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/*
* Copyright © 2017 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <ao.h>
/*
* ATtiny ADC interface
*/
uint16_t
ao_adc_read(uint8_t mux)
{
uint8_t low, high;
/* Set the mux */
ADMUX = mux;
/* Start conversion */
ADCSRA = ((1 << ADEN) |
(1 << ADSC) |
(0 << ADATE) |
(0 << ADIF) |
(0 << ADIE) |
(0 << ADPS2) |
(0 << ADPS1) |
(0 << ADPS0));
/* Await conversion complete */
while ((ADCSRA & (1 << ADSC)) != 0)
;
/* Read low first */
low = ADCL;
high = ADCH;
return (((uint16_t) high) << 8) | low;
}
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