Command to read in analog signal from a connected Arduino board
Board pointer, to indicate which board to use to differentiate one board from another
Analog pin to measure the signal
Reading in the range of 0-1023 to to indicate the input voltage from 0-5V
Arduino UNO board has 6 analog input ports (A0 to A5), the Arduino Mega board has 16 analog input ports (A0 to A15). The 10 bits channels convert the analog input from 0 to 5 volts, to a digital value between 0 and 1023.