type.CATEGORY_PRIMITIVE:
    def is_nice_character(ch):
        if 32 <= ch <= 126:
            return True
        if ch in b'\n\r\t':
            return True
        return False


    as_bytes = '[%s]' % ', '.join([_to_yaml_impl(x, indent_level=indent_level + 1, uavcan_type=t.value_type)
                                  for x in obj])
    if t.is_string_like and all(map(is_nice_character, obj)):
        write('%r # ', obj.decode())
    write(as_bytes)
else:
    if len(obj) == 0:
        write('[]')
    else:
        for x in obj:
            indent_newline()
            write('- %s', _to_yaml_impl(x, indent_level=indent_level + 1, uavcan_type=t.value_type))

The text in your example is not a valid ASCII string because it contains ordinals outside of the printable ASCII range (zeros and 128).