// Define GPIO pins for the Pico
const int redPin = 14;   
const int greenPin = 15; 
const int bluePin = 16;  

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  // We have 3 transitions (R->G, G->B, B->R).
  // 10,000ms total / 3 transitions = 3,333ms per transition.
  // 3,333ms / 255 steps = ~13ms delay.
  
  int fadeDelay = 13; 

  // 1. Red to Green
  for (int i = 0; i <= 255; i++) {
    analogWrite(redPin, 255 - i);
    analogWrite(greenPin, i);
    analogWrite(bluePin, 0);
    delay(fadeDelay);
  }

  // 2. Green to Blue
  for (int i = 0; i <= 255; i++) {
    analogWrite(redPin, 0);
    analogWrite(greenPin, 255 - i);
    analogWrite(bluePin, i);
    delay(fadeDelay);
  }

  // 3. Blue to Red
  for (int i = 0; i <= 255; i++) {
    analogWrite(redPin, i);
    analogWrite(greenPin, 0);
    analogWrite(bluePin, 255 - i);
    delay(fadeDelay);
  }
}