Intresting thing happened this weekend. The nodes all appeared 'down' again and yet in all screens (resources and topology) the GW was showing as up. It was a mystery. Then, I tried to turn on some lights, it worked.
So this time MyController is not getting data from the nodes, but is able to send commands to the nodes correctly. I am beyond puzzled by this as it is no longer a GW faliure nor is it a NRF24l01 lock up.
@jkandasa No problem..... Mysteriously it seems to have resolved itself. Today is 'update' day for the pi and I thought I'd wake to a dead http connection. But no! - there was mycontroller running as normal. Maybe I just didn't give it enough time to settle down in previous tests......Ah well, it's alright at the moment so this is solved now!