#define LIGHT_SENSOR_PIN 3 // GLYPH-C6 pin GPIO 3 (ADC channel)

void setup() 
{
  // initialize serial communication at 115200 bits per second:
  Serial.begin(115200);

  // set the ADC attenuation to 11 dB (up to ~3.3V input)
  analogSetAttenuation(ADC_11db);
}

void loop() 
{
  // reads the input on analog pin (value between 0 and 4095)
  int analogValue = analogRead(LIGHT_SENSOR_PIN);

  Serial.print("Analog Value = ");
  Serial.print(analogValue);   // the raw analog reading

  // We'll have a few thresholds, qualitatively determined
  if (analogValue < 40) 
  {
    Serial.println(" => Dark");
  } 
  else if (analogValue < 800) 
  {
    Serial.println(" => Dim");
  } 
  else if (analogValue < 2000) 
  {
    Serial.println(" => Light");
  } 
  else if (analogValue < 3200) 
  {
    Serial.println(" => Bright");
  } 
  else 
  {
    Serial.println(" => Very bright");
  }

  delay(100);
}