Arduino with Ping))Ultrasonic Sensor!!

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi, I am trying to use 2 Ping))Ultrasonic sensor with 1 Arduino.

When I connect only 1 sensor, it works perfectly. However, with two sensors, it seems to work, but the second sensor only gives 0 inches and 0 centimeters.

I used the provided code for the Ping sensor, and I set another pin for the other sensor and copy and paste the code with different variables.

I don't know why it does not work. Can anyone help me?

Thanks in advance.

This is what I have so far...

// this constant won't change. It's the pin number
// of the sensor's output:
int pingPin_sen1 = 7;
int pingPin_sen2 = 8;

void setup() {
// initialize serial communication:
Serial.begin(9600);
//Serial.print("Want to Park(1) or Get Your Car Back(2)? : ");
}

void loop()
{
// establish variables for duration of the ping,
// and the distance result in inches and centimeters:
long duration_sen1, inches_sen1, cm_sen1;
long duration_sen2, inches_sen2, cm_sen2;

// 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_sen1, OUTPUT); pinMode(pingPin_sen2, OUTPUT);
digitalWrite(pingPin_sen1, LOW); digitalWrite(pingPin_sen2, LOW);
delayMicroseconds(2);
digitalWrite(pingPin_sen1, HIGH); digitalWrite(pingPin_sen2, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin_sen1, LOW); digitalWrite(pingPin_sen2, 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_sen1, INPUT);
duration_sen1 = pulseIn(pingPin_sen1, HIGH, 1000);
inches_sen1 = microsecondsToInches(duration_sen1);
cm_sen1 = microsecondsToCentimeters(duration_sen1);

pinMode(pingPin_sen2, INPUT);
duration_sen2 = pulseIn(pingPin_sen2, HIGH, 1000);
inches_sen2 = microsecondsToInches(duration_sen2);
cm_sen2 = microsecondsToCentimeters(duration_sen2);

Serial.print(inches_sen1);
Serial.print("in_sen1, ");
Serial.print(cm_sen1);
Serial.print("cm_sen1, ");
Serial.print(inches_sen2);
Serial.print("in_sen2, ");
Serial.print(cm_sen2);
Serial.print("cm_sen2, ");
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;
}

2

Does it work any better if you fire and read one sensor, then fire and read the other sensor?

3

Maybe it would work when you delay the second sensor at another time?

And it might help if you use the code like this? Under each other, remember the arduino reads from top to bottom...

 pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin, LOW);

 pinMode(pingPin2, OUTPUT);
  digitalWrite(pingPin2, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin2, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin2, LOW);

Anyway im a noob so this is only my 2cents, i having a fistfight with my ping sensor in another thread :wink: