#include <Adafruit_NeoPixel.h>
#define left_ring        13
#define right_ring       3
#define NUMPIXELS 16 
Adafruit_NeoPixel left_pixels(NUMPIXELS, left_ring, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel right_pixels(NUMPIXELS, right_ring, NEO_GRB + NEO_KHZ800);

void setup() {
  left_pixels.begin(); 
  right_pixels.begin(); 
}

void loop() {
  for (int k = 0 ; k < 16 ; k++)
  {
    left_pixels.clear(); // Set all pixel colors to 'off'
    left_pixels.setPixelColor(k, left_pixels.Color(250, 150, 0));
    left_pixels.show();   // Send the updated pixel colors to the hardware.
    right_pixels.clear(); // Set all pixel colors to 'off'
    right_pixels.setPixelColor(k, right_pixels.Color(250, 150, 0));
    right_pixels.show();   // Send the updated pixel colors to the hardware.    
    delay(250); // Pause before next pass through loop
  }
}