Mh, habe jetzt die von euch genannten Punkte geändert und es sieht jetzt so aus:

Code:
#include "RP6ControlLib.h" 		// The RP6 Control Library. 
								// Always needs to be included!
#include "stdlib.h"
#include "avr/io.h"
#include "avr/interrupt.h"

volatile unsigned long timestamp;    // volatile wegen Zugriff im Interrrupt
unsigned int impuls;
unsigned int periode;
unsigned int zeit;
volatile uint8_t flag;
volatile uint8_t position; 
unsigned int wert;
char puffer[5];

void int1(void)  //  Flanke an INT1
{  
	timestamp = TCNT1;
	if (position == 1)
	{
		MCUCR = (0<<ISC10); //fallende Flanke
		position = 0;
	}
	else
	{
		MCUCR = (1<<ISC10); //steigende Flanke
		position = 1;
	}
	flag = 1;
}

int main(void)
{
	initRP6Control();
	initLCD();
	INT1_setEventHandler(int1);
	
	MCUCR = (1<<ICS11) + (1<<ICS10); // Flanke von INT1 einstellen
	GICR = (1<<INT1); // INT1 aktivieren
	TCCR1B = (1<<CS11);		// Prescaler von 8
	sei();
	while(true) 
	{ 
		if (flag == 1)
		{
			flag = 0;
			if (position == 0) 
			{
				periode = timestamp - zeit;
				zeit = timestamp;
				wert = impuls / periode;
				utoa(wert,puffer,4);
				writeStringLCD(puffer);
			}
			else
			{
				impuls = timestamp - zeit;
			}
		}
	}
	return 0;
}
Nach wie vor erhalte ich:

Code:
Beschleunigungssensor.c: In function 'main':
Beschleunigungssensor.c:66: error: 'ICS11' undeclared (first use in this function)
Beschleunigungssensor.c:66: error: (Each undeclared identifier is reported only once
Beschleunigungssensor.c:66: error: for each function it appears in.)
Beschleunigungssensor.c:66: error: 'ICS10' undeclared (first use in this function)
make: *** [Beschleunigungssensor.o] Error 1

> Process Exit Code: 2
> Time Taken: 00:00
Weiß echt nicht warum -.-

Gruß Lee