Code for 2 or 4 ultrasonic hc-sr04

Hi Guys just starting here
I am making an R2D2 with arduino
my idea is to put on it 4 ultrasonic sensor hc-sr04
I got the code for one sensor and I am modifying it for 2 sensor
as result the LEFT sensor works and the Right sensor not.
Can you help please?
Thanks
the code:

/*
HC-SR04 Ping distance sensor:
VCC to arduino 5v
GND to arduino GND
Echo to Arduino pin 7
Trig to Arduino pin 8

This sketch originates from Virtualmix: TrollMaker.com is for sale | HugeDomains
Has been modified by Winkle ink here: Winkleink - box of wires: Arduino - HC-SR04 ultrasonic distance sensor
And modified further by ScottC here: http://arduinobasics.blogspot.com/
on 10 Nov 2012.
*/

//sensor lx
#define echoPin1 7 // Echo Pin lx
#define trigPin1 6 // Trigger Pin lx

//sensor rx
#define echoPin2 5 // Echo Pin dx
#define trigPin2 4 // Trigger Pin dx

#define LEDPin 13 // Onboard LED

int maximumRangelx = 300; // Maximum range needed
int minimumRangelx = 0; // Minimum range needed
long durationlx, distancelx; // Duration used to calculate distance

int maximumRangerx = 300; // Maximum range needed
int minimumRangerx = 0; // Minimum range needed
long durationrx, distancerx; // Duration used to calculate distance

void setup() {
Serial.begin (9600);
pinMode(trigPin1, OUTPUT);
pinMode(echoPin1, INPUT);
pinMode(trigPin2, OUTPUT);
pinMode(echoPin2, INPUT);

pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

void loop() {
/* The following trigPin/echoPin cycle is used to determine the
distance of the nearest object by bouncing soundwaves off of it. */
digitalWrite(trigPin1, LOW);
delayMicroseconds(2);

digitalWrite(trigPin2, LOW);
delayMicroseconds(2);

digitalWrite(trigPin1, HIGH);
delayMicroseconds(10);

digitalWrite(trigPin2, HIGH);
delayMicroseconds(10);

digitalWrite(trigPin1, LOW);
digitalWrite(trigPin2, LOW);

durationlx = pulseIn(echoPin1, HIGH);
durationrx = pulseIn(echoPin2, HIGH);

//Calculate the distance (in cm) based on the speed of sound.
distancelx = durationlx/58.2;
distancerx = durationrx/58.2;

if (distancelx >= maximumRangelx || distancelx <= minimumRangelx){
/* Send a negative number to computer and Turn LED ON
to indicate "out of range" */
Serial.print("LX -1");
digitalWrite(LEDPin, HIGH);

}

else {
/* Send the distance to the computer using Serial protocol, and
turn LED OFF to indicate successful reading. */
Serial.print(distancelx);
Serial.print( " cm");
// digitalWrite(LEDPin, LOW);

}
if (distancerx >= maximumRangerx || distancerx <= minimumRangerx){
/* Send a negative number to computer and Turn LED ON
to indicate "out of range" */
Serial.println(" RX -1");
// digitalWrite(LEDPin, HIGH);

}
else {
/* Send the distance to the computer using Serial protocol, and
turn LED OFF to indicate successful reading. */
Serial.print(distancerx);
Serial.print( " cm");
//digitalWrite(LEDPin, LOW);
}

//Delay 50ms before next reading.
delay(25);
}

Don't trigger the second sender until you get the echo from the first one:

/*
 HC-SR04 Ping distance sensor:
 VCC to arduino 5v 
 GND to arduino GND
 Echo to Arduino pin 7 
 Trig to Arduino pin 8
 
 This sketch originates from Virtualmix: http://goo.gl/kJ8Gl
 Has been modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html
 And modified further by ScottC here: http://arduinobasics.blogspot.com/
 on 10 Nov 2012.
 */


//sensor lx
#define echoPin1 7 // Echo Pin lx
#define trigPin1 6 // Trigger Pin lx

//sensor rx
#define echoPin2 5 // Echo Pin dx
#define trigPin2 4 // Trigger Pin dx

