29 lines
1.0 KiB
C
29 lines
1.0 KiB
C
/*
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Demonstrates using state to detect button presses
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*/
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// ------- Preamble -------- //
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#include <avr/io.h>
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#include "pinDefines.h"
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int main(void) {
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// -------- Inits --------- //
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uint8_t buttonWasPressed; /* state */
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BUTTON_PORT |= (1 << BUTTON); /* enable the pullup on the button */
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LED_DDR = (1 << LED0); /* set up LED for output */
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// ------ Event loop ------ //
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while (1) {
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if (bit_is_clear(BUTTON_PIN, BUTTON)) { /* button is pressed now */
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if (buttonWasPressed == 0) { /* but wasn't last time through */
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LED_PORT ^= (1 << LED0); /* do whatever */
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buttonWasPressed = 1; /* update the state */
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}
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}
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else { /* button is not pressed now */
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buttonWasPressed = 0; /* update the state */
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}
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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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