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// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// +  POSSIBILITY OF SUCH DAMAGE.
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// +  POSSIBILITY OF SUCH DAMAGE.
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// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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#include <inttypes.h>
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include "main.h"
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#include "main.h"
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volatile unsigned int CountMilliseconds = 0;
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volatile unsigned char Timer0Overflow;
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unsigned int I2C_Timeout = 0;
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unsigned int SIO_Timeout = 0;
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enum {
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  STOP             = 0,
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  CK               = 1,
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  CK8              = 2,
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  CK64             = 3,
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  CK256            = 4,
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  CK1024           = 5,
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  T0_FALLING_EDGE  = 6,
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  T0_RISING_EDGE   = 7
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};
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SIGNAL(SIG_OVERFLOW0)
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{
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 static unsigned char cnt;
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 static unsigned int cmps_cnt;
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 TCNT0 -= 101;  // reload
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 Timer0Overflow++;
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volatile uint16_t CountMilliseconds = 0;
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volatile uint16_t I2C_Timeout = 0;
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/*****************************************************/
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/*              Initialize Timer 0                   */
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/*****************************************************/
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void TIMER0_Init(void)
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{
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        uint8_t sreg = SREG;
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        // disable all interrupts before reconfiguration
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        cli();
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        // set PB2 as output for the PWM used to signal compass heading
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        DDRB |= (1<<DDB2);
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        PORTB &= ~(1<<PORTB2);
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        // Timer/Counter 0 Control Register A
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        // Normal Timer Counter Mode (Bits WGM02 = 0, WGM01 = 0, WGM00 = 0)
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    // OC0A disconnected (Bits COM0A1 = 0, COM0A0 = 0)
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    // OC0B disconnected (Bits COM0B1 = 0, COM0B0 = 0)
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    TCCR0A &= ~((1<<COM0A1)|(1<<COM0A0)|(1<<COM0B1)|(1<<COM0B0)|(1<<WGM01)|(1<<WGM00));
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        // Timer/Counter 0 Control Register B
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        // set clock devider for timer 0 to SYSKLOCK/8 = 8MHz / 8 = 1MHz
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        // i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
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        // hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
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        // divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
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        TCCR0B &= ~((1<<FOC0A)|(1<<FOC0B)|(1<<WGM02)|(1<<CS02));
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    TCCR0B = (1<<CS01)|(0<<CS00);
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        // init Timer/Counter 0 Register
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    TCNT0 = 0;
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        // Timer/Counter 0 Interrupt Mask Register
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        // enable timer overflow interrupt only
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        TIMSK0 &= ~((1<<OCIE0B)|(1<<OCIE0A));
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        TIMSK0 |= (1<<TOIE0);
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        SREG = sreg;
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}
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// -----------------------------------------------------------------------
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 if(++cmps_cnt == 380)
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ISR(TIMER0_OVF_vect)
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{
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        static uint8_t cnt;
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        static uint16_t cmps_cnt;
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        // reload timer register so that overflow occurs after 100 increments at 1 MHz
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        // resulting in a calling rate of this ISR of 10kHz or 0.1 ms.
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        TCNT0 -= 101;
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        // disable PWM when bad compass heading value
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        if(Heading < 0)
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 {
 122 
        {
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  PORTB |= 0x04;
 123 
                PORTB &= ~(PORTB2);
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  cmps_cnt = 0;
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                cmps_cnt = 0;
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 }
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        }
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 else
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 if(cmps_cnt == PwmHeading)
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        else
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        {
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                // if a periode of 38.0 ms is over
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                if(++cmps_cnt >= 380)
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                {
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 {
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                        // set PWM out to high
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                        PORTB |= PORTB2;
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                        // reset periode counter
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                        cmps_cnt = 0;
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                }
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                // if the delay in 0.1 ms is equal to Heading + 10
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                else if(cmps_cnt >= (Heading + 10))
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                {
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                        // set PWM out to low
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                        PORTB &= ~(PORTB2);
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  PORTB &= ~0x04;
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                }
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 }
 142 
        }
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- 
 
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        if(!--cnt)
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 if(!--cnt)
 145 
        {
95 
  {
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                // every 10th run (1kHz or 1ms)
96 
   cnt = 10;
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                cnt = 10;
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   CountMilliseconds += 1;
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   if(I2C_Timeout) I2C_Timeout--;
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                CountMilliseconds++;
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   if(SIO_Timeout) SIO_Timeout--;
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                if(I2C_Timeout) I2C_Timeout--;
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  }
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}
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 150 
        }
103 
 
 - 
 
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void Timer0_Init(void)
 - 
 
105 
{
 - 
 
106 
 TCCR0B = TIMER_TEILER;  // Starten des Timers
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107 
// TCNT0 = 100;  // reload
 - 
 
108 
 TIM0_START;
 - 
 
109 
 TIMER2_INT_ENABLE;
 151 
}
110 
}
 152 
 
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 153 
 
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 154 
// -----------------------------------------------------------------------
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- 
 
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uint16_t SetDelay (uint16_t t)
113 
unsigned int SetDelay(unsigned int t)
 156 
{
114 
{
 157 
  return(CountMilliseconds + t - 1);
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  return(CountMilliseconds + t - 1);                                            
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}
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}
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// -----------------------------------------------------------------------
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int8_t CheckDelay(uint16_t t)
118 
char CheckDelay (unsigned int t)
 162 
{
119 
{
 163 
        return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit
120 
  return(((t - CountMilliseconds) & 0x8000) >> 8);
 164 
}
121 
}
 165 
 
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 166 
// -----------------------------------------------------------------------
- 
 
 167 
void Delay_ms(uint16_t wait)
- 
 
 168 
{
- 
 
 169 
        uint16_t t_stop;
- 
 
 170 
        t_stop = SetDelay(wait);