int adcValue; // our adc value
float voltage; // calculated voltage level

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600); // serial port with baud rate (speed) of 9600
}

void loop() {
  // put your main code here, to run repeatedly:
  adcValue = analogRead(A0); // read and convert analog signal of A0 to digital
  voltage = adcValue * (5.0 / 1023.0); // calculate voltage according to adc
  
  // send results to computer
  Serial.print("convertValue:");
  Serial.println(adcValue);
  Serial.print("Voltage:");
  Serial.println(voltage);
  delay(500); // delay 500 ms
}