void setup() {
  Serial.begin(115200);
  pinMode(6, OUTPUT);
  digitalWrite(6, HIGH);
}

void loop() {
  float sensorValue = analogRead(A0);
  float gpiVoltage = sensorValue * (5.0 / 1023.0);
  Serial.println("A0 = " + String(gpiVoltage) + "V");
  delay(500);
}