How can i make ammeter using atmega16 adc?

Question

How can i make ammeter using atmega16 adc?

Answer 1

The part has an 8 channel 10 bit ADC on it. The data sheet I found has no details about the inputs. Possibly there is a better data sheet out there.

If your only purpose with this chip is to use it as an ammeter, I'd find a simpler chip, This is a special processor with it's own programming language, lots of registers, lots of pins.

You would probably have to buffer the ADC input with an opamp.

good luck

.

Answer 2

ADC's measure voltage.   (you can measure current using Ohms law)

An ADC takes a voltage input and compares it to a reference voltage.   A 10 bit ADC will return a value from zero to a max of 1024. THe max count of 1024 represents an input voltage that is equal to or greater than the reference. A zero count meant that a 0V input.  Count values between 0 and 1024 are the proportion to which the input voltage compares to the reference voltage. So a count of 512 (half of 1024) would mean that the input is 1/2 of the reference vlotage

Reference voltages can be no higher than Vcc and may be referenced to a voltage standard that is internal or external to the uC.

To measure current you need to use Ohms law and measure voltage across a resistor.   E = I * R

Using a small value resistor of known value you determine the ADC count voltage across that resistor convert the count to a voltage and divide by the resistance.