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Topic: CKSEL[3:1] 110 OR 111 for (external) 8MHz crystal on TINY45? (Read 119 times) previous topic - next topic

leafybye

Is one better than the other using 8Mhz crystal for clock on an ATtiny45?

Why? I used a sketch that output 10kHz to test the relative accuracy of the frequency meter on my DMM by using an 8MHz crystal. Fortunately my meter is accurate, and measured the square wave to be 9.999 kHz.

In other words, is there any particular advantage when using a 8MHz crystal to selecting the frequency range;
3. 0 - 8.0 MHz or the frequency range 8.0 - MHz when setting the low fuse?

I used this setting with avrdude, and used an 8Mhz external crystal :

avrdude -p t45 -c usbtiny -U lfuse:w:0xFD:m



gilshultz

This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

leafybye

Not really, just a bit more resolution.
Resolution of what? Please elucidate.
8 is within 3-8, and also within 8- , is there an advantage to one over the other using an external 8MHz crystal?

jremington

Try both options and let us know which is better.

DrAzzy

I suspect the difference will come down to power consumption and/or resilience to poor layout  of crystal traces, and that both will workwork with comparable frequency accuracy. 
ATTinyCore for x4/x5/x61/x7/x8/x41/1634/828/x313 megaTinyCore for the megaavr ATtinies - Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts, mosfets, awesome prototyping board in my store http://tindie.com/stores/DrAzzy

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