how good is a 10bit ADC in a 8bit AVR

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#1
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So recently I am experimenting with AVR's ADC, I found that I am not happy with the ADC reading, I mean the ADC reading is not bad, but I just want it better.

it makes me thinking: how good is a 10bit ADC in 8bit AVR compares to other general stand alone ADC?

is it about the same? better? worse?

I know it's hard to compare without given a specific chip. but I have no experience with other ADC chip either.

Hope I am not asking too much.

Zhuhua Wu - Electronic Engineering Student

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Quote:
how good is a 10bit ADC in 8bit AVR compares to other general stand alone ADC?

As good as the specification quoted in the data sheet!

Quote:
I am not happy with the ADC reading, I mean the ADC reading is not bad, but I just want it better.

What is that you are not happy with? What do you want to be better? Linearity, conversion time, monoticity ?????

Quote:
Hope I am not asking too much.

Not at all. I hope that I am not asking you too many questions! :)

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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The main thing I am looking for is accurately :)

Zhuhua Wu - Electronic Engineering Student

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Quote:

The main thing I am looking for is accurately

But you have to tell us much more. What accuracy do you desire? what values are you getting?

And then, it is not going to be the fault of the AVR's ADC. You can achieve near-10-bit results if:

-- The analog subsystem is squeaky-clean. No ripple or drift anywhere.
-- That is difficult in the real world, so oversampling and averaging will help.
-- Conversions must be made within specs. In particular, the signal must have enough drive, and the ADC clock must be slow enough.

So, answer the questions first, tell your setup, show some code, and the results.

A very similar discussion here:
https://www.avrfreaks.net/index.p...

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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If 10 bits isnt good enough, get a 12 or 14 or 16 bit a/d converter and read it from the spi.

Imagecraft compiler user

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More information is needed, for sure. In addition to what has already been said,
What does he mean when he says "accuracy" ?
How did he determine that the AVR ADC is not "accurate" ?
Does he have proper decoupling caps ?
What voltage reference does he use ?
What does his code look like ?

Sid

Life... is a state of mind