PWM.rar_AVR PWM_AVR PWM mega16_pwm avr mega16

#include <stdlib.h> #include <iom16v.h> #include <macros.h> //interrupt???????????? typedef unsigned short int uint16_t; /* from 50 to 950 */ uint16_t duty_cycle; uint16_t i; uint16_t j; /* #pragma interrupt_handler timer0_ovf_isr:10 //??????????????? void timer0_ovf_isr(void) // When TCNT1 overflow.......... { // if the duty is at 95% the restart from 5% if (duty_cycle > 950) duty_cycle = 50; DDRA = 0x03; PORTA = 0x03; // increment the duty cycle by 1 step at the time wich is // 0.1%, in this way I will complete 100% in 2 seconds (1000 step) duty_cycle=duty_cycle+100; // set the level where the output pin OC1A will toggle OCR1A = duty_cycle; // set the level where the output pin OC1B will toggle // this will be the inverse of OC1A level OCR1B = 1000 - duty_cycle; TCNT1 = 0x00; DelayMs(20); PORTA = 0x00; } */ void DelayMs(int count) //Gives a delay of 1 Ms { int i; int j; for(i=0;i<count;i++) { for(j=0;j<5000;j++); } } void counter_setup(void) { /* Pin OC1A & B set to output */ DDRD |= (1<<PD4) | (1<<PD5) |(1<<PD7); DDRB |= (1<<PB3) ; /* Clear OC1A & B on compare match, set it at BOTTOM. Waveform generation mode on 14, see datasheet */ TCCR1A = (1<<COM1A1)|(1<<COM1B1)|(0<<COM1A0)|(0<<COM1B0)|(1<<WGM11); TCCR1B = (1<<WGM13)|(1<<WGM12); TCCR0=(1<<WGM00)|(1<<WGM01)|(1<<COM00)|(1<<COM01); TCCR2=(1<<WGM20)|(1<<WGM21)|(1<<COM20)|(1<<COM21); /* TOP value*/ ICR1 =500; TCNT0 = 0x00; TCNT2 = 0x00; /* start with a duty of 50% */ OCR1A = 430; duty_cycle=OCR1A; OCR1B = 59; OCR0 = 100; //set compare 占空比 OCR2 = 150; /* enable interrupt on timer overflow */ //TIMSK = (1<<OCIE2)|(1<<TOIE2); } int main(void) { /* prepare everything */ counter_setup(); /* enable interrupt */ SEI(); /* start the counter with prescaler = 256 */ TCCR1B |= (1<<CS12)|(0<<CS11)|(0<<CS10); /* start the counter with prescaler = 64 */ TCCR0 |=(0<<CS02)|(1<<CS01)|(0<<CS00); /* start the counter with prescaler = 32 */ TCCR2 |=(0<<CS22)|(1<<CS21)|(1<<CS20); /* Infinite loop doing nothing, everything is handled by the IRQ routine called 500 times x second. */ for (;;) { if (OCR1A > 492) OCR1A = 430; /*if (OCR1B > 900) OCR1B = 100;*/ DelayMs(1000); OCR1A=OCR1A+5; //OCR1B=OCR1B+100; } /* just for correct looking code, disable irq and terminate */ CLI(); return(0); }