Can't program 328PB using USB AVR programmer V2 when no external crystal

Target: Pololu A-star 3.3v/8Mhz with 328PB part.
I’m using AVR USB programmer V2 as ISP programmer.
I’m using Arduino IDE / avrdude with MINCORE board def.
I can program parts and have no problem selecting internal or external oscillator.
In this case, I program it to run BLINK using internal oscillator. I desolder the resonator, it comes up running. Now, I can no longer program the part. avrdude throws a “initialization failed, rc=-1” error.
Using ISP programmer, I should not need a resonator/crystal on the micro, no?


To use or program an AVR, its clock circuit needs to be functioning, so if the fuses of the AVR are programmed to use an external oscillator, then you would need an external oscillator.

You mentioned programming the A-Star 328PB Micro - 3.3V, 8MHz successfully using the MiniCore package. You should check the CKSEL fuse bits in the MiniCore’s board definition you used to see which clock source option was selected.

- Amanda