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Topic: code size (Read 2 times) previous topic - next topic

AWOL

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So why does the atmel spec sheet say 35 to 250 us, are you saying they are incorrect?

No, not at all - the speed of the ADC depends on its clock rate, and the Arduino sets it at 125kHz.
A conversion takes 13 cycles of this clock.
104 is between 35 and 250, so everyone is happy.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

ardnut

Are you being serious??

ADC on these chips is succ. approx, the time to convert depends upon the data. That is why is can be anywhere within the stated range. Where do you get your stated 13 cycles from?

I presume when showing the spec for conversion timing they are showing its best value , not an artificialy slow one calculated by underclocking the chip.

Since the ADC cct has its own clock this conversion time probably does not even depend on what the main clock rate is set to.

AWOL

#22
Jul 11, 2012, 09:36 am Last Edit: Jul 11, 2012, 09:38 am by AWOL Reason: 1
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Are you being serious??


Are you being a troll?

RTFM.

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So why does the atmel spec sheet say 35 to 250 us

It doesn't; it says 13 to 260us
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

dxw00d

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Where do you get your stated 13 cycles from?


Datasheet - 21.4:
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A normal conversion takes 13 ADC clock cycles. The first conversion after the ADC is switched
on (ADEN in ADCSRA is set) takes 25 ADC clock cycles in order to initialize the analog circuitry.

Nick Gammon



ADC on these chips is succ. approx, the time to convert depends upon the data.


That's complete nonsense. Read the datasheet:

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A normal conversion takes 13 ADC clock cycles.

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