I'm in trouble using this ultrasonic sensor ( this is the datasheet :-/ http://www.sure-electronics.net/download/DC-SS014_Ver1.0_EN.pdf )
and this is my arduino code
/*
- Ultrasound Sensor Test
*/
int pingPin = 8;
int ledPin =13;
void setup()
{
Serial.begin(9600);
pinMode(ledPin,OUTPUT);
}
void loop(){
long duration, inches, cm;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// We give a short LOW pulse beforehand to ensure a clean HIGH pulse.
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(10);
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);
//delayMicroseconds(1);
duration = pulseIn(pingPin, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
Serial.print(duration);
Serial.print(" microseconds, ");
Serial.print(inches);
Serial.print(" in, ");
Serial.print(cm);
Serial.print(" cm");
Serial.println();
delay(10000);
}
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 this are the returned values trough serial...
(distance is a random nosense number,
and does not vary when real distance between object and sensor vary, real distance between sensor and a obstacle is 20 cm)
9940 microseconds, 67 in, 171 cm
8454 microseconds, 57 in, 145 cm
8358 microseconds, 56 in, 144 cm
5624 microseconds, 38 in, 96 cm
7152 microseconds, 48 in, 123 cm
6172 microseconds, 41 in, 106 cm
5617 microseconds, 37 in, 96 cm
6813 microseconds, 46 in, 117 cm
6065 microseconds, 40 in, 104 cm
5134 microseconds, 34 in, 88 cm
6329 microseconds, 42 in, 109 cm
5995 microseconds, 40 in, 103 cm
9449 microseconds, 63 in, 162 cm
7926 microseconds, 53 in, 136 cm
7564 microseconds, 51 in, 130 cm
could someone help me?
is my code wrong or is my Ultrasound Motion Sensor broken?
Thanks