Bei mir komplierert der Code von stochri, bloß mit etlichen Warnungen. Die lassen sich aber beseitigen:

"This header file is obsolete. Use <avr/interrupt.h>."
#include <avr/signal.h> löschen.

warning: function declaration isn't a prototype
In dem beiden Funktionen fehlt in der Runden Klammer des Funktionskopfes ein void.

warning: pointer targets in passing argument 1 of 'chSerPrint' differ in signedness
In der Funktion 'chSerPrint' das unsigned vom übergebenen Datentyp löschen.

Code:
/************************************************************************

   SERVO Controller for up to 10 Servos

   controlled by serial line
   default: 2400 Baud 8N1
   
   Processor: ATMEGA 8
   CLOCK: 8MHZ, no prescaler set config bits of Atmega 8 correctly !
   
   Compiler: AVR-GCC


   This code is licensed under the GPL.
   You may modify, redistribute the code .. blabla, you know what I mean ...

   Copyright stochri (c.hab@gmx.net) Nov.2005
   
   Warnungen beiseitigt von uwegw

***************************************************************************/
#include <stdlib.h>
#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>

typedef unsigned char byte;

#define SYSCLK 8000000 // timer clock 8Mhz
#define MAXPULSFREQ 500 // 2ms => 500HZ

#define TIMER_MAXPULS SYSCLK/MAXPULSFREQ // Timer1 value for a 2ms Puls

#define MINPULS TIMER_MAXPULS/4  // min pulslength = 0.5ms
#define MAXPULS TIMER_MAXPULS // max pulslength=2ms

// port pin definitions
// you may redefine the pins to suit your application
// tale a look at the interrupt routine and enable the cases for your servo

#define LOW_SERVO0 PORTD&=~(1<<6)
#define HIGH_SERVO0 PORTD|=(1<<6)

#define LOW_SERVO1 PORTB&=~(1<<0)
#define HIGH_SERVO1 PORTB|=(1<<0)

#define LOW_SERVO2 PORTB&=~(1<<1)
#define HIGH_SERVO2 PORTB|=(1<<1)

#define LOW_SERVO3
#define HIGH_SERVO3

#define LOW_SERVO4
#define HIGH_SERVO4

#define LOW_SERVO5
#define HIGH_SERVO5

#define LOW_SERVO6
#define HIGH_SERVO6

#define LOW_SERVO7
#define HIGH_SERVO7

#define LOW_SERVO8
#define HIGH_SERVO8

#define LOW_SERVO9
#define HIGH_SERVO9


uint16_t Pulslength[20]; // array for all delays

/************************************************************************

   SIGNAL(SIG_OVERFLOW1)
   timer1 interrupt, generates the high and low pulses for each servo

***************************************************************************/
SIGNAL(SIG_OVERFLOW1)
{
   static byte servoindex_half=0;

   switch (servoindex_half)
   {
      case 0: HIGH_SERVO0; break;
      case 1: LOW_SERVO0; break;
      case 2: HIGH_SERVO1; break;
      case 3: LOW_SERVO1; break;
      case 4: HIGH_SERVO2; break;
      case 5: LOW_SERVO2; break;
//      case 6: HIGH_SERVO3; break;
//      case 7: LOW_SERVO3; break;
//      case 8: HIGH_SERVO4; break;
//      case 9: LOW_SERVO4; break;
//      case 10: HIGH_SERVO5; break;
//      case 11: LOW_SERVO5; break;
//      case 12: HIGH_SERVO6; break;
//      case 13: LOW_SERVO6; break;
//      case 14: HIGH_SERVO7; break;
//      case 15: LOW_SERVO7; break;
//      case 16: HIGH_SERVO8; break;
//      case 17: LOW_SERVO8; break;
//      case 18: HIGH_SERVO9; break;
//      case 19: LOW_SERVO9; break;
   }

   
   TCNT1 =Pulslength[servoindex_half]; // set time for next interrupt   

    servoindex_half++; // increment timervalue index
   if(servoindex_half==20)servoindex_half=0;   // reset index
}
/************************************************************************

   void setservo(byte index, byte value)

   Set servo position
   value: 0..255

***************************************************************************/

void setservo(byte index, byte value)
{
   uint16_t wert;

   wert=MINPULS+(MAXPULS-MINPULS)/256*value;
   
   // callculate hightime
   Pulslength[index<<1]=0-wert;
   
   // sume of low and hightime for one servo is 2ms
   Pulslength[(index<<1)+1]=0-(TIMER_MAXPULS-wert);
   
   // 10 Servos give you 10*2ms=20ms total cycle time
}

/************************************************************************

   void init_servos()
   
   initialize all Servos to the start position
***************************************************************************/
void init_servos(void)
{
   byte n;
   for(n=0;n<10;n++) setservo(n,128);
}

/************************************************************************

   void init(void)
   initialize the prozessor registers
***************************************************************************/

void init(void)
{
   // prepare RS232
   UCSRA = 0x00;
   UCSRB = 0x00;   
   UCSRC = 0x86; // No Parity | 1 Stop Bit | 8 Data Bit
   UBRRL = 0xCF; // 2400bps @ 8.00MHz
//   UBRRL = 51; // 9600bps @ 8.00MHz
//   UBRRL = 25; // 19200bps @ 8.00MHz

    /* initialize ports */
    DDRB = 0xFF;
    DDRC = 0xFF;
    DDRD = 0xFF;
    PORTB = 0x00;
    PORTC = 0x00;
    PORTD = 0x00;

    // init timer1
   TCNT1 = 0-16000;
   TCCR1A=0;
   TCCR1B=0x01;
    TIMSK |= _BV(TOIE2) | _BV(TOIE1);

    /* allow interrupts */
    sei();
}

/************************************************************************

   serial communication

***************************************************************************/

byte chgetchar(void)
{
   UCSRB = 0x10; // enable receiver
   while(!(UCSRA & 0x80)); // wait for received byte
   return UDR;
}

void chputchar(byte zeichen)
{
   UCSRB = 0x08; // enable transmitter
   UCSRA|=0x40; // clear transmitter flag
   while (!(UCSRA & 0x20)); // wait for empty transmit buffer
   UDR = zeichen;
   while (!(UCSRA & 0x40)); // Wait for transmit complete flac (TXC)
}
void chSerPrint(char *data)
{
   unsigned char i = 0;
   while(data[i]!=0x00) chputchar(data[i++]);
}

/************************************************************************

   main programm

   servo controll by RS232 interface

***************************************************************************/

int main(void)
{
   char c;
   byte n;
   byte servos[10];

   init();
   init_servos();
   
   chSerPrint("\n\r-- Atmega8 servo controller V1.0 --\n\r");
   chSerPrint("Connection OK\n\r");

   while(1)
   {
   
      // get key from terminal
      c=chgetchar();

      if(c=='q') servos[0] += 10;
      if(c=='w') servos[0] -= 10;
      if(c=='a') servos[1] += 10;
      if(c=='s') servos[1] -= 10;
      if(c=='y') servos[2] += 10;
      if(c=='x') servos[2] -= 10;

      // set to default position, if space is pressed
      if(c==' ')
      {
         servos[0] = 128;
         servos[1] = 128;
         servos[2] = 128;
      }

      for(n=0;n<10;n++) setservo(n,servos[n]);
   }
}