Debug

Microchip not have implementation for OpenOCD via ICSP, otherwise I will integrate it
Actually, the ICSP is like SWD interface
( MIPS JTAG requires a lot of wiring )

If anyone cares, here is an implementation of the PicKit4 protocol

So, use printf()

for Arduino:

• -DDBG enable printf() for UART1 ( without Serial )
• or Serial.debug( true ) redirect printf for this Serial
• or Serial.print()