Atmega32 und Mikroe distance meter 2 proto

#define F_CPU 8000000UL

#include <util/delay.h>

#include <avr/io.h>

#include <stdint.h>

#include <time.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <avr/interrupt.h>

using namespace std;

class LCD {

  private:

  void inline toggleEN();

  public:

  void init();

  void writeOut( char *);

  void command(char *);

  void printOut( char *);

};

void LCD::toggleEN() {

  PORTB |= (1<<3);

  _delay_us(50);

  PORTB &= ~(1<<3);

}

void LCD::printOut( char *printChar) {

  PORTB &= 0x0F;

  PORTB |= ((*printChar & 0xF0));

  this->toggleEN();

  _delay_ms(2);

  PORTB &= (0x0F);

  PORTB |= ((*printChar<<4));

  this->toggleEN();

  _delay_ms(2);

}

void LCD::command(char *cmd) {

  PORTB &= 0x00;

  this->printOut(cmd);

  _delay_ms(2);

}

void LCD::writeOut( char *str) {

  PORTB &= 0x00;

  PORTB |= (1<<2);

  int i = 0;

  int len = strlen(str);

  for (i = 0; i < len ; i++)  {

    this->printOut(&str[i]);

  }

}

void LCD::init() {

  DDRB = 0xFF;

  PORTB = 0x00;

  _delay_ms(15);

  PORTB |= (1<<4);

  PORTB |= (1<<5);

  this->toggleEN();

  _delay_ms(5);

  this->toggleEN();

  _delay_us(200);

  this->toggleEN();

  PORTB &= ~(1<<4);

  this->toggleEN();

  PORTB = 0x00;

  PORTB |= (1<<5);

  this->toggleEN();

  PORTB = 0x00;

  PORTB |= (1<<6);

  PORTB |= (1<<7);;

  this->toggleEN();

  _delay_us(40);

  PORTB = 0x00;

  this->toggleEN();

  PORTB |= (1<<6);

  PORTB |= (1<<7);

  this->toggleEN();

  _delay_us(40);

  PORTB = 0x00;

  this->toggleEN();

  PORTB |= (1<<4);

  this->toggleEN();

  _delay_us(40);

  _delay_ms(2);

  PORTB = 0x00;

  this->toggleEN();

  PORTB |= (1<<4);

  this->toggleEN();

  _delay_us(40);

  _delay_ms(2);

  PORTB = 0x00;

}

unsigned int timeMeasurementOFCounter = 0;

uint8_t pwmCounter = 0;

uint8_t adcVal = 0;

uint16_t timerVal = 0;

int main(void) {

  unsigned int distance = 0;

  //LCD

  LCD lcd;

  lcd.init();

  //ADC Init

  ADMUX = (1<<REFS0); // Voltage reference to AVCC

  ADCSRA |= ((1<<ADPS1) | (1<<ADPS2) | (1<<ADPS0));  //Prescaler (128)

  ADCSRA |= (1<<ADIE);  //activate Conversion complete interrupt

  ADMUX |= (1<<ADLAR);  // left adjust result

  //ADCSRA |= (1<<ADEN); //enable adc

  //ADCSRA |= (1<<ADSC); //start first conversion

  OCR2 = 155;

  sei();

  char clear = 0x02;

  //Enable interrupts (Overflow Timer2, Overflow Timer1, CompareMatchInterrupt Timer2)

  TIMSK |= (1<< TOIE2);

  TIMSK |= (1<<OCIE2);

  TIMSK |= (1<<TOIE1);

  //Init Timer2 (Fast PWM-Mode, no prescaler, non inverting mode, inverted Fast PWM PIN 3)

  TCCR2 |= (1<<COM21);

  TCCR2 |= (1<<WGM21);

  TCCR2 |= (1<<WGM20);

  DDRD |= (1<<PD7);

  DDRD |= (1<<PD3);

//  PORTD |= (1<<PD3);

  //Start PWM/Timer2

  TCCR2 |= (1<<CS20);

  while (true) {

    if(adcVal>100) {

      timerVal = TCNT1;

      distance = (int) ((double) 0.00214375 * timerVal); //Zeitberechnung: Schallgeschw. 343 m/s * 0,000000125 s (Zeit für einen Takt bei 8MHz) * 100 (für zentimeter) / 2 (für doppelten weg, hin und zurück) * timerVal (gemssene Takte)

      TCCR2 |= (1<<CS20);

      ADCSRA &= ~(1<<ADEN);

      TCCR1B &= ~(1<<CS10);

      TCNT1 = 0;      

    }

    else {

      distance = 0;

    }

    lcd.command(&clear);

    char temp[16];

    char text[16];

    dtostrf(distance, 3, 0, temp);

    sprintf(text, "Distance: %s cm", temp);

    lcd.writeOut(text);

    _delay_ms(300);

  }

}

ISR (TIMER1_OVF_vect) {

  pwmCounter = 0;

  TCCR2 |= (1<<CS20);

  ADCSRA &= ~(1<<ADEN);

}

ISR (TIMER2_OVF_vect) {

  TCNT2 = 55;

  PORTD ^= (1<<PD3);

}

ISR (TIMER2_COMP_vect) {

  pwmCounter++;

  if(pwmCounter == 4) {

    TCCR2 &= ~(1<<CS20);

    ADCSRA |= (1<<ADEN);

    ADCSRA |= (1<<ADSC);

    TCCR1B |= (1<<CS10);

    pwmCounter = 0;

  }

}

ISR (ADC_vect) {

  adcVal = ADCH;

}