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50 lines
981 B
50 lines
981 B
8 years ago
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#include <avr/io.h>
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#include <stdint.h>
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#include "calc.h"
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#include "adc.h"
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/** Initialize the ADC */
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void adc_init(enum ADC_Prescaller presc)
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{
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ADCSRA |= presc; // 128 prescaler -> 125 kHz
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ADMUX |= _BV(REFS0); // Voltage reference
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sbi(ADCSRA, ADEN); // Enable ADC
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}
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/** Disable ADC */
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void adc_disable(void)
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{
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cbi(ADCSRA, ADEN);
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}
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/** Enable ADC */
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void adc_enable(void)
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{
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sbi(ADCSRA, ADEN);
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}
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static void adc_convert(uint8_t channel)
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{
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set_low_nibble(ADMUX, channel); // Select channel to sample
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sbi(ADMUX, ADLAR); // Align result to left
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sbi(ADCSRA, ADSC); // Start conversion
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while (bit_is_high(ADCSRA, ADSC)); // Wait for it...
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}
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/** Sample analog pin with 8-bit precision */
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uint8_t adc_read_byte(uint8_t channel)
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{
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adc_convert(channel);
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return ADCH; // The upper 8 bits of ADC result
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}
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/** Sample analog pin with 10-bit precision */
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uint16_t adc_read_word(uint8_t channel)
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{
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adc_convert(channel);
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return ADCW; // The whole ADC word (10 bits)
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}
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