Arduino Ultrasonic Sensor distance calculater program fail

Projects Programming
1

Hello,
I keep getting error of this program. The program is, if I push the button, the Ultrasonic Sensor will start to work and the Arduino will calculate the distance. I found this program in internet, but it won't work. Can someone help me? I'm new on this, thank you so much and sorry for my bad English.

/* HC-SR04 Ultrasonic Sensor

   This sketch reads a HC-SR04 ultrasonic rangefinder and returns the
   distance to the closest object in range. To do this, it sends a pulse
   to the sensor to initiate a reading, then listens for a pulse
   to return.  The length of the returning pulse is proportional to
   the distance of the object from the sensor.

   The circuit:
	* Vcc connection of the HC-SR04 attached to +5V
	* GND connection of the HC-SR04 attached to ground
	* Echo connection of the HC-SR04 attached to digital pin 3
	* Trig connection of the HC-SR04 attached to digital pin 2
 */
// this constant won't change.  It's the pin number
// of the sensor's output:
const int TrigPin = 2;
const int EchoPin = 3;
const int buttonPin = 2;     // the number of the pushbutton pin
int buttonState = 0;         // variable for reading the pushbutton status

long startTime ;                  
long elapsedTime ;                  // elapsed time for stop watch
int fractional;                     // variable used to store fractional part of time
long microsecondsToCentimeters;
long microseconds;

void setup() {
  // initialize serial communication:
  Serial.begin(9600);
  pinMode(buttonPin, INPUT);     
}

void loop()
{
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH) {
  }
  else{
  // establish variables for duration of the ping,
  // and the distance result in centimeters:
  long duration, cm;

  // The HC-SR04 is triggered by a HIGH pulse of 2 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  pinMode(TrigPin, OUTPUT);
  digitalWrite(TrigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(TrigPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(TrigPin, LOW);

  // The same pin is used to read the signal from the HC-SR04: a HIGH
  // pulse whose duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(EchoPin, INPUT);
  duration = pulseIn(EchoPin, HIGH);

  // convert the time into a distance
  cm = microsecondsToCentimeters(duration);

  Serial.print(cm);
  Serial.print("cm");
  Serial.println();

  delay(100);
}

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;
}
}
2

Does that even compile?
There look to be too many closing braces

3

No,it can't compile at all and I don't know what is wrong with the program, I think it have the right logic in it (or isn't it?), but have syntax error. I don't know how to fix it...but anyway, thank for your help!

4

and a few errors more,

this compiles:

/* HC-SR04 Ultrasonic Sensor
 
 This sketch reads a HC-SR04 ultrasonic rangefinder and returns the
 distance to the closest object in range. To do this, it sends a pulse
 to the sensor to initiate a reading, then listens for a pulse
 to return.  The length of the returning pulse is proportional to
 the distance of the object from the sensor.
 
 The circuit:
 	* Vcc connection of the HC-SR04 attached to +5V
 	* GND connection of the HC-SR04 attached to ground
 	* Echo connection of the HC-SR04 attached to digital pin 3
 	* Trig connection of the HC-SR04 attached to digital pin 2
 */
// this constant won't change.  It's the pin number
// of the sensor's output:
const int TrigPin = 2;
const int EchoPin = 3;
const int buttonPin = 2;     // the number of the pushbutton pin
int buttonState = 0;         // variable for reading the pushbutton status

long startTime ;                  
long elapsedTime ;                  // elapsed time for stop watch
int fractional;                     // variable used to store fractional part of time
long microseconds;

void setup() 
{
  // initialize serial communication:
  Serial.begin(9600);
  pinMode(buttonPin, INPUT);     
}

void loop()
{
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH) 
  {
  }
  else
  {
    // establish variables for duration of the ping,
    // and the distance result in centimeters:
    long duration, cm;

    // The HC-SR04 is triggered by a HIGH pulse of 2 or more microseconds.
    // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
    pinMode(TrigPin, OUTPUT);
    digitalWrite(TrigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(TrigPin, HIGH);
    delayMicroseconds(5);
    digitalWrite(TrigPin, LOW);

    // The same pin is used to read the signal from the HC-SR04: a HIGH
    // pulse whose duration is the time (in microseconds) from the sending
    // of the ping to the reception of its echo off of an object.
    pinMode(EchoPin, INPUT);
    duration = pulseIn(EchoPin, HIGH);

    // convert the time into a distance
    cm = microsecondsToCentimeters(duration);

    Serial.print(cm);
    Serial.print("cm");
    Serial.println();

    delay(100);
  }
}

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;
}
5

wow! Thank you so much! I will test it out first, once again. Thank a lot*!!!*