Pushup Counter, helps with stay-at-home training!

/* PUSH UP COUNTER
BY: Kyle Glerum

An ultrasonic sensor measures the distance between you and your head, if the distance is larger than 20 cm a rgb-led will shine red,
if the distance is between 10 and 20 cm, it turns magenta
and if it is less than 10 cm it turns blue, and a point appears on a lcd screen.
Every ten pushups it makes a sound.
You can reset the score with the push of a button.
 */
 
#include <LiquidCrystal.h> // include LCD library

#define BLUE 12 // define RGB-led pins
#define RED 10

const int trigPin = 8; //set pins for the ultrasonic sensor, button and buzzer
const int echoPin = 9;
const int buttonPin = A0;
const int b = 13;

long duration; // set integers
int distance;
int i;
int buttonState = 0;
int x = 1;
int y = 1;

LiquidCrystal lcd(6, 7, 2, 3, 4, 5); // set lcd pins

void setup() {
  Serial.begin(9600); // begin in 9600 baud 
  
  pinMode(trigPin, OUTPUT); //set pin modes
  pinMode(echoPin, INPUT);
  pinMode(buttonPin, INPUT);
  pinMode(b, OUTPUT);
  pinMode(RED, OUTPUT);
  pinMode(BLUE, OUTPUT);

  lcd.begin(16, 2); // begin lcd, define scale of lcd (16 places in a row, 2 rows)
  lcd.print("Push Ups:");



}

void loop() {
  digitalWrite(trigPin, HIGH); // send out an ultra sonic sound for 10 microseconds and measure the time it took for the sound to go from the trigpin to the echo pin
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034/2; //convert the time the signal took to travel to distance in cm

  if (distance >= 20) {digitalWrite(RED, HIGH); //configure RGB-led to burn red, magenta or blue depending on distance
                       digitalWrite(BLUE, LOW);}
  if (distance <= 20) {digitalWrite(BLUE, HIGH);}
  if (distance <= 10) {digitalWrite(RED, LOW);}

  if (i == (10 * y) && x == (1 * y)) { //this if statement plays a sound every ten pushups
                 tone(b, 146.8);
                 delay(50);
                 noTone(b);
                 delay(100);
                 tone(b, 146.8);
                 delay(50);
                 noTone(b);
                 delay(50);
                 tone(b, 293.7);
                 delay(100);
                 noTone(b);
                 x ++;
                 y ++;
  }
  else if (distance <= 10) {delay(350);} //this if else statement makes sure that the time between pushup-readings always stay the same
  
  buttonState = digitalRead(buttonPin); //these lines of code resets every integer and the lcd to the original state by the press of a button
  if (buttonState == HIGH) {
    i = 0;
    x = 1;
    y = 1;
    lcd.setCursor(0,1);
    lcd.print("0      "); } 
    
  lcd.setCursor(0, 1); // set cursor on the second row
  
  if (distance <= 10 ) {i ++;} //print a point if a pushup has been done
    lcd.print(i,DEC);                 
         
  while (distance <= 10) { //if the distance stays smaller then ten for a while, this piece of code makes sure that only one point is given for one pushup
      digitalWrite(trigPin, HIGH);
      delayMicroseconds(10);
      digitalWrite(trigPin, LOW);
      duration = pulseIn(echoPin, HIGH);
      distance = duration * 0.034/2;
  delay(100);}
}