Question

Why for the 8 bit analog input we select Vref as the 2.56V?

(a) to obtain each degree count as the 2.56V

(b) to get 2.56V at the output

(c) to obtain each degree count as the 10mV

(d) to get 10mV as the output

This question was addressed to me in semester exam.

This question is from Sensor Interfacing topic in portion AVR Microcontroller of Microcontroller

Answer 1

Right choice is (c) to obtain each degree count as the 10mV

For explanation: For an 8 bit analog input, each degree count is calculated as the Vref/256, so if Vref is selected as 2.56V then we can obtain 10mV for each degree count of the scale.