how change parralax ping code with hc-sr04.
code:
/*
RC Car + Ping sensor code
*/
// this constant won't change. It's the pin number
// of the sensor's output:
const int pingPin = 7;
const int fowardPin = 13;
const int backwardPin = 12;
const int rightPin = 11;
const int leftPin = 10;
void setup() {
// initialize serial communication:
Serial.begin(9600);
Serial.println("Motor test!");
pinMode(fowardPin, OUTPUT);
pinMode(backwardPin, OUTPUT);
pinMode(leftPin, OUTPUT);
pinMode(rightPin, OUTPUT);
}
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);
if (inches > 10) {
digitalWrite(fowardPin, HIGH);
}
else {
Serial.println("stop");
digitalWrite(fowardPin, LOW);
delay(500);
Serial.println("backup");
digitalWrite(backwardPin, HIGH);
digitalWrite(rightPin, HIGH);
delay(3000);
digitalWrite(backwardPin, LOW);
digitalWrite(rightPin, LOW);
}
}
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;
}