Comment out some of the main programs debug print statements plus add yield call to main loop.

yield can now call SerialEvent.

Put hack in that if the user has not overwritten the SerialEvent function, the weak linked one will turn off calling itself...

The B2 board has different IO pins here for these two pins

Saves power and prevents heating

todo:
analogInputToDigitalPin(p)
digitalPinHasPWM(p)

Fixed the Serial2 object to use the new correct pins, plus made Serial8 only valid for T4 B1 (not B2).

Also I defined IO pins for the six signals associated with the SD Card slot.

I have tested these both as IO pins and now as SPI2

Moved from my flexio_t4 library.
Libary was updated to see if already defined before it now defines it.

Code from :: https://community.nxp.com/thread/389002
Name the fault dump info
New weak to override :: HardFault_HandlerC()

Allow the user to call setTX with the one hardware pin, and hopefully allow them to turn on Open Drain mode or turn it back off.  I don't currently have any test cases that use this, so not sure how well it works.