29 lines
824 B
C
29 lines
824 B
C
#include <avr/io.h>
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#include "utils.h"
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#include "bitmanip.h"
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#include "timer.h"
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#define PERIOD 500
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#define PRESCALE_VALUE 1024 // can be 1, 8, 64, 256, 1024
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// led turns on and off every PERIOD ms using CTC timer
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int main() {
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MODE_OUTPUT(LED2);
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TCCR1B |= (1 << WGM12); // Table 16-4 : set timer in CTC (Clear Time on Compare) mode, use bit WGM12, located in register TCCR1B (16.11.2)
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TCCR1A |= (1 << COM1A0); // 14.3.1 : set Compare Output with COM1A0, it toggles OC1A on compare match (Table 16-1), OC1A is alternate function for PORTB1 (Table 14-3)
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OCR1A = TIME_MS(PERIOD, PRESCALE_VALUE); // Table 16-4 : set CTC compare value on channel A, the counter is cleared to zero when the counter value (TCNT1) matches the OCR1A register
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TCCR1B |= (PRESCALE_SET(PRESCALE_VALUE));
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while(1);
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}
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