#include <SoftwareSerial.h>


const byte rxPin = PA1;
const byte txPin = PA0;

// set up a new serial object
SoftwareSerial mySerial (rxPin, txPin);

// this constant won't change. It's the pin number of the sensor's output:
const int pingPin = PA6;

void setup() {
// initialize serial communication:
mySerial.begin(4800);
}

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(50);
digitalWrite(pingPin, HIGH);
delayMicroseconds(50);
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);


mySerial.println(inches);


mySerial.println();

delay(100);
}

long microsecondsToInches(long microseconds) {
return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds) {
return microseconds / 29 / 2;

}