The nano will be in the standalone controller, it will have inputs from 2 encoder breakout boards with 4 encoders each on. And it will be controlling a 20x4 lcd screen. All of this will be done over I2c.
The controller will be linked to the uno via 8bit serial over usb if possible.
The uno is used as i believe it has a faster communication signal with the motor, therefore i can get the speeds and changes i want.
I am open to recommendations on hardware though!