492 lines
14 KiB
C
492 lines
14 KiB
C
/*! \file timer.c \brief System Timer function library. */
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//*****************************************************************************
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//
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// File Name : 'timer.c'
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// Title : System Timer function library
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// Author : Pascal Stang - Copyright (C) 2000-2002
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// Created : 11/22/2000
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// Revised : 07/09/2003
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// Version : 1.1
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// Target MCU : Atmel AVR Series
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// Editor Tabs : 4
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//
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// This code is distributed under the GNU Public License
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// which can be found at http://www.gnu.org/licenses/gpl.txt
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//
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//*****************************************************************************
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <avr/pgmspace.h>
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#include <avr/sleep.h>
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#include "global.h"
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#include "timer.h"
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#include "rprintf.h"
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// Program ROM constants
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// the prescale division values stored in order of timer control register index
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// STOP, CLK, CLK/8, CLK/64, CLK/256, CLK/1024
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unsigned const short __attribute__ ((progmem)) TimerPrescaleFactor[] = {0,1,8,64,256,1024};
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// the prescale division values stored in order of timer control register index
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// STOP, CLK, CLK/8, CLK/32, CLK/64, CLK/128, CLK/256, CLK/1024
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unsigned const short __attribute__ ((progmem)) TimerRTCPrescaleFactor[] = {0,1,8,32,64,128,256,1024};
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// Global variables
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// time registers
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volatile unsigned long TimerPauseReg;
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volatile unsigned long Timer0Reg0;
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volatile unsigned long Timer2Reg0;
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typedef void (*voidFuncPtr)(void);
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volatile static voidFuncPtr TimerIntFunc[TIMER_NUM_INTERRUPTS];
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// delay for a minimum of <us> microseconds
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// the time resolution is dependent on the time the loop takes
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// e.g. with 4Mhz and 5 cycles per loop, the resolution is 1.25 us
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void delay_us(unsigned short time_us)
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{
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unsigned short delay_loops;
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register unsigned short i;
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delay_loops = (time_us+3)/5*CYCLES_PER_US; // +3 for rounding up (dirty)
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// one loop takes 5 cpu cycles
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for (i=0; i < delay_loops; i++) {};
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}
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/*
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void delay_ms(unsigned char time_ms)
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{
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unsigned short delay_count = F_CPU / 4000;
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unsigned short cnt;
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asm volatile ("\n"
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"L_dl1%=:\n\t"
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"mov %A0, %A2\n\t"
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"mov %B0, %B2\n"
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"L_dl2%=:\n\t"
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"sbiw %A0, 1\n\t"
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"brne L_dl2%=\n\t"
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"dec %1\n\t" "brne L_dl1%=\n\t":"=&w" (cnt)
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:"r"(time_ms), "r"((unsigned short) (delay_count))
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);
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}
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*/
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void timerInit(void)
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{
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u08 intNum;
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// detach all user functions from interrupts
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for(intNum=0; intNum<TIMER_NUM_INTERRUPTS; intNum++)
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timerDetach(intNum);
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// initialize all timers
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timer0Init();
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timer1Init();
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#ifdef TCNT2 // support timer2 only if it exists
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timer2Init();
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#endif
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// enable interrupts
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sei();
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}
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void timer0Init()
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{
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// initialize timer 0
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timer0SetPrescaler( TIMER0PRESCALE ); // set prescaler
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outb(TCNT0, 0); // reset TCNT0
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sbi(TIMSK0, TOIE0); // enable TCNT0 overflow interrupt
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timer0ClearOverflowCount(); // initialize time registers
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}
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void timer1Init(void)
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{
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// initialize timer 1
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timer1SetPrescaler( TIMER1PRESCALE ); // set prescaler
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outb(TCNT1H, 0); // reset TCNT1
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outb(TCNT1L, 0);
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sbi(TIMSK0, TOIE1); // enable TCNT1 overflow
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}
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#ifdef TCNT2 // support timer2 only if it exists
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void timer2Init(void)
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{
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// initialize timer 2
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timer2SetPrescaler( TIMER2PRESCALE ); // set prescaler
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outb(TCNT2, 0); // reset TCNT2
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sbi(TIMSK0, TOIE2); // enable TCNT2 overflow
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timer2ClearOverflowCount(); // initialize time registers
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}
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#endif
