/* This example code is in the public domain.n The circuit: * +V connection of the PING))) attached to +5V * GND connection of the PING))) attached to ground * SIG connection of the PING))) attached to digital pin 7 http://www.arduino.cc/en/Tutorial/Ping */ // this constant won't change. It's the pin number // of the sensor's output: const byte pingPin = 13; const byte pinginPin = 12; const byte displayPin = 6; float cmf = 0.0; 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); pinMode(pinginPin, INPUT); 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(pinginPin, HIGH); // convert the time into a distance // inches = microsecondsToInches(duration); cm = microsecondsToCentimeters(10 * duration); cmf = 22.2 + cm/10 ; // Serial.print(inches); // Serial.print("in, "); Serial.print(cmf); Serial.print("cm"); Serial.println(); analogWrite(displayPin,cmf); delay(1000); } 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; }