Suggestion to solve system clock issue #2
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I just realized my attached patch is somewhat wrong. Since you are using the double speed operation in asynchronous mode (by setting the U2X0 bit UCSR0A). Setting that bit will reduce the divisor of the baud rate divider from 16 to 8, so the formula should multiply by 8 instead. |
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Since the serial.h code is only working with a 16MHz clock I've been using this hack since I run my clock system clock at different speeds. The following suggestion uses a small macro which takes the F_CPU value defined in Hz and calculates the baud rate based on that. It's not very nice, but it works as far as I know.
The formula is:
see http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=45341 for more info regarding this, but you probably know it already.
The "bad" with this commit is that you end up being dependent on having the F_CPU value set(either in Makefile or before importing the serial.h code).