Starting to move test object code into hub sketch.
Improved the code, I think, by simplifying renderNextFrame().  Compiles
OK but not tested.
More changes. Not tested.
Animation side works ok.  But realised that SoftwareSerial can't listen
to two ports at once, so sensor polling is broken.  Will need to migrate
to Mega.
Converted to hardware serial.  Tested OK on Serial1 and Serial 2.