Please make me understand analog read bit calculation

I am writing here as i am unable to find any article on this

I am unable to understand the ADC bit calculation.. I need some help in understanding..

I came across the page here http://arduino.cc/en/Reference/AnalogReadResolution

Where it is written the default is 10 bit resolution which is (0 - 1023)
I know that the ADC scale is 1024 divisions in default.. But I do not understand how does 10 bit = 1024 and 12 = 4096 divisions..

210=1024
212=4096

1 BIT of data can only hold 0 or 1 (two possible values)

2 bits can hold 00, 01, 10, or 11 (that's 4 possible values)

3 bits can hold 000, 001, 010, 011, 100, 101, 110, 111 (that's 8 possible values)

etc..

A byte of data has 8 bits, it can hold any one of 256 values

a 10 bit value is a binary value that has 10 binary bits. it can hold any one of 1024 different values. from 0 to binary 1111111111 (ie 0 to 1023 inclusive)

Thank a lot..:slight_smile:

I need to scale a 4 - 20mA signal to a 0000 to 9999 display..

The reading should be very precise, as this will be the measurement of thickness in micron.
What will be the best analog bit resolution, and what AVR can I use ..??

You're looking at 14 bits of precision which is beyond the normal scope of the onboard ADC The simplest solution would be to use an external ADC chip.

If you're wondering about why it's 14 bits, log210000 = 13.28.

That's not an easy thing to do and you'll need to control noise very, very carefully.

AWOL:
If you're wondering about why it's 14 bits, log210000 = 13.28.

That's not an easy thing to do and you'll need to control noise very, very carefully.

And if the full scale represents 20ma, even his breathing :slight_smile:

Other anomalous results may be incurred from the tidal influences on the bedrock. Try to avoid taking readings around the full moon. :slight_smile:

Hi, what is your measuring device that is micron resolution with 4 to 20mA output.

16mA is going to represent 10,000 levels.

0.016/10,000=0.0000016 A or 1.6uA per micron.

Noise is going to be a big problem as AWOL and KenTF hve said.

A device with that resolution must have another type of output.

Tom....... :slight_smile: