41 lines
536 B
C
41 lines
536 B
C
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <stdlib.h>
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#include <lib/timer.h>
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timer_cb cur_cb;
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void start_timer(timer_cb cb) {
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cur_cb = cb;
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cli();
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/* set timer0 to CTC & prescaler 64 → 125kHz increment */
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TCCR0A = (1 << WGM01);
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TCCR0B = (1 << CS00) | (1 << CS01);
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OCR0A = 4; /* TOP */
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TCNT0 = 0;
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/*enable interrupt */
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TIMSK0 |= (1 << OCIE0A);
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sei();
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}
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void stop_timer(void) {
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cli();
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TIMSK0 = 0;
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sei();
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cur_cb = NULL;
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}
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ISR(TIMER0_COMPA_vect,ISR_NOBLOCK) {
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if(cur_cb != NULL) {
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cur_cb();
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}
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}
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