#define LEDPin 13 // Onboard LED


int maximumRangelx = 300; // Maximum range needed
int minimumRangelx = 0; // Minimum range needed
long durationlx, distancelx; // Duration used to calculate distance

int maximumRangerx = 300; // Maximum range needed
int minimumRangerx = 0; // Minimum range needed
long durationrx, distancerx; // Duration used to calculate distance

void setup() {
  Serial.begin (9600);
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);  
  
  pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

void loop() {
  //Calculate the distance (in cm) based on the speed of sound.
  durationlx = readHC-SR04(trigPin1, echoPin1)/58.2;
  durationrx = readHC-SR04(trigPin2, echoPin2)/58.2;

  if (distancelx >= maximumRangelx || distancelx <= minimumRangelx){
    /* Send a negative number to computer and Turn LED ON 
     to indicate "out of range" */
    Serial.print("LX -1");
    digitalWrite(LEDPin, HIGH); 
  }  
  
  else {
    /* Send the distance to the computer using Serial protocol, and
     turn LED OFF to indicate successful reading. */
    Serial.print(distancelx);
    Serial.print( "  cm");
   // digitalWrite(LEDPin, LOW); 
}
  if (distancerx >= maximumRangerx || distancerx <= minimumRangerx){
    /* Send a negative number to computer and Turn LED ON 
     to indicate "out of range" */
    Serial.println("   RX -1");
   // digitalWrite(LEDPin, HIGH); 
    
  }
  else {
    /* Send the distance to the computer using Serial protocol, and
     turn LED OFF to indicate successful reading. */
    Serial.print(distancerx);
    Serial.print( "  cm");
    //digitalWrite(LEDPin, LOW); 
  }

  //Delay 50ms before next reading.
  delay(25);
}

unsigned long readHC-SR04(int triggerPin, int echoPin)
  digitalWrite(triggerPin, LOW); 
  delayMicroseconds(2); 
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10); 
  digitalWrite(triggerPin, LOW);
  return pulseIn(echoPin, HIGH);
}

Hi, first thanks
then I am sorry I didn't get it
If I use your code that I guess I should modify for my case, I get an error here:

void loop() {
//Calculate the distance (in cm) based on the speed of sound.
durationlx = readHC-SR04(trigPin1, echoPin1)/58.2;
durationrx = readHC-SR04(trigPin2, echoPin2)/58.2;

this is the error:

In function 'void loop()':
sketch_jul04c:46: error: 'readHC' was not declared in this scope
sketch_jul04c:46: error: 'SR04' was not declared in this scope
sketch_jul04c.ino: At global scope:
sketch_jul04c:82: error: expected initializer before '-' token
sketch_jul04c:84: error: expected constructor, destructor, or type conversion before '(' token
sketch_jul04c:85: error: expected constructor, destructor, or type conversion before '(' token

and I see you add the last part on the code.
Please give me info
Thanks

Sorry, I forgot that '-' is not a legal identifier character.

/*
 HC-SR04 Ping distance sensor:
 VCC to arduino 5v 
 GND to arduino GND
 Echo to Arduino pin 7 
 Trig to Arduino pin 8
 
 This sketch originates from Virtualmix: http://goo.gl/kJ8Gl
 Has been modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html
 And modified further by ScottC here: http://arduinobasics.blogspot.com/
 on 10 Nov 2012.
 */


//sensor lx
#define echoPin1 7 // Echo Pin lx
#define trigPin1 6 // Trigger Pin lx

//sensor rx
#define echoPin2 5 // Echo Pin dx
#define trigPin2 4 // Trigger Pin dx

#define LEDPin 13 // Onboard LED


int maximumRangelx = 300; // Maximum range needed
int minimumRangelx = 0; // Minimum range needed
long durationlx, distancelx; // Duration used to calculate distance

int maximumRangerx = 300; // Maximum range needed
int minimumRangerx = 0; // Minimum range needed
long durationrx, distancerx; // Duration used to calculate distance

void setup() {
  Serial.begin (9600);
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);  
  
  pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

void loop() {
  //Calculate the distance (in cm) based on the speed of sound.
  durationlx = readHC-SR04(trigPin1, echoPin1)/58.2;
  durationrx = readHC-SR04(trigPin2, echoPin2)/58.2;

  if (distancelx >= maximumRangelx || distancelx <= minimumRangelx){
    /* Send a negative number to computer and Turn LED ON 
     to indicate "out of range" */
    Serial.print("LX -1");
    digitalWrite(LEDPin, HIGH); 
  }  
  
  else {
    /* Send the distance to the computer using Serial protocol, and
     turn LED OFF to indicate successful reading. */
    Serial.print(distancelx);
    Serial.print( "  cm");
   // digitalWrite(LEDPin, LOW); 
}
  if (distancerx >= maximumRangerx || distancerx <= minimumRangerx){
    /* Send a negative number to computer and Turn LED ON 
     to indicate "out of range" */
    Serial.println("   RX -1");
   // digitalWrite(LEDPin, HIGH); 
    
