Ultrasonic distance Sensor
Ultrasonic distance Sensor skickar ut ultraljudvågor som sen studsar de tillbaka och tas upp av en annan apparat som bestämmer avståndet.
Jag använde mig av block kod och sen byte jag över det till vanlig kod och den blev så här:
/*
Ping))) Sensor
This sketch reads a PING))) ultrasonic rangefinder and returns the distance
to the closest object in range. To do this, it sends a pulse to the sensor to
initiate a reading, then listens for a pulse to return. The length of the
returning pulse is proportional to the distance of the object from the sensor.
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
// 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;
}
Koden fungerade och då kunde jag se avståndet.