I managed to flip the rx/tx lines on a project I'm working on. My GPS RX is going to my ATMega's RX, which is clearly wrong. Since the pin map lists the rx2 and tx2 lines as pins D16 and D17, I'm hoping I can work around this for the time being by using SoftwareSerial over those pins and flipping them virtually. This doesn't seem to be working. Is there something I need to do to disable the native UART? Can this work in principle?
There is no pin change interrupt available on PH1, hence you cannot use SoftwareSerial. You will need to resort to a polled software UART instead.
Cut the traces with a razor knife and use a wiring pencil to solder in a crossed connection to fix the wiring problem.