Crystal vs Clock Oscilator

Hello everyone,

I have some experience with microcontrolers but much less experience with Arduino specifics.

My problem is this:

I want to connect an ATMEGA328 directly to a clock line (no crystal or ressonator).

Does the Arduino Bootloader configure the chip to accept clock inputs just on OSC1 pin?

Base Arduino board is Arduino Pro Mini @ 3.3V

Thanks in advance,


It seems to be a fuse setting. The bootloader has nothing to do with clock source. Read 328 data sheet chapter 9 system clock and clock options, sections 2 and 8 about clock sources and external clock. There are 3 options for accepting external clock signals, each with more startup time than the last.

Thank you liudr for your help. It helped me imensely.

You are welcome. I had a hunch so I did some reading myself. I might just try that in a breadboard setup myself with 2 mcus.