Problem with multiple Parallax PING))) Ultrasonic Sensors - c++

Question

I'm trying to make an AGV(automated guided vehicle) which I wanna use 4 parallax ultrasonic sensors for but there is a problem when I'm using 1 of them its all okay and works perfectly fine, but when I add 1 or more my output on serial monitor says 0cm. I just can't figure it out
I have read lots of forums already but nothing works yet. Here is the code I'm using for 1:
// this constant won't change. It's the pin number of the sensor's output:
const int pingPin = 7;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// establish variables for duration of the ping, and the distance result
// in inches and centimeters:
long duration, inches, cm;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(100);
}
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;
}
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;
}
And here when I use more than 1
// this constant won't change. It's the pin number of the sensor's output:
const int pingPin = 7;
const int pingPin2 = 6;
const int pingPin3 = 5;
const int pingPin4 = 4;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// establish variables for duration of the ping, and the distance result
// in inches and centimeters:
long duration, inches, cm;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
digitalWrite(pingPin2, LOW);
digitalWrite(pingPin3, LOW);
digitalWrite(pingPin4, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
digitalWrite(pingPin2, HIGH);
digitalWrite(pingPin3, HIGH);
digitalWrite(pingPin4, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
digitalWrite(pingPin2, LOW);
digitalWrite(pingPin3, LOW);
digitalWrite(pingPin4, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin, INPUT);
pinMode(pingPin2, INPUT);
pinMode(pingPin3, INPUT);
pinMode(pingPin4, INPUT);
duration = pulseIn(pingPin, HIGH);
duration = pulseIn(pingPin2, HIGH);
duration = pulseIn(pingPin3, HIGH);
duration = pulseIn(pingPin4, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(100);
}
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;
}
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;
}
when I use 1 sensor it gives me the right values like expected and when I use 2 or more sensors the a value of 0cm

Answer 1

thanks i just copy paste the code for a single sensor 4 times after each other and made each of them for another sensor there is just a small delay in each sensor but thats alright. new code is as following:
// this constant won't change. It's the pin number of the sensor's output:
const int pingPin = 7;
const int pingPin2= 6;
const int pingPin3 = 5;
const int pingPin4 = 4;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// establish variables for duration of the ping, and the distance result
// in inches and centimeters:
long duration, inches, cm;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(400);
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin2, OUTPUT);
digitalWrite(pingPin2, LOW);
delayMicroseconds(2);
digitalWrite(pingPin2, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin2, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin2, INPUT);
duration = pulseIn(pingPin2, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(400);
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin3, OUTPUT);
digitalWrite(pingPin3, LOW);
delayMicroseconds(2);
digitalWrite(pingPin3, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin3, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin3, INPUT);
duration = pulseIn(pingPin3, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(400);
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin4, OUTPUT);
digitalWrite(pingPin4, LOW);
delayMicroseconds(2);
digitalWrite(pingPin4, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin4, LOW);
// The same pin is used to read the signal from the PING))): 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(pingPin4, INPUT);
duration = pulseIn(pingPin4, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(400);
}
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;
}
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;
}