#include <Adafruit_NeoPixel.h>

#define LED_PIN    2     // GPIO2 on Raspberry Pi Pico
#define NUM_LEDS   16    // Change to your ring’s LED count

Adafruit_NeoPixel ring(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  Serial1.begin(115200);
  Serial1.println("Hello, Raspberry Pi Pico!");

  ring.begin();          // Initialize NeoPixel ring
  ring.show();           // Turn off all pixels
}

void loop() {
  // Turn ON all LEDs (red in this case)
  for (int i = 0; i < NUM_LEDS; i++) {
    ring.setPixelColor(i, ring.Color(255, 0, 0));  // Red color
  }
  ring.show();
  delay(2000);  // Wait 2 seconds

  // Turn OFF all LEDs
  for (int i = 0; i < NUM_LEDS; i++) {
    ring.setPixelColor(i, 0);  // Off
  }
  ring.show();
  delay(2000);  // Wait 2 seconds
}