How to wire ATMega32U4 Hardware Serial to Arduino Mega2560?
After looking more into pin 0 &amp; 1 and having helpful comments, it turns out they are a separate hardware serial pin from the USB serial. They are &quot;Serial1&quot; which is different than &quot;Serial&quot; found from the USB.
I've tested this with a basic setup and the micro was able to communicate with both my computer via USB and the Mega board at the same time.