// Project 2: ESP32 Analog Inputs (ADC)
// Read a potentiometer on GPIO 4 and print the value (0-4095) plus the
// approximate voltage it represents.

const int potPin = 4;   // potentiometer wiper -> GPIO 4 (ADC2_CH0)

int potValue = 0;       // stores the raw ADC reading (0..4095)

void setup() {
  Serial.begin(115200);
  delay(500);           // give the Serial Monitor a moment to connect

  Serial.println();
  Serial.println("==============================================");
  Serial.println(" Project 2: ESP32 Analog Inputs (ADC)");
  Serial.println("==============================================");
  Serial.print  ("Potentiometer -> GPIO ");
  Serial.println(potPin);
  Serial.println("12-bit ADC: 0 = 0 V ... 4095 = 3.3 V");
  Serial.println("Turn the knob and watch the value change.");
  Serial.println("----------------------------------------------");
}

void loop() {
  // Read the analog value: 0 (0 V) .. 4095 (3.3 V)
  potValue = analogRead(potPin);

  // Convert the raw reading to an approximate voltage for readability
  float voltage = potValue * 3.3 / 4095.0;

  Serial.printf("Pot: %4d / 4095   (~%.2f V)\n", potValue, voltage);

  delay(500);
}