초음파센서와 네오픽셀을 연동하려 하는데요

초음파센서가 처음에값만 읽고 그 후에는 0cm로 읽히더라구요...

코드 어느 부분이 잘못된걸까요?ㅠㅠ

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

const int trigPin = 8;
const int echoPin = 7;

#define PIN 5

//CRGB leds[NUM_LEDS];

Adafruit_NeoPixel strip = Adafruit_NeoPixel(30, PIN, NEO_GRB + NEO_KHZ800);

void setup()
{
  Serial.begin(9600);
  //FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
  // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
  #if defined (__AVR_ATtiny85__)
    if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
  #endif
  // End of trinket special code
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
}

void loop()
{
  long microsecondsToInches(long microseconds);
  long microsecondsToCentimeters(long microseconds);
  long duration, inches, cm;
  digitalWrite(trigPin, HIGH);
  delay(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);
   
  Serial.print(inches);
  Serial.print("in");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();

  void colorWipe(uint32_t c, uint8_t wait);

  if(cm>10)
  {
    colorWipe(strip.Color(0, 0, 0), 50);
  }
  else
  {
    colorWipe(strip.Color(255, 255, 255), 50);
  }
 
}

void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}

long microsecondsToCentimeters(long microseconds)
{
  // The speed of sound is 340 m/s or 29 microseconds per
  // centimeter. The ping travels out and back, so to find
  //the distance of the object we take half of the distance
  //travelled.
  return microseconds / 29 / 2;
}

long microsecondsToInches(long microseconds)
{
// According to Parallax's datasheet for the PING))), there are
// 73.746 microseconds per inch (i.e. sound travels at
//1130 feet per second).  This gives the distance travelled
//by the ping, outbound and return, so we divide by 2 to get the
//distance of the obstacle.
//See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
  return microseconds / 74 / 2;
}