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Diffstat (limited to 'spaghetti-monster/fsm-adc.c')
| -rw-r--r-- | spaghetti-monster/fsm-adc.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/spaghetti-monster/fsm-adc.c b/spaghetti-monster/fsm-adc.c new file mode 100644 index 0000000..11468b9 --- /dev/null +++ b/spaghetti-monster/fsm-adc.c @@ -0,0 +1,136 @@ +/* + * fsm-adc.c: ADC (voltage, temperature) functions for SpaghettiMonster. + * + * Copyright (C) 2017 Selene ToyKeeper + * + * 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 3 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 FSM_ADC_C +#define FSM_ADC_C + +inline void ADC_on() +{ + // read voltage on VCC by default + // disable digital input on VCC pin to reduce power consumption + //DIDR0 |= (1 << ADC_DIDR); // FIXME: unsure how to handle for VCC pin + // VCC / 1.1V reference + ADMUX = ADMUX_VCC; + // enable, start, prescale + ADCSRA = (1 << ADEN) | (1 << ADSC) | ADC_PRSCL; +} + +inline void ADC_off() { + ADCSRA &= ~(1<<ADEN); //ADC off +} + +// TODO: is this better done in main() or WDT()? +ISR(ADC_vect) { + static uint8_t adc_step = 0; + #ifdef USE_LVP + #ifdef USE_LVP_AVG + #define NUM_VOLTAGE_VALUES 4 + static int16_t voltage_values[NUM_VOLTAGE_VALUES]; + #endif + static uint8_t lvp_timer = 0; + static uint8_t lvp_lowpass = 0; + #define LVP_TIMER_START 50 // ticks between LVP warnings + #define LVP_LOWPASS_STRENGTH 4 + #endif + + #ifdef USE_THERMAL_REGULATION + #define NUM_THERMAL_VALUES 4 + #define ADC_STEPS 4 + static int16_t temperature_values[NUM_THERMAL_VALUES]; + #else + #define ADC_STEPS 2 + #endif + + uint16_t measurement = ADC; // latest 10-bit ADC reading + + adc_step = (adc_step + 1) & (ADC_STEPS-1); + + #ifdef USE_LVP + // voltage + if (adc_step == 1) { + #ifdef USE_LVP_AVG + // prime on first execution + if (voltage == 0) { + for(uint8_t i=0; i<NUM_VOLTAGE_VALUES; i++) + voltage_values[i] = measurement; + voltage = 42; // Life, the Universe, and Everything (*) + } else { + uint16_t total = 0; + uint8_t i; + for(i=0; i<NUM_VOLTAGE_VALUES-1; i++) { + voltage_values[i] = voltage_values[i+1]; + total += voltage_values[i]; + } + voltage_values[i] = measurement; + total += measurement; + total = total >> 2; + + voltage = (uint16_t)(1.1*1024*10)/total + VOLTAGE_FUDGE_FACTOR; + } + #else // no USE_LVP_AVG + // calculate actual voltage: volts * 10 + // ADC = 1.1 * 1024 / volts + // volts = 1.1 * 1024 / ADC + voltage = (uint16_t)(1.1*1024*10)/measurement + VOLTAGE_FUDGE_FACTOR; + #endif + // if low, callback EV_voltage_low / EV_voltage_critical + // (but only if it has been more than N ticks since last call) + if (lvp_timer) { + lvp_timer --; + } else { // it has been long enough since the last warning + if (voltage < VOLTAGE_LOW) { + if (lvp_lowpass < LVP_LOWPASS_STRENGTH) { + lvp_lowpass ++; + } else { + // try to send out a warning + //uint8_t err = emit(EV_voltage_low, 0); + //uint8_t err = emit_now(EV_voltage_low, 0); + emit(EV_voltage_low, 0); + //if (!err) { + // on successful warning, reset counters + lvp_timer = LVP_TIMER_START; + lvp_lowpass = 0; + //} + } + } else { + // voltage not low? reset count + lvp_lowpass = 0; + } + } + } + #endif // ifdef USE_LVP + + // TODO: temperature + + // start another measurement for next time + #ifdef USE_THERMAL_REGULATION + #ifdef USE_LVP + if (adc_step < 2) ADMUX = ADMUX_VCC; + else ADMUX = ADMUX_THERM; + #else + ADMUX = ADMUX_THERM; + #endif + #else + #ifdef USE_LVP + ADMUX = ADMUX_VCC; + #endif + #endif +} + +#endif |