int trigPin = 2; 
int echoPin = 3;

int A = 4; 
int B = 5;
int C = 6;
int D = 7;
int E = 8;
int F = 9;
int G = 10;

 

void setup() {

pinMode(A, OUTPUT); 
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(F, OUTPUT);
  pinMode(G, OUTPUT);
Serial.begin(9600);

}

 

void loop()

{

long duration, inches, cm;

 

pinMode(trigPin, OUTPUT);

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);


pinMode(echoPin, INPUT);

duration = pulseIn(echoPin, HIGH);


inches = microsecondsToInches(duration);

cm = microsecondsToCentimeters(duration);

if (cm == 0)
{
   displayZero();
}

if (inches == 1)
{
  displayOne();
}

if (inches == 2)
{
  displayTwo();
}

if (inches == 3)
{
  displayThree();
}

if (inches == 4)
{
  displayFour();
}

if (inches == 5)
{
  displayFive();
}

if (inches == 6)
{
  displaySix();
}

if (inches == 7)
{
  displaySeven();
}

if (inches == 8)
{
  displayEight();
}

if (inches == 9)
{
  displayNine();
}
  

Serial.print(inches);

Serial.print("in, ");

Serial.print(cm);

Serial.print("cm");

Serial.println();

delay(50);

}

 

long microsecondsToInches(long microseconds)

{

return microseconds / 74 / 2;

}

 

long microsecondsToCentimeters(long microseconds)

{


return microseconds / 29 / 2;

}




void displayZero()
{
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, LOW);
}

void displayOne()
{
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(A,LOW);
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);
}
  
void displayTwo()
{
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(C, LOW);
  digitalWrite(F, LOW);
}

void displayThree()
{
  digitalWrite(F, LOW);
  digitalWrite(A, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(G, HIGH);
}

void displayFour()
{
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(D, LOW);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(E, LOW);
}

void displayFive()
{
  digitalWrite(A, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(D, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(G, HIGH);
}

void displaySix()
{
  digitalWrite(A, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(G, HIGH);
}

void displaySeven()
{
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);
  digitalWrite(E, LOW);
  digitalWrite(D, LOW);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void displayEight()
{
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
}

void displayNine()
{
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(D, LOW);
  digitalWrite(C, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
}