51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
/* PWM Demo with serial control over three LEDs */
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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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#include "USART.h"
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static inline void initTimers(void) {
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// Timer 1 A,B
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TCCR1A |= (1 << WGM10); /* Fast PWM mode, 8-bit */
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TCCR1B |= (1 << WGM12); /* Fast PWM mode, pt.2 */
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TCCR1B |= (1 << CS11); /* PWM Freq = F_CPU/8/256 */
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TCCR1A |= (1 << COM1A1); /* PWM output on OCR1A */
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TCCR1A |= (1 << COM1B1); /* PWM output on OCR1B */
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// Timer 2
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TCCR2A |= (1 << WGM20); /* Fast PWM mode */
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TCCR2A |= (1 << WGM21); /* Fast PWM mode, pt.2 */
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TCCR2B |= (1 << CS21); /* PWM Freq = F_CPU/8/256 */
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TCCR2A |= (1 << COM2A1); /* PWM output on OCR2A */
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}
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int main(void) {
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uint8_t brightness;
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// -------- Inits --------- //
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initTimers();
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initUSART();
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printString("-- LED PWM Demo --\r\n");
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/* enable output on LED pins, triggered by PWM hardware */
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LED_DDR |= (1 << LED1);
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LED_DDR |= (1 << LED2);
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LED_DDR |= (1 << LED3);
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// ------ Event loop ------ //
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while (1) {
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printString("\r\nEnter (0-255) for PWM duty cycle: ");
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brightness = getNumber();
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OCR2A = OCR1B;
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OCR1B = OCR1A;
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OCR1A = 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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