qmk_firmware/platforms/avr/drivers/analog.h

52 lines
1.7 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/>.
*/
#pragma once
#include <stdint.h>
#include "quantum.h"
#ifdef __cplusplus
extern "C" {
#endif
void analogReference(uint8_t mode);
int16_t analogReadPin(pin_t pin);
uint8_t pinToMux(pin_t pin);
int16_t adc_read(uint8_t mux);
#ifdef __cplusplus
}
#endif
#define ADC_REF_EXTERNAL 0 // AREF, Internal Vref turned off
#define ADC_REF_POWER _BV(REFS0) // AVCC with external capacitor on AREF pin
#define ADC_REF_INTERNAL (_BV(REFS1) | _BV(REFS0)) // Internal 2.56V Voltage Reference with external capacitor on AREF pin (1.1V for 328P)
// These prescaler values are for high speed mode, ADHSM = 1
#if F_CPU == 16000000L || F_CPU == 12000000L
# define ADC_PRESCALER (_BV(ADPS2) | _BV(ADPS1)) // /64
#elif F_CPU == 8000000L
# define ADC_PRESCALER (_BV(ADPS2) | _BV(ADPS0)) // /32
#elif F_CPU == 4000000L
# define ADC_PRESCALER (_BV(ADPS2)) // /16
#elif F_CPU == 2000000L
# define ADC_PRESCALER (_BV(ADPS1) | _BV(ADPS0)) // /8
#elif F_CPU == 1000000L
# define ADC_PRESCALER _BV(ADPS1) // /4
#else
# define ADC_PRESCALER _BV(ADPS0) // /2
#endif