Atmega328pb bootloader not working about minicore

[MCUdude]

Sorry, I'm not able to look into this at the moment. It may be because the 328PB isn't able to drive the external oscillator as "hard" as the 328P can (lack of full swing oscillator option in the fuse settings).

You may also try Watterott's repo.
Also, you should also check if the 1MHz or 8 MHz internal oscillator option work. Note that the USBasp is usually too fast for a 1 MHz clock, so you should probably use 8 MHz internal instead.

[MCUdude]

You haven't replied to your issue here and over at the Pololu repo. Did you solve the issue or did you just give up?

[Georgesorin]

Sorry for late response.

No, i will never give up on anything (about electronics, always there is a way to make it work)

So i removed the 16mhz crystal from my custom board and i have burn the 8mhz bootloader.

And now is working like a charm.
The only thing that scares me right now is that i pass 23kb of the flash memory with my code, and the Arduino IDE is warning me that is possible to have instability. if i will have any problem with that i will come here again, with a new topic.

Thank you so much for your help!

[MCUdude]

Great to hear you got it working! I'm pretty sure your issue is caused by the lacking full swing oscillator option on the 328pb. IMO it was a stupid move by Atmel to remove this feature.