Arduino实现超声波测距

unsigned int EchoPin=2;
unsigned int TrigPin=3;
unsigned long TimeEcho=0;
unsigned long Len=0;
unsigned long Len1=0;
unsigned long Len2=0;
void setup(){
  Serial.begin(9600);
  pinMode(EchoPin,INPUT);
  pinMode(TrigPin,OUTPUT);
}
void loop(){
  digitalWrite(TrigPin, HIGH);
  delayMicroseconds(50);
  digitalWrite(TrigPin, LOW);
  TimeEcho=pulseIn(EchoPin,HIGH);
  if(TimeEcho<60000 && TimeEcho >1){
    Len=(TimeEcho*34)/2;
    Len1=Len/100;
    Len2=Len%100;
    Serial.print("Present Length is :");
    Serial.print(Len1, DEC);
    Serial.print(".");
    if(Len2<10) Serial.print("0");
    Serial.print(Len2, DEC);
    Serial.println("mm");
  }
   delay(1000);
}