  }
  else {
    /* Send the distance to the computer using Serial protocol, and
     turn LED OFF to indicate successful reading. */
    Serial.print(distancerx);
    Serial.print( "  cm");
    //digitalWrite(LEDPin, LOW); 
  }

  //Delay 50ms before next reading.
  delay(25);
}

unsigned long readHC-SR04(int triggerPin, int echoPin)
  digitalWrite(triggerPin, LOW); 
  delayMicroseconds(2); 
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10); 
  digitalWrite(triggerPin, LOW);
  return pulseIn(echoPin, HIGH);
}

Hi, no I did delete "-" already but it is not just that
I am going to read about the command "read".
But if you get the mistake please let me know because I would like to use 4 sensor.
I have modified my script moving the code order after your suggestion and it works.
please run it there is just a small issue I think because timing.

New code: (btw I am on Mac and I can't paste the code like you do!!!)

/*
HC-SR04 Ping distance sensor:
VCC to arduino 5v
GND to arduino GND
Echo to Arduino pin 7
Trig to Arduino pin 8

This sketch originates from Virtualmix: TrollMaker.com is for sale | HugeDomains
Has been modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html
And modified further by ScottC here: http://arduinobasics.blogspot.com/
on 10 Nov 2012.
*/

//sensor lx
#define echoPin1 7 // Echo Pin lx
#define trigPin1 6 // Trigger Pin lx

//sensor rx
#define echoPin2 5 // Echo Pin dx
#define trigPin2 4 // Trigger Pin dx

#define LEDPin 13 // Onboard LED

int maximumRangelx = 200; // Maximum range needed
int minimumRangelx = 0; // Minimum range needed

int maximumRangerx = 200; // Maximum range needed
int minimumRangerx = 0; // Minimum range needed
long durationlx, distancelx; // Duration used to calculate distance
long durationrx, distancerx; // Duration used to calculate distance

void setup() {
Serial.begin (9600);
pinMode(trigPin1, OUTPUT);
pinMode(echoPin1, INPUT);
pinMode(trigPin2, OUTPUT);
pinMode(echoPin2, INPUT);

pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

void loop() {
/* The following trigPin/echoPin cycle is used to determine the
distance of the nearest object by bouncing soundwaves off of it. */
digitalWrite(trigPin1, LOW);
delayMicroseconds(2);

digitalWrite(trigPin1, HIGH);
delayMicroseconds(10);

digitalWrite(trigPin1, LOW);
durationlx = pulseIn(echoPin1, HIGH);
//Calculate the distance (in cm) based on the speed of sound.
distancelx = durationlx/58.2;

if (distancelx >= maximumRangelx || distancelx <= minimumRangelx){
/* Send a negative number to computer and Turn LED ON
to indicate "out of range" */
Serial.print(" -1 LX ");
//digitalWrite(LEDPin, HIGH);

}

else {
/* Send the distance to the computer using Serial protocol, and
turn LED OFF to indicate successful reading. */
Serial.print(distancelx);
Serial.println( " cm LX ");
// digitalWrite(LEDPin, LOW);

}
delay(25);

digitalWrite(trigPin2, LOW);
delayMicroseconds(2);

digitalWrite(trigPin2, HIGH);
delayMicroseconds(10);

digitalWrite(trigPin2, LOW);
durationrx = pulseIn(echoPin2, HIGH);
//Calculate the distance (in cm) based on the speed of sound.
distancerx = durationrx/58.2;

if (distancerx >= maximumRangerx || distancerx <= minimumRangerx){
/* Send a negative number to computer and Turn LED ON
to indicate "out of range" */
Serial.println(" -1 RX ");
// digitalWrite(LEDPin, HIGH);

}
else {
/* Send the distance to the computer using Serial protocol, and
turn LED OFF to indicate successful reading. */
Serial.print(distancerx);
Serial.println( " cm RX ");
//digitalWrite(LEDPin, LOW);
}

//Delay 50ms before next reading.
delay(25);
}