In firmware/bootloaderconfig.h, it says D+ must also be connected to interrupt pin INT0. For ATmega328P, INT0 is on PD2, so USB D+ connects to PD2. However, 328P has a second INT1 on PD3. From the official datasheet, it looks like no difference when they serve as external interrupt sources.
I haven't tested it, but in theory does D+ also work on INT1 (PD3)? And more specifically, is it possibly reliable to set INT1 as D+ and INT0 as D-?
In firmware/bootloaderconfig.h, it says
D+ must also be connected to interrupt pin INT0. For ATmega328P, INT0 is on PD2, so USB D+ connects to PD2. However, 328P has a second INT1 on PD3. From the official datasheet, it looks like no difference when they serve as external interrupt sources.I haven't tested it, but in theory does D+ also work on INT1 (PD3)? And more specifically, is it possibly reliable to set INT1 as D+ and INT0 as D-?