59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
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/* *********************************************** *
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* main.c *
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* Simple ATTiny13a program *
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* ----------------------------------------------- *
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* Created on: 20.07.2016 *
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* Author: q242695 *
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************************************************* */
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#include "main.h"
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void adc_setup (void)
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{
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// Set the ADC input to PB2/ADC1
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ADMUX |= (1 << MUX0);
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ADMUX |= (1 << ADLAR);
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// Set the prescaler to clock/128 & enable ADC
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ADCSRA |= (1 << ADPS1) | (1 << ADPS0) | (1 << ADEN);
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}
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int adc_read (void)
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{
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// Start the conversion
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ADCSRA |= (1 << ADSC);
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// Wait for it to finish
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while (ADCSRA & (1 << ADSC));
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return ADCH;
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}
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void pwm_setup (void)
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{
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// Set Timer 0 prescaler to clock/8.
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// At 9.6 MHz this is 1.2 MHz.
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TCCR0B |= (1 << CS01) | (1 << CS00);
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// Set to 'Fast PWM' mode
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TCCR0A |= (1 << WGM01) | (1 << WGM00);
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// Clear OC0B output on compare match, upwards counting.
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TCCR0A |= (1 << COM0B1);
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}
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void pwm_write (int val)
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{
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OCR0B = val;
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}
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int main (void)
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{
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int adc_in;
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// LED is an output.
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DDRB |= (1 << LED);
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adc_setup();
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pwm_setup();
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while (1) {
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// Get the ADC value
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adc_in = adc_read();
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// Now write it to the PWM counter
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pwm_write(adc_in);
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}
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}
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