From a8320f20f76782789b274f7a8c3e3ad4278a075c Mon Sep 17 00:00:00 2001 From: fauxpark Date: Sun, 8 Dec 2019 12:11:29 +1100 Subject: Improve support and docs for ADC driver (#7191) * Improve support and docs for ADC driver * Comment ADC channels * Move to Makers and Modders section, and fix usage instructions * Flesh out intro * Superscript 328P note * Fix pin_to_mux LUT * Support USB64/1287 as well * analogReadPin() defaults to 0V mux on invalid pin * Update pinToMux() function documentation * Dot * Accept (some of) the `qmk cformat` changes * Do clang-format properly * More wording tweaks * Link to encoder docs --- drivers/avr/analog.c | 110 ++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 92 insertions(+), 18 deletions(-) (limited to 'drivers/avr/analog.c') diff --git a/drivers/avr/analog.c b/drivers/avr/analog.c index 1a8da4261d..abe478b712 100644 --- a/drivers/avr/analog.c +++ b/drivers/avr/analog.c @@ -14,24 +14,31 @@ * along with this program. If not, see . */ -// Simple analog to digitial conversion - #include #include #include #include "analog.h" -static uint8_t aref = (1 << REFS0); // default to AREF = Vcc +static uint8_t aref = ADC_REF_POWER; -void analogReference(uint8_t mode) { aref = mode & 0xC0; } +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__) - static const uint8_t PROGMEM pin_to_mux[] = {0x00, 0x01, 0x04, 0x05, 0x06, 0x07, 0x25, 0x24, 0x23, 0x22, 0x21, 0x20}; + // 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_AT90USB1286__) +#elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega328P__) if (pin >= 8) return 0; return adc_read(pin); #else @@ -39,20 +46,87 @@ int16_t analogRead(uint8_t pin) { #endif } -// Mux input +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__) + 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 + } +} + int16_t adc_read(uint8_t mux) { -#if defined(__AVR_AT90USB162__) - return 0; -#else uint8_t low; - ADCSRA = (1 << ADEN) | ADC_PRESCALER; // enable ADC - ADCSRB = (1 << ADHSM) | (mux & 0x20); // high speed mode - ADMUX = aref | (mux & 0x1F); // configure mux input - ADCSRA = (1 << ADEN) | ADC_PRESCALER | (1 << ADSC); // start the conversion - while (ADCSRA & (1 << ADSC)) - ; // wait for result - low = ADCL; // must read LSB first - return (ADCH << 8) | low; // must read MSB only once! + // 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! + return (ADCH << 8) | low; } -- cgit v1.2.3