keychron_qmk_firmware/drivers/avr/analog.h
2019-08-30 15:01:52 -07:00

53 lines
1.6 KiB
C

/* Copyright 2015 Jack Humbert
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _analog_h_included__
#define _analog_h_included__
#include <stdint.h>
void analogReference(uint8_t mode);
int16_t analogRead(uint8_t pin);
int16_t adc_read(uint8_t mux);
#define ADC_REF_POWER (1 << REFS0)
#define ADC_REF_INTERNAL ((1 << REFS1) | (1 << REFS0))
#define ADC_REF_EXTERNAL (0)
// These prescaler values are for high speed mode, ADHSM = 1
#if F_CPU == 16000000L
# define ADC_PRESCALER ((1 << ADPS2) | (1 << ADPS1))
#elif F_CPU == 8000000L
# define ADC_PRESCALER ((1 << ADPS2) | (1 << ADPS0))
#elif F_CPU == 4000000L
# define ADC_PRESCALER ((1 << ADPS2))
#elif F_CPU == 2000000L
# define ADC_PRESCALER ((1 << ADPS1) | (1 << ADPS0))
#elif F_CPU == 1000000L
# define ADC_PRESCALER ((1 << ADPS1))
#else
# define ADC_PRESCALER ((1 << ADPS0))
#endif
// some avr-libc versions do not properly define ADHSM
#if defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
# if !defined(ADHSM)
# define ADHSM (7)
# endif
#endif
#endif