46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
/* Quick and dirty PWM Demo */
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// ------- Preamble -------- //
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#include <avr/io.h> /* Defines pins, ports, etc */
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#include <util/delay.h> /* Functions to waste time */
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#include "pinDefines.h"
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#define LED_DELAY 20 /* microseconds */
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void pwmAllPins(uint8_t brightness) {
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uint8_t i;
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LED_PORT = 0xff; /* turn on */
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for (i = 0; i < 255; i++) {
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if (i >= brightness) { /* once it's been on long enough */
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LED_PORT = 0; /* turn off */
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}
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_delay_us(LED_DELAY);
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}
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}
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int main(void) {
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uint8_t brightness = 0;
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int8_t direction = 1;
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// -------- Inits --------- //
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// Init all LEDs
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LED_DDR = 0xff;
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// ------ Event loop ------ //
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while (1) {
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// Brighten and dim
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if (brightness == 0) {
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direction = 1;
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}
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if (brightness == 255) {
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direction = -1;
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}
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brightness += direction;
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pwmAllPins(brightness);
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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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