(1)    A director may waive any notice required by this chapter, the articles of incorporation or bylaws before or after the date and time stated in the notice. Except as provided by sub. (2), the waiver shall be in writing, signed by the director entitled to the notice and retained by the corporation.

   (2)   A director’s attendance at or participation in a meeting waives any required notice to him or her of the meeting unless the director at the beginning of the meeting or promptly upon his or her arrival objects to holding the meeting or transacting business at the meeting and does not thereafter vote for or assent to action taken at the meeting.