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void timer0SetPrescaler(u08 prescale)
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{
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// set prescaler on timer 0
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outb(TCCR0A, (inb(TCCR0A) & ~TIMER_PRESCALE_MASK) | prescale);
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}
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void timer1SetPrescaler(u08 prescale)
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{
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// set prescaler on timer 1
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outb(TCCR1B, (inb(TCCR1B) & ~TIMER_PRESCALE_MASK) | prescale);
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}
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#if (!(defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
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defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
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defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \
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defined(__AVR_AT90USB162__) || defined(__AVR_AT90USB82__) || \
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defined(__AVR_ATmega32U6__) || defined(__AVR_ATmega32U2__)))
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// support timer2 only if it exists, but it is different on the USB AVRs
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void timer2SetPrescaler(u08 prescale)
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{
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// set prescaler on timer 2
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outb(TCCR2, (inb(TCCR2) & ~TIMER_PRESCALE_MASK) | prescale);
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}
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#endif
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u16 timer0GetPrescaler(void)
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{
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// get the current prescaler setting
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return (pgm_read_word(TimerPrescaleFactor+(inb(TCCR0A) & TIMER_PRESCALE_MASK)));
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}
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u16 timer1GetPrescaler(void)
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{
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// get the current prescaler setting
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return (pgm_read_word(TimerPrescaleFactor+(inb(TCCR1B) & TIMER_PRESCALE_MASK)));
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}
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#if (!(defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
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defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
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defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \
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defined(__AVR_AT90USB162__) || defined(__AVR_AT90USB82__) || \
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defined(__AVR_ATmega32U6__) || defined(__AVR_ATmega32U2__)))
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// support timer2 only if it exists, but it is different on the USB AVRs
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u16 timer2GetPrescaler(void)
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{
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//TODO: can we assume for all 3-timer AVR processors,
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// that timer2 is the RTC timer?
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// get the current prescaler setting
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return (pgm_read_word(TimerRTCPrescaleFactor+(inb(TCCR2) & TIMER_PRESCALE_MASK)));
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}
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#endif
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void timerAttach(u08 interruptNum, void (*userFunc)(void) )
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{
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// make sure the interrupt number is within bounds
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if(interruptNum < TIMER_NUM_INTERRUPTS)
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{
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// set the interrupt function to run
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// the supplied user's function
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TimerIntFunc[interruptNum] = userFunc;
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}
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}
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void timerDetach(u08 interruptNum)
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{
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// make sure the interrupt number is within bounds
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if(interruptNum < TIMER_NUM_INTERRUPTS)
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{
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// set the interrupt function to run nothing
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TimerIntFunc[interruptNum] = 0;
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}
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}
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/*
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u32 timerMsToTics(u16 ms)
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{
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// calculate the prescaler division rate
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u16 prescaleDiv = 1<<(pgm_read_byte(TimerPrescaleFactor+inb(TCCR0)));
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// calculate the number of timer tics in x milliseconds
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return (ms*(F_CPU/(prescaleDiv*256)))/1000;
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}
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u16 timerTicsToMs(u32 tics)
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{
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// calculate the prescaler division rate
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u16 prescaleDiv = 1<<(pgm_read_byte(TimerPrescaleFactor+inb(TCCR0)));
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// calculate the number of milliseconds in x timer tics
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return (tics*1000*(prescaleDiv*256))/F_CPU;
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}
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*/
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void timerPause(unsigned short pause_ms)
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{
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// pauses for exactly <pause_ms> number of milliseconds
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u08 timerThres;
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u32 ticRateHz;
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u32 pause;
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// capture current pause timer value
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timerThres = inb(TCNT0);
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// reset pause timer overflow count
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TimerPauseReg = 0;
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// calculate delay for [pause_ms] milliseconds
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// prescaler division = 1<<(pgm_read_byte(TimerPrescaleFactor+inb(TCCR0)))
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ticRateHz = F_CPU/timer0GetPrescaler();
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// precision management
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// prevent overflow and precision underflow
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// -could add more conditions to improve accuracy
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if( ((ticRateHz < 429497) && (pause_ms <= 10000)) )
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pause = (pause_ms*ticRateHz)/1000;
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else
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pause = pause_ms*(ticRateHz/1000);
