46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
/*
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Demo of using interrupts for doing what they do best --
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two things at once.
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Flashes LED0 at a fixed rate, interrupting whenever button is pressed.
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*/
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// ------- Preamble -------- //
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#include <avr/io.h>
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#include <util/delay.h>
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#include <avr/interrupt.h>
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#include "pinDefines.h"
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ISR(INT0_vect) { /* Run every time there is a change on button */
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if (bit_is_clear(BUTTON_PIN, BUTTON)) {
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LED_PORT |= (1 << LED1);
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}
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else {
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LED_PORT &= ~(1 << LED1);
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}
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}
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void initInterrupt0(void) {
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EIMSK |= (1 << INT0); /* enable INT0 */
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EICRA |= (1 << ISC00); /* trigger when button changes */
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sei(); /* set (global) interrupt enable bit */
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}
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int main(void) {
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// -------- Inits --------- //
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LED_DDR = 0xff; /* all LEDs active */
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BUTTON_PORT |= (1 << BUTTON); /* pullup */
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initInterrupt0();
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// ------ Event loop ------ //
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while (1) {
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_delay_ms(200);
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LED_PORT ^= (1 << LED0);
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} /* End event loop */
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return 0; /* This line is never reached */
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}
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