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Topic: Two Arduino's One Board? (Read 870 times) previous topic - next topic

Nick Gammon

Oct 16, 2012, 06:35 am Last Edit: Oct 16, 2012, 06:37 am by Nick Gammon Reason: 1

Also, if you want to use the clock source (system clock - which I believe is any of the clock sources, based on my reading of the datasheet) to drive another device, you get that from the CLKO pin (PB0, pin 14 on the 28 pin PDIP).

I just tried that, and with a 16 MHz Uno I got a 16 MHz output on PB0.  So you could have a single crystal (or resonator to save the capacitors) on processor A, configure it to output its clock, and take the external clock on processor B. That would also keep them exactly in step.

Nick Gammon

They can still have the standard bootloader. Uploading the bootloader changes the fuses (at least doing it in the IDE does) but you only ever need to upload the bootloader once.


Yea so specifically what parts would they be able to share? I know for sure they cannot share the 16MHz Crystal.

Yes they can. Sort of...you can tell one of them to output the clock on a pin and the other one can use that for clock input.

Why do i not need to use the clock Crystal? I thought the ATmega chip needed that. Can you please Elaborate?

They have internal 8mHz clocks which you can use.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

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