Project 2 - Measuring the distance of an object using ultrasonic sensor and also smoothen the sensor data using moving average filter

(28015 Ping) detects the distance of the closest object in front of the sensor (from 3 cm up to 400 cm). It works by sending out a burst of ultrasound and listening for the echo when it bounces off of an object. It pings the obstacles with ultrasound. The Arduino board sends a short pulse to trigger the detection, then listens for a pulse on the same pin using the pulseIn() function. The duration of this second pulse is equal to the time taken by the ultrasound to travel to the object and back to the sensor. Using the speed of sound, this time can be converted to distance.

## Master##

#include<LiquidCrystal.h> // header file for LCD display
LiquidCrystal lcd(13,12,5,4,3,2);
#include<Wire.h> //header file for

void setup()
{
lcd.begin(16,2);
lcd.setCursor(0,0);
lcd.print("Master");
lcd.setCursor(0,1);
lcd.print("data from slave");
delay(1000);
lcd.clear();
Wire.begin(); // beginning the serial communication
}

void loop()
{
Wire.requestFrom(1,2); // request from slave to receive the master

byte a=Wire.read(); //reading the data from slave
lcd.begin(16,2); //beginning the LCD for printing data
lcd.setCursor(0,0);
lcd.print("Distance");
delay(1000); // delay of 1000 milliseconds
lcd.setCursor(0,1);
lcd.print(a); //printing the distance in centimeter
lcd.print("cm");
delay(1000); // delay of 1000 milliseconds
lcd.clear(); //clearing the content in LCD

byte b=Wire.read(); //reading the data from slave
lcd.begin(16,2); //beginning the LCD for printing data
lcd.setCursor(0,0);
lcd.print("Inches");
delay(1000); // delay of 1000 milliseconds
lcd.setCursor(0,1);
lcd.print(b); //printing the distance in inches
lcd.print("inches");
delay(1000); // delay of 1000 milliseconds
lcd.clear(); //clearing the content in LCD
}

##Slave##

#include<Wire.h>
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: https://www.parallax.com/package/ping-ultrasonic-distance-sensor-downloads/
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;
}