38 lines
702 B
C
38 lines
702 B
C
#include <avr/io.h>
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#include "intervaltimer.h"
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void intervaltimer_init(void)
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{
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TCCR1A = 0;
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TCCR1B = (1<<WGM12) | (1<<CS12) | (1<<CS00); // CTC, /1024 prescaler
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}
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void intervaltimer_set(int interval_ms)
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{
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static int cur_interval = 0;
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// We are setting TCNT back to zero, and updating
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// the compare match register.
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//
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// To allows for simple repeated calling of this
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// function from the main loop, only touch
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// the counter when the interval changes.
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if (cur_interval != interval_ms) {
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cur_interval = interval_ms;
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TCNT1 = 0;
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OCR1A = interval_ms * (F_CPU/1024) / 1000;
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}
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}
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char intervaltimer_get(void)
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{
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if (TIFR1 & (1<<OCF1A)) {
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TIFR1 = 1<<OCF1A;
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return 1;
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}
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return 0;
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}
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