Hi Pete,
Thanks a lot for your reply. I definitely will go the same way with the description you gave me. I suppose you never had problems with the ATTiny85 board from stopping to work ?
As for the router, I had a similar problem of the router blocking at a certain point so now I do it the hard way. I cut the power to it with a oldfashioned clock driven socket for a quarter of an hour during night time. So far so good !
Robert