/* 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/>. */ #include <avr/io.h> #include <avr/pgmspace.h> #include <stdint.h> #include "analog.h" static uint8_t aref = ADC_REF_POWER; void analogReference(uint8_t mode) { aref = mode & (_BV(REFS1) | _BV(REFS0)); } // Arduino compatible pin input int16_t analogRead(uint8_t pin) { #if defined(__AVR_ATmega32U4__) // clang-format off static const uint8_t PROGMEM pin_to_mux[] = { //A0 A1 A2 A3 A4 A5 //F7 F6 F5 F4 F1 F0 0x07, 0x06, 0x05, 0x04, 0x01, 0x00, //A6 A7 A8 A9 A10 A11 //D4 D7 B4 B5 B6 D6 0x20, 0x22, 0x23, 0x24, 0x25, 0x21 }; // clang-format on if (pin >= 12) return 0; return adc_read(pgm_read_byte(pin_to_mux + pin)); #elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__) if (pin >= 8) return 0; return adc_read(pin); #else return 0; #endif } int16_t analogReadPin(pin_t pin) { return adc_read(pinToMux(pin)); } uint8_t pinToMux(pin_t pin) { switch (pin) { // clang-format off #if defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) case F0: return 0; // ADC0 case F1: return _BV(MUX0); // ADC1 case F2: return _BV(MUX1); // ADC2 case F3: return _BV(MUX1) | _BV(MUX0); // ADC3 case F4: return _BV(MUX2); // ADC4 case F5: return _BV(MUX2) | _BV(MUX0); // ADC5 case F6: return _BV(MUX2) | _BV(MUX1); // ADC6 case F7: return _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // ADC7 default: return _BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // 0V #elif defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) case F0: return 0; // ADC0 case F1: return _BV(MUX0); // ADC1 case F4: return _BV(MUX2); // ADC4 case F5: return _BV(MUX2) | _BV(MUX0); // ADC5 case F6: return _BV(MUX2) | _BV(MUX1); // ADC6 case F7: return _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // ADC7 case D4: return _BV(MUX5); // ADC8 case D6: return _BV(MUX5) | _BV(MUX0); // ADC9 case D7: return _BV(MUX5) | _BV(MUX1); // ADC10 case B4: return _BV(MUX5) | _BV(MUX1) | _BV(MUX0); // ADC11 case B5: return _BV(MUX5) | _BV(MUX2); // ADC12 case B6: return _BV(MUX5) | _BV(MUX2) | _BV(MUX0); // ADC13 default: return _BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // 0V #elif defined(__AVR_ATmega32A__) case A0: return 0; // ADC0 case A1: return _BV(MUX0); // ADC1 case A2: return _BV(MUX1); // ADC2 case A3: return _BV(MUX1) | _BV(MUX0); // ADC3 case A4: return _BV(MUX2); // ADC4 case A5: return _BV(MUX2) | _BV(MUX0); // ADC5 case A6: return _BV(MUX2) | _BV(MUX1); // ADC6 case A7: return _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // ADC7 default: return _BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // 0V #elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__) case C0: return 0; // ADC0 case C1: return _BV(MUX0); // ADC1 case C2: return _BV(MUX1); // ADC2 case C3: return _BV(MUX1) | _BV(MUX0); // ADC3 case C4: return _BV(MUX2); // ADC4 case C5: return _BV(MUX2) | _BV(MUX0); // ADC5 // ADC7:6 not present in DIP package and not shared by GPIO pins default: return _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0); // 0V #endif // clang-format on } return 0; } int16_t adc_read(uint8_t mux) { uint16_t low; // Enable ADC and configure prescaler ADCSRA = _BV(ADEN) | ADC_PRESCALER; #if defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) // High speed mode and ADC8-13 ADCSRB = _BV(ADHSM) | (mux & _BV(MUX5)); #elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) // High speed mode only ADCSRB = _BV(ADHSM); #endif // Configure mux input #if defined(MUX4) ADMUX = aref | (mux & (_BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0))); #else ADMUX = aref | (mux & (_BV(MUX3) | _BV(MUX2) | _BV(MUX1) | _BV(MUX0))); #endif // Start the conversion ADCSRA |= _BV(ADSC); // Wait for result while (ADCSRA & _BV(ADSC)) ; // Must read LSB first low = ADCL; // Must read MSB only once! low |= (ADCH << 8); // turn off the ADC ADCSRA &= ~(1 << ADEN); return low; }