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// loop until time expires
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while( ((TimerPauseReg<<8) | inb(TCNT0)) < (pause+timerThres) )
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{
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if( TimerPauseReg < (pause>>8));
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{
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// save power by idling the processor
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set_sleep_mode(SLEEP_MODE_IDLE);
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sleep_mode();
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}
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}
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/* old inaccurate code, for reference
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// calculate delay for [pause_ms] milliseconds
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u16 prescaleDiv = 1<<(pgm_read_byte(TimerPrescaleFactor+inb(TCCR0)));
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u32 pause = (pause_ms*(F_CPU/(prescaleDiv*256)))/1000;
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TimerPauseReg = 0;
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while(TimerPauseReg < pause);
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*/
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}
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void timer0ClearOverflowCount(void)
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{
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// clear the timer overflow counter registers
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Timer0Reg0 = 0; // initialize time registers
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}
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long timer0GetOverflowCount(void)
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{
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// return the current timer overflow count
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// (this is since the last timer0ClearOverflowCount() command was called)
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return Timer0Reg0;
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}
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#ifdef TCNT2 // support timer2 only if it exists
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void timer2ClearOverflowCount(void)
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{
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// clear the timer overflow counter registers
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Timer2Reg0 = 0; // initialize time registers
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}
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long timer2GetOverflowCount(void)
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{
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// return the current timer overflow count
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// (this is since the last timer2ClearOverflowCount() command was called)
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return Timer2Reg0;
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}
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#endif
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void timer1PWMInit(u08 bitRes)
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{
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// configures timer1 for use with PWM output
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// on OC1A and OC1B pins
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// enable timer1 as 8,9,10bit PWM
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if(bitRes == 9)
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{ // 9bit mode
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sbi(TCCR1A,PWM11);
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cbi(TCCR1A,PWM10);
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}
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else if( bitRes == 10 )
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{ // 10bit mode
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sbi(TCCR1A,PWM11);
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sbi(TCCR1A,PWM10);
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}
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else
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{ // default 8bit mode
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cbi(TCCR1A,PWM11);
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sbi(TCCR1A,PWM10);
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}
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// clear output compare value A
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outb(OCR1AH, 0);
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outb(OCR1AL, 0);
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// clear output compare value B
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outb(OCR1BH, 0);
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outb(OCR1BL, 0);
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}
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#ifdef WGM10
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// include support for arbitrary top-count PWM
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// on new AVR processors that support it
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void timer1PWMInitICR(u16 topcount)
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{
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// set PWM mode with ICR top-count
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cbi(TCCR1A,WGM10);
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sbi(TCCR1A,WGM11);
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sbi(TCCR1B,WGM12);
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sbi(TCCR1B,WGM13);
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// set top count value
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ICR1 = topcount;
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// clear output compare value A
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OCR1A = 0;
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// clear output compare value B
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OCR1B = 0;
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}
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#endif
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void timer1PWMOff(void)
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{
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// turn off timer1 PWM mode
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cbi(TCCR1A,PWM11);
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cbi(TCCR1A,PWM10);
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// set PWM1A/B (OutputCompare action) to none
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timer1PWMAOff();
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timer1PWMBOff();
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}
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void timer1PWMAOn(void)
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{
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// turn on channel A (OC1A) PWM output
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// set OC1A as non-inverted PWM
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sbi(TCCR1A,COM1A1);
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cbi(TCCR1A,COM1A0);
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}
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void timer1PWMBOn(void)
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{
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// turn on channel B (OC1B) PWM output
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// set OC1B as non-inverted PWM
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sbi(TCCR1A,COM1B1);
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cbi(TCCR1A,COM1B0);
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}
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void timer1PWMAOff(void)
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{
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// turn off channel A (OC1A) PWM output
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// set OC1A (OutputCompare action) to none
