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Topic: Make my ATmega 328 a stand-alone micro controller? (Read 1 time) previous topic - next topic

fungus

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

InduinoX

Then what's the use of an external 16mhz if an internal 8mhz would do by itself?

tack


Then what's the use of an external 16mhz if an internal 8mhz would do by itself?

A microprocessor that runs at up to 16MIPS, instead of 8MIPS.

If your sketch is light load then maybe 8Mhz is fine for you. Maybe even lower, in which case there are power savings that can be made, since requirements are lower at lower speeds. You could go as far down as 1Mhz.

strykeroz

There's quite a few pages in the datasheet dedicated to this.  One of the notes also states that the internal clock isn't as accurate as an external crystal, so the timer functions on your Arduino will drift away more from the real world time.
"There is no problem so bad you can't make it worse"
- retired astronaut Chris Hadfield

fungus


Then what's the use of an external 16mhz if an internal 8mhz would do by itself?


The internal 8MHz isn't very accurate. It might be 7.9 or 8.1 depending on temperature and voltage.

It's good enough to run programs but if you need accurate timing or high speed serial communications (for example) then it isn't enough.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

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