68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
/* ******************************************************** *
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*
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* Simple program with avr-gcc and ATtiny13
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* -------------------------------------------------------- *
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* Created on: 07.06.2016
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* Author: Paolo Iocco
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* ******************************************************** */
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/* ******************************************************** *
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ATtiny 13/45/85 Pin map
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+--\/--+
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/Reset ADC0 PB5 -|1° 8|- Vcc
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ADC3 PB3 -|2 7|- PB2 ADC1 SCK
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ADC2 PB4 -|3 6|- PB1 OC0B MISO AIN1
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GND -|4 5|- PB0 OC0A MOSI AIN0
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+------+
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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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