#define LED_PIN 6 // must support PWM
#define STEADY_WHITE 2
#define STEADY_GREEN 0
#define FADE_SPEED 2 // lower is faster

const uint8_t PROGMEM gamma8[] = {
  7,8,9,10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16,
  17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 25,
  25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 35, 36,
  37, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50,
  51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68,
  69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
  90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 11, 112,
  113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,128,
  129, 130, 131, 132, 133, 134, 135,136, 137, 138,139, 140,141, 142,143,
  144,145, 146,147, 148,149, 150,151, 152, 153, 154, 155, 156, 157, 158, 159, 160,
  161,162,163, 164,165,166, 167, 168,169,170, 171,172, 173,174, 175,176,
  177,178,179, 180,181, 182,183, 184,185, 186,187,188, 189,190, 191,192, 193,194,195,
  196, 197, 198, 199, 200, 201,202, 203,204, 205,206,207, 208,209, 210,211, 212,213,
  214,215,216,217, 218,219, 220,221,222, 223,224, 225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
  240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255
};

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(STEADY_WHITE, OUTPUT);
  pinMode(STEADY_GREEN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
{
  }
  {digitalWrite(STEADY_WHITE,HIGH);
  digitalWrite(STEADY_GREEN,HIGH);
  }
  
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(20);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(400);                       // wait for a second
 for (int i = 0; i < 255; i++) {
    analogWrite(LED_PIN, pgm_read_byte(&gamma8[i]));
    delay(FADE_SPEED);
  }
  for (int i = 255; i > 0; i--) {
    analogWrite(LED_PIN, pgm_read_byte(&gamma8[i]));
    delay(FADE_SPEED);
  }
}