byte redPin = 11; 
byte greenPin = 10; 
byte bluePin = 9; 

int steps = 40;
int stepCount = 0 ; 

int currentRed = 255, currentGreen = 0, currentBlue = 0;
int targetRed = 255, targetGreen = 255, targetBlue = 0;
unsigned long lastFadeTime = 0;
unsigned long fadeInterval = 1000; // ms

void setup() {
 pinMode(redPin, OUTPUT); 
 pinMode(greenPin, OUTPUT); 
 pinMode(bluePin, OUTPUT); 
 Serial.begin(115200);
   
}

void loop() {

  if (stepCount >= steps) return;

  unsigned long now = millis();
  if (now - lastFadeTime >= fadeInterval) {
    lastFadeTime = now;
    stepCount++;
    Serial.print(stepCount, DEC);

    int r = map(stepCount, 0, steps, currentRed, targetRed);
    int g = map(stepCount, 0, steps, currentGreen, targetGreen);
    int b = map(stepCount, 0, steps, currentBlue, targetBlue);
    
    analogWrite(redPin, r);
    analogWrite(greenPin, g);
    analogWrite(bluePin, b);

    if (stepCount == steps) {
      currentRed = targetRed;
      currentGreen = targetGreen;
      currentBlue = targetBlue;
    }
  }
}