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cbi(TCCR1A,COM1A1);
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cbi(TCCR1A,COM1A0);
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}
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void timer1PWMBOff(void)
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{
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// turn off channel B (OC1B) PWM output
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// set OC1B (OutputCompare action) to none
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cbi(TCCR1A,COM1B1);
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cbi(TCCR1A,COM1B0);
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}
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void timer1PWMASet(u16 pwmDuty)
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{
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// set PWM (output compare) duty for channel A
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// this PWM output is generated on OC1A pin
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// NOTE: pwmDuty should be in the range 0-255 for 8bit PWM
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// pwmDuty should be in the range 0-511 for 9bit PWM
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// pwmDuty should be in the range 0-1023 for 10bit PWM
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//outp( (pwmDuty>>8), OCR1AH); // set the high 8bits of OCR1A
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//outp( (pwmDuty&0x00FF), OCR1AL); // set the low 8bits of OCR1A
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OCR1A = pwmDuty;
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}
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void timer1PWMBSet(u16 pwmDuty)
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{
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// set PWM (output compare) duty for channel B
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// this PWM output is generated on OC1B pin
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// NOTE: pwmDuty should be in the range 0-255 for 8bit PWM
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// pwmDuty should be in the range 0-511 for 9bit PWM
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// pwmDuty should be in the range 0-1023 for 10bit PWM
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//outp( (pwmDuty>>8), OCR1BH); // set the high 8bits of OCR1B
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//outp( (pwmDuty&0x00FF), OCR1BL); // set the low 8bits of OCR1B
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OCR1B = pwmDuty;
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}
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//! Interrupt handler for tcnt0 overflow interrupt
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TIMER_INTERRUPT_HANDLER(TIMER0_OVF_vect)
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{
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Timer0Reg0++; // increment low-order counter
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// increment pause counter
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TimerPauseReg++;
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// if a user function is defined, execute it too
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if(TimerIntFunc[TIMER0OVERFLOW_INT])
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TimerIntFunc[TIMER0OVERFLOW_INT]();
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}
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//! Interrupt handler for tcnt1 overflow interrupt
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TIMER_INTERRUPT_HANDLER(TIMER1_OVF_vect)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER1OVERFLOW_INT])
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TimerIntFunc[TIMER1OVERFLOW_INT]();
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}
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#if (!(defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
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defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
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defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \
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defined(__AVR_AT90USB162__) || defined(__AVR_AT90USB82__) || \
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defined(__AVR_ATmega32U6__) || defined(__AVR_ATmega32U2__)))
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// support timer2 only if it exists, but it is different on the USB AVRs
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//! Interrupt handler for tcnt2 overflow interrupt
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TIMER_INTERRUPT_HANDLER(SIG_OVERFLOW2)
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{
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Timer2Reg0++; // increment low-order counter
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER2OVERFLOW_INT])
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TimerIntFunc[TIMER2OVERFLOW_INT]();
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}
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#endif
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#ifdef OCR0
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// include support for Output Compare 0 for new AVR processors that support it
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//! Interrupt handler for OutputCompare0 match (OC0) interrupt
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TIMER_INTERRUPT_HANDLER(TIMER0_COMPA_vect)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER0OUTCOMPARE_INT])
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TimerIntFunc[TIMER0OUTCOMPARE_INT]();
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}
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#endif
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//! Interrupt handler for CutputCompare1A match (OC1A) interrupt
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TIMER_INTERRUPT_HANDLER(TIMER1_COMPA_vect)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER1OUTCOMPAREA_INT])
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TimerIntFunc[TIMER1OUTCOMPAREA_INT]();
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}
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//! Interrupt handler for OutputCompare1B match (OC1B) interrupt
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TIMER_INTERRUPT_HANDLER(TIMER1_COMPB_vect)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER1OUTCOMPAREB_INT])
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TimerIntFunc[TIMER1OUTCOMPAREB_INT]();
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}
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//! Interrupt handler for InputCapture1 (IC1) interrupt
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TIMER_INTERRUPT_HANDLER(TIMER1_CAPT_vect)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER1INPUTCAPTURE_INT])
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TimerIntFunc[TIMER1INPUTCAPTURE_INT]();
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}
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//! Interrupt handler for OutputCompare2 match (OC2) interrupt
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// USB AVRs have incompatible Timer2
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#if (!(defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
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defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
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defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \
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defined(__AVR_AT90USB162__) || defined(__AVR_AT90USB82__) || \
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defined(__AVR_ATmega32U6__) || defined(__AVR_ATmega32U2__)))
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TIMER_INTERRUPT_HANDLER(SIG_OUTPUT_COMPARE2)
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{
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// if a user function is defined, execute it
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if(TimerIntFunc[TIMER2OUTCOMPARE_INT])
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TimerIntFunc[TIMER2OUTCOMPARE_INT]();
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}
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#endif
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