const int rpin = 11;
const int bpin = 10;
const int gpin = 9;
int i;

void setup() {
  pinMode(rpin, OUTPUT);
  pinMode(bpin, OUTPUT);
  pinMode(gpin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  for (i = 255; i > 0; i--)
  {
    analogWrite(rpin, i);
    analogWrite(bpin, 255 - i);
    analogWrite(gpin, 128 - i);
    delay(1);
  }

  for (i = 0; i < 255; i++)
  {
    analogWrite(rpin, i);
    analogWrite(bpin, 255 - i);
    analogWrite(gpin, 128 - i);
    delay(1);
  }
  Serial.println(i, DEC);
}