Thanks Grant. You suggested hooking the 32U4 5 volt output to the Pi. I see a couple people who suggest that I can do this by connecting to the GPIO pins. Is that what you were suggesting? If so is the 5v output from the 32U4 regulated and safe to hook up like that or would I need a diode or something?
Also with an Arduino Uno I can connect pi GPIO pins to pin 0 and 1 to program and to send and receive serial data. Is that true for the 32U4? I see I’d lose the ability to use the LCD, but the pi is going to cover it anyway so no big loss.