[wlug] On a similar DYI theme

28 x wireless keyboards and mice

For each row have a wireless ethernet router

You definitely should not use so many wireless mice in the same room. keyboards are ok but the interference and drops on the mice are frustrating. We used them in a room of about 16 poeple and we had to convert to wired. Also you might want to check if r pis bluetooth has drivers yet. pretty sure a hub/switch is cheaper, you can get 10/100 for under $20 -- Kind Regards Rowan Schischka