Here i m going to explain how to read analog data from arduino and
i m supposed to u have basic knowledge of arduino uno shield. In arduino analog read perform analog to digital converter with 2^10 resolution.That mean if you are using 5V then it will divided by 2^10 which is 4.26mV change.Means for every change in 4.26mV there is change of bit value.Its bit value lies between 0-1023.
This is a simple example read analog reading.
1st step to make voltage divider circuit.Take input from arduino 5v source and ground pin.Connect it to both side of potentiometer and middle pin of potentiometer goes to analog read input A0 pin of arduino.It will shown in figure below