PWM Initialisierung beeinflusst externe Interrupts

#include <avr/io.h>    #include <util/delay.h>

#include <stdlib.h>

#include <avr/interrupt.h>

#include "uart.h"

uint16_t counter_l=0,counter_r=0;

char s[10];

void PWM_Init(void){

    TCCR3A = (1<<WGM30)|(1<<COM3A1)|(1<<COM3B1);

    TCCR3B = (1<<WGM32)|(1<<CS31);

}

ISR(INT2_vect)

{

    counter_l++;

    uart_puts("Left: ");

    uart_puts(itoa( counter_l, s, 10 ) );

    uart_puts("Right: ");

    uart_puts(itoa( counter_r, s, 10 ) );

    uart_putc('\n');

}

ISR(INT3_vect)

{

    counter_r++;

    uart_puts("Left: ");

    uart_puts(itoa( counter_l, s, 10 ) );

    uart_puts("Right: ");

    uart_puts(itoa( counter_r, s, 10 ) );

    uart_putc('\n');

}

void interrupt_init(void){

    DDRD &= ~(1<<2);

    DDRD &= ~(1<<3);

    EICRA = (1<<ISC21)|(1<<ISC31);            //falling edge detection for ext.int2,ext.int3

    EIMSK = (1<<INT2)|(1<<INT3);            //turn on ext.int2,ext.int3

    sei();

}

int main(void){

    //OUTPUTS

    DDRE |= (1<<3);    //Motor ? PWM

    DDRE |= (1<<4);    //Motor ? PWM

    //Pre Settings

    //PWM_Init();

    uart_init();

    interrupt_init();

    //OCR3A=0;

    //OCR3B=0;

    while(1){

    }

    return 0;

}