core13: An Arduino core for the Attiny13 *testers wanted*

Using Arduino Microcontrollers
182

I just found this servo example on Avrfreaks.net.

ATTiny13 @ 9,6MHz

Drawbacks: only 100 steps, and only one servo

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

//http://www.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=74861&start=0
volatile unsigned int Tick;   // 100KHz pulse 
volatile unsigned int sPulse;   // Servo pulse variable 
volatile unsigned int Tick_20ms;   // Servo frame variable 

void setup() {  

  OSCCAL=0x68;
  pinMode(4,OUTPUT);
  pinMode(3,INPUT);
  cli();
  TCNT0 = 0;
  TCCR0A=0;
  TCCR0B=0;

  TCCR0A |= (1<<WGM01); // Configure timer 1 for CTC mode 
  TIMSK0 |= (1<<OCIE0A); // Enable CTC interrupt 
  TCCR0B |= (1<<CS00); // No prescaler 
  OCR0A = 95; // Set CTC compare value 
  sei(); //  Enable global interrupts 
  Tick = 0; 
  sPulse = 100; 
  Tick_20ms = 0; 
}


void loop() 
{ 
  //int val=analogRead(3); //use potmeter on PB3
  //sPulse=50+(val/10);

  for(int x=50;x<150;x++){

    sPulse=x;
    _delay_ms( 5 );
  }

  for(int x=149;x>=50;x--){

    sPulse=x;
    _delay_ms( 5 );
  }


} 



ISR(TIM0_COMPA_vect)   // 100 KHz interrupt frequency 
{ 
  if(Tick >= 2000)   // One servo frame (20ms) completed 
  { 
    Tick = 0; 
    Tick_20ms = Tick_20ms + 1; 
  } 

  Tick = Tick + 1; 
  if(Tick <= sPulse)   // Generate servo pulse 
  { 
    PORTB |= (1<<PB4);   // Servo pulse high 
  } 
  else 
  { 
    PORTB &= ~(1<<PB4);   // Servo pulse low 
  } 
}