NeoPixels controlled by Accelerometer - Gravity Acceleration Bounce

NeoPixelsMPU6050_GravityAccelBounce.ino

/*
  by Der Faq
  modified 1 Mar 2021

  This code is in the public domain
*/

//GND - GND
//VCC - Pin 3
//SDA - Pin A4
//SCL - Pin A5
#define PIN_VCC 3

#include "I2Cdev.h"
#include "MPU6050.h"
#include "Wire.h"

const int mpuAddress = 0x68;  //Puede ser 0x68 o 0x69
MPU6050 mpu(mpuAddress);

int ax, ay, az;

#include <Adafruit_NeoPixel.h>

#define PIN 6 
#define NUMPIXELS 8 

Adafruit_NeoPixel pixels( NUMPIXELS , PIN , NEO_GRB + NEO_KHZ800 );


void setup() {
  pinMode( PIN_VCC , OUTPUT );
  digitalWrite( PIN_VCC , HIGH );
  delay( 100 );
  
  Serial.begin( 115200 );
  Wire.begin();
  mpu.initialize();

  pixels.begin();
  
  Serial.println(mpu.testConnection() ? F("IMU iniciado correctamente") : F("Error al iniciar IMU"));
}

unsigned long int currentTime;
float vel;
float pos;

void loop() {
  mpu.getAcceleration(&ax, &ay, &az);
  float ayf = (ay)/16384.0;

  if( currentTime - millis() > 33 ) {
    currentTime = millis();
    vel = ayf*(0.33) + vel;
    pos = vel*(0.33) + pos;
    if( pos > 100.0 ) { pos = 100.0; vel = -vel*0.8; }
    if( pos < -100.0 ) { pos = -100.0; vel = -vel*0.8; }
  }
  
  int posPixel = (int)((( (pos/10) + 10 )*8)/20);
  if( posPixel == 8 ) posPixel = 7;
  Serial.println( posPixel );

  for( int i = 0 ; i < pixels.numPixels() ; i++ ) {
    ( i == posPixel ) ? pixels.setPixelColor( i ,  pixels.Color( 255 , 0 , 0 ) ) : pixels.setPixelColor( i ,  pixels.Color( 0 , 0 , 0 ) );
  }
  
  pixels.show();
  
}