Rev 694 |
Go to most recent revision |
Blame |
Last modification |
View Log
| RSS feed
#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include "eeprom.h"
#include "analog.h"
#include "main.h"
#include "fc.h"
#include "mm3.h"
volatile uint16_t CountMilliseconds = 0;
volatile uint8_t UpdateMotor = 0;
volatile uint16_t cntKompass = 0;
volatile uint16_t BeepTime = 0;
volatile uint16_t BeepModulation = 0xFFFF;
/*****************************************************/
/* Initialize Timer 0 */
/*****************************************************/
// timer 0 is used for the PWM generation to control the offset voltage at the air pressure sensor
// Its overflow interrupt routine is used to generate the beep signal and the flight control motor update rate
void TIMER0_Init(void)
{
uint8_t sreg = SREG;
// disable all interrupts before reconfiguration
cli();
// configure speaker port as output
if(BoardRelease == 10)
{ // Speaker at PD2
DDRD |= (1<<DDD2);
PORTD &= ~(1<<PORTD2);
}
else
{ // Speaker at PC7
DDRC |= (1<<DDC7);
PORTC &= ~(1<<PORTC7);
}
// set PB3 and PB4 as output for the PWM used as aoffset for the pressure sensor
DDRB |= (1<<DDB4)|(1<<DDB3);
PORTB &= ~((1<<PORTB4)|(1<<PORTB3));
if(BoardRelease == 10)
{
DDRD |= (1<<DDD2);
PORTD &= ~(1<<PORTD2);
}
else
{
DDRC |= (1<<DDC7);
PORTC &= ~(1<<PORTC7);
}
// Timer/Counter 0 Control Register A
// Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)
// Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)
// Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)
TCCR0A &= ~((1<<COM0A0)|(1<<COM0B0));
TCCR0A |= (1<<COM0A1)|(1<<COM0B1)|(1<<WGM01)|(1<<WGM00);
// Timer/Counter 0 Control Register B
// set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz
// i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
// hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
// divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
TCCR0B &= ~((1<<FOC0A)|(1<<FOC0B)|(1<<WGM02));
TCCR0B = (TCCR0B & 0xF8)|(0<<CS02)|(1<<CS01)|(0<<CS00);
// initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4
OCR0A = 0; // for PB3
OCR0B = 120; // for PB4
// init Timer/Counter 0 Register
TCNT0 = 0;
// Timer/Counter 0 Interrupt Mask Register
// enable timer overflow interrupt only
TIMSK0 &= ~((1<<OCIE0B)|(1<<OCIE0A));
TIMSK0 |= (1<<TOIE0);
SREG = sreg;
}
/*****************************************************/
/* Interrupt Routine of Timer 0 */
/*****************************************************/
ISR(TIMER0_OVF_vect) // 9.765 kHz
{
static uint8_t cnt_1ms = 1,cnt = 0;
uint8_t Beeper_On = 0;
if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)
{
cnt = 9;
cnt_1ms++;
cnt_1ms %= 2;
if(!cnt_1ms) UpdateMotor = 1; // every 2nd run (976Hz/2 = 488 Hz)
CountMilliseconds++; // increment millisecond counter
}
// beeper on if duration is not over
if(BeepTime > 1)
{
BeepTime--; // decrement BeepTime
if(BeepTime & BeepModulation) Beeper_On = 1;
else Beeper_On = 0;
}
else // beeper off if duration is over
{
Beeper_On = 0;
BeepModulation = 0xFFFF;
}
// if beeper is on
if(Beeper_On)
{
// set speaker port to high
if(BoardRelease == 10) PORTD |= (1<<PORTD2); // Speaker at PD2
else PORTC |= (1<<PORTC7); // Speaker at PC7
}
else // beeper is off
{
// set speaker port to low
if(BoardRelease == 10) PORTD &= ~(1<<PORTD2);// Speaker at PD2
else PORTC &= ~(1<<PORTC7);// Speaker at PC7
}
// update compass value if this option is enabled in the settings
if(ParamSet.GlobalConfig & CFG_COMPASS_ACTIVE)
{
MM3_timer0(); // read out mm3 board
}
}
// -----------------------------------------------------------------------
uint16_t SetDelay (uint16_t t)
{
return(CountMilliseconds + t + 1);
}
// -----------------------------------------------------------------------
int8_t CheckDelay(uint16_t t)
{
return(((t - CountMilliseconds) & 0x8000) >> 9); // check sign bit
}
// -----------------------------------------------------------------------
void Delay_ms(uint16_t w)
{
unsigned int t_stop;
t_stop = SetDelay(w);
while (!CheckDelay(t_stop));
}
// -----------------------------------------------------------------------
void Delay_ms_Mess(uint16_t w)
{
uint16_t t_stop;
t_stop = SetDelay(w);
while (!CheckDelay(t_stop)) ADC_Enable();
}