我已經爲Atmega128寫了一個pwm代碼。我在比較匹配時使用非反相脈衝的快速PWM模式,我需要在特定時間更改OCR0值。但它並沒有改變。任何人都知道這裏有什麼問題?pwm值不變
#include <avr/interrupt.h>
#include <avr/io.h>
uint8_t tick_1sec;
void timer1_init(void) // 1 second timer
{
OCR1A = 15624;
TIMSK |= (1<<OCIE1A);
TCCR1B = (1<<WGM12); //CTC mode
TCCR1B |= (1<<CS12)|(0<<CS11)|(1<<CS10);
}
ISR(TIMER1_COMPA_vect) //1 second interrupt
{
cli();
tick_1sec = 1;
sei();
}
void timer0_init(void) // fast pwm with OC0 non-inverting mode
{
TCCR0 = (1<<FOC0)|(1<<WGM01)|(1<<WGM00);
TCCR0 |= (1<<COM01)|(0<<COM00);
TCCR0 |= (1<<CS02)|(1<<CS01)|(1<<CS00);
OCR0 = 63;
TIMSK |= (1<<OCIE0);
}
int main(void)
{
uint8_t t = 0;
DDRB = 0xFF;
timer0_init();
timer1_init();
sei();
while(1){
if (tick_1sec)
{
tick_1sec = 0;
t++;
if (t == 10){
OCR0 = 127;
}
else if (t == 20){
OCR0 = 191;
}
else if (t == 30){
OCR0 = 63;
t = 0;
}
}
}
return 0;
}
請正確格式化您的代碼,並使用四個空格。 –
我編輯過